big ui moment

libs/flexlove/modules/Behavior.lua

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+-- modules/Behavior.lua
+--
+-- Base module for the pluggable behavior system that drives the Behavior &
+-- Mode Unification refactor.
+--
+-- A *behavior* is a small, stateless table produced by `Behavior.new(spec)`
+-- that implements a fixed lifecycle hook set. Concrete behaviors (Clickable,
+-- Scrollable, TextEditable, Selectable, ...) each live in their own module and
+-- are attached to an Element. The Element's `update`/`draw`/save-restore paths
+-- iterate `element.behaviors` and dispatch to the appropriate hooks, replacing
+-- the swarm of `if self.scrollable` / immediate-mode-branch checks previously
+-- hard-coded in Element.lua.
+--
+-- Element.new iterates a registry of behavior prototypes and auto-attaches
+-- whichever return true from `shouldAttach(props)`. Element therefore never
+-- needs to know what an individual behavior does — only that it conforms to
+-- this interface.
+--
+-- Design constraints (locked — tasks 02-13 depend on this API):
+--   * Pure Lua — NO `love` import, NO dependency on utils/Color/Units/ErrorHandler.
+--     Stays fully stub-testable standalone (see testing/__tests__/behavior_test.lua).
+--   * Minimal interface — exactly 6 lifecycle hooks + a `shouldAttach` predicate.
+--     Do NOT add hooks "just in case"; new capabilities become new behaviors,
+--     not new hooks. Extending HOOK_NAMES is an architectural decision that must
+--     be mirrored by every concrete behavior.
+--   * Immutable instances — behavior tables are produced once and treated as
+--     read-only. Per-element runtime state lives on the element (or a subsystem
+--     the behavior attaches), NEVER on the behavior instance itself, so a single
+--     behavior instance can be shared across many elements.
+--
+-- Lifecycle hook contract (each receives the owning element as first argument):
+--   onAttach(element)               — called once when the behavior is attached
+--                                     (element fully constructed). Allocate
+--                                     subsystems / register listeners here.
+--   onDetach(element)               — called once when the behavior is detached
+--                                     (element destroyed / mode switch). Tear
+--                                     down anything onAttach created.
+--   onUpdate(element, dt)           — called every frame from Element:update.
+--   onDraw(element, ctx)            — called every frame from Element:draw; `ctx`
+--                                     is the draw context (viewport transform,
+--                                     scissor state, theme renderer, ...).
+--   saveState(element) -> state     — called during Element save-state; returns
+--                                     a serializable snapshot (or nil) so the
+--                                     behavior's runtime state survives the
+--                                     immediate-mode recreation cycle.
+--   restoreState(element, state)   — called after reconstruction with the
+--                                     snapshot previously returned by saveState.
+--
+-- shouldAttach(props) -> boolean    — class-level predicate (not a hook): given
+--                                     an element's props table, return true if
+--                                     this behavior should be auto-attached.
+--                                     Defaults to false (opt-in).
+
+--- A behavior instance: a frozen table of lifecycle hooks + a shouldAttach
+--- predicate. All hooks are always present (custom override or no-op default).
+---@class Behavior
+---@field onAttach fun(element:table)
+---@field onDetach fun(element:table)
+---@field onUpdate fun(element:table, dt:number)
+---@field onDraw fun(element:table, ctx:table)
+---@field saveState fun(element:table):any
+---@field restoreState fun(element:table, state:any)
+---@field shouldAttach fun(props:table):boolean
+
+local Behavior = {}
+
+-- The fixed, ordered lifecycle hook set. Order is preserved so downstream tasks
+-- (Element behavior iteration) can rely on a deterministic dispatch sequence.
+-- HOOK_NAMES is intentionally NOT extended casually — see file header.
+Behavior.HOOK_NAMES = {
+  "onAttach",
+  "onDetach",
+  "onUpdate",
+  "onDraw",
+  "saveState",
+  "restoreState",
+}
+
+-- Allowlist of spec keys accepted by Behavior.new. Anything else is rejected so
+-- a typo (e.g. `onUpdat`) surfaces immediately instead of silently no-op'ing.
+-- Hook keys (HOOK_NAMES + shouldAttach) MUST be functions; metadata keys
+-- (drawLayer) may hold any value.
+local ALLOWED_KEYS = {
+  onAttach = true,
+  onDetach = true,
+  onUpdate = true,
+  onDraw = true,
+  saveState = true,
+  restoreState = true,
+  shouldAttach = true,
+  drawLayer = true,
+}
+
+-- Spec keys whose values are NOT required to be functions (passive metadata
+-- consumed by dispatch sites, e.g. Element:draw's pre/post-children split).
+local NON_FUNCTION_KEYS = {
+  drawLayer = true,
+}
+
+-- Default no-op hook. Behaviors override only the hooks they need; every other
+-- hook resolves to this so dispatch sites never have to nil-check.
+local function noop() end
+
+-- Default shouldAttach predicate: never auto-attach unless the behavior opts in
+-- by providing its own predicate. This is the safe default — a behavior with no
+-- opinion about which elements it applies to stays inert in the auto-attach
+-- pass (it can still be attached explicitly by name in a later task).
+local function defaultShouldAttach()
+  return false
+end
+
+-- Module-level default predicate exposed for callers/tests that want to
+-- reference the base default directly without constructing an instance.
+Behavior.shouldAttach = defaultShouldAttach
+
+--- Factory: create a frozen behavior instance from a spec table.
+---
+--- `spec` is a table whose keys may be any subset of the 6 lifecycle hook names
+--- plus `shouldAttach`; each value (when present) must be a function. The
+--- returned table contains every lifecycle hook (custom override OR no-op) and
+--- a `shouldAttach` predicate (custom OR always-false default), so dispatch
+--- sites can call any hook unconditionally without nil-checking.
+---
+--- Unknown spec keys and non-function values raise an error immediately so
+--- mistakes fail fast at construction rather than as silent no-ops later.
+---
+---@param spec table|nil spec table overriding select hooks / shouldAttach
+---@return Behavior
+function Behavior.new(spec)
+  spec = spec or {}
+
+  -- Validate spec keys up front so typos surface here, not as silent no-ops.
+  for key, value in pairs(spec) do
+    if not ALLOWED_KEYS[key] then
+      error(string.format("Behavior.new: unknown spec key '%s'", tostring(key)), 2)
+    end
+    if not NON_FUNCTION_KEYS[key] and type(value) ~= "function" then
+      error(string.format("Behavior.new: spec key '%s' must be a function, got %s", tostring(key), type(value)), 2)
+    end
+  end
+
+  local instance = {}
+
+  -- Populate every lifecycle hook: custom override when provided, no-op default
+  -- otherwise. Guarantees `instance.hook` is always callable.
+  for _, hook in ipairs(Behavior.HOOK_NAMES) do
+    instance[hook] = spec[hook] or noop
+  end
+
+  -- shouldAttach defaults to always-false; behaviors opt in by supplying one.
+  instance.shouldAttach = spec.shouldAttach or defaultShouldAttach
+
+  -- drawLayer: optional metadata field (default nil = "background"/pre-children).
+  -- Dispatch sites (Element:draw) use it to split rendering into pre-children
+  -- (background layers) and post-children (overlay layers, e.g. scrollbars).
+  instance.drawLayer = spec.drawLayer
+
+  -- Freeze: prevent adding new fields. Behavior instances are shared, stateless
+  -- objects; runtime state belongs on the element, never on the behavior.
+  -- (Reassigning an existing hook is still possible via direct index write —
+  -- Lua metatables cannot intercept that — but the freeze communicates intent
+  -- and catches accidental field additions.)
+  local mt = {
+    __newindex = function(_, key)
+      error(string.format("Behavior: behavior instances are immutable (cannot set '%s')", tostring(key)), 2)
+    end,
+    --- Mark the metatable so consumers can detect a Behavior instance.
+    ---@return string
+    __tostring = function()
+      return "Behavior"
+    end,
+    __metatable = "Behavior",
+  }
+  setmetatable(instance, mt)
+
+  return instance
+end
+
+--- Type guard: returns true if `value` is a Behavior instance produced by
+--- `Behavior.new`. Used by Element's attach path to validate registry entries
+--- without depending on identity.
+---@param value any
+---@return boolean
+function Behavior.isBehavior(value)
+  return type(value) == "table" and getmetatable(value) == "Behavior"
+end
+
+return Behavior

libs/flexlove/modules/Blur.lua

@@ -0,0 +1,686 @@
+-- Lua 5.2+ compatibility for unpack
+local unpack = table.unpack or unpack
+
+-- Warning cache to prevent duplicate warnings for the same element
+local warningCache = {}
+
+local Cache = {
+  canvases = {},
+  quads = {},
+  blurInstances = {}, -- Cache blur instances by quality
+  blurredCanvases = {}, -- Cache pre-blurred canvases for immediate mode
+  MAX_CANVAS_SIZE = 20,
+  MAX_QUAD_SIZE = 20,
+  MAX_BLURRED_CANVAS_CACHE = 50, -- Maximum cached blurred canvases
+  RADIUS_THRESHOLD = 0.5, -- Skip blur below this radius
+  LARGE_BLUR_THRESHOLD = 250 * 250, -- Warn if blur area exceeds this (250x250px)
+}
+
+--- Round canvas size to nearest bucket for better reuse
+---@param size number Size to bucket
+---@return number bucketSize Bucketed size
+local function bucketSize(size)
+  if size <= 128 then
+    return math.ceil(size / 32) * 32
+  elseif size <= 512 then
+    return math.ceil(size / 64) * 64
+  elseif size <= 1024 then
+    return math.ceil(size / 128) * 128
+  else
+    return math.ceil(size / 256) * 256
+  end
+end
+
+--- Get or create a canvas from cache
+---@param width number Canvas width
+---@param height number Canvas height
+---@return love.Canvas canvas The cached or new canvas
+function Cache.getCanvas(width, height)
+  -- Use bucketed sizes for better cache reuse
+  local bucketedWidth = bucketSize(width)
+  local bucketedHeight = bucketSize(height)
+  local key = string.format("%dx%d", bucketedWidth, bucketedHeight)
+
+  if not Cache.canvases[key] then
+    Cache.canvases[key] = {}
+  end
+
+  local cache = Cache.canvases[key]
+
+  for i, entry in ipairs(cache) do
+    if not entry.inUse then
+      entry.inUse = true
+      return entry.canvas
+    end
+  end
+
+  local canvas = love.graphics.newCanvas(bucketedWidth, bucketedHeight)
+  table.insert(cache, { canvas = canvas, inUse = true })
+
+  if #cache > Cache.MAX_CANVAS_SIZE then
+    local removed = table.remove(cache, 1)
+    if removed and removed.canvas then
+      removed.canvas:release()
+    end
+  end
+
+  return canvas
+end
+
+--- Release a canvas back to the cache
+---@param canvas love.Canvas Canvas to release
+function Cache.releaseCanvas(canvas)
+  for _, sizeCache in pairs(Cache.canvases) do
+    for _, entry in ipairs(sizeCache) do
+      if entry.canvas == canvas then
+        entry.inUse = false
+        return
+      end
+    end
+  end
+end
+
+--- Get or create a quad from cache
+---@param x number X position
+---@param y number Y position
+---@param width number Quad width
+---@param height number Quad height
+---@param sw number Source width
+---@param sh number Source height
+---@return love.Quad quad The cached or new quad
+function Cache.getQuad(x, y, width, height, sw, sh)
+  local key = string.format("%d,%d,%d,%d,%d,%d", x, y, width, height, sw, sh)
+
+  if not Cache.quads[key] then
+    Cache.quads[key] = {}
+  end
+
+  local cache = Cache.quads[key]
+
+  for i, entry in ipairs(cache) do
+    if not entry.inUse then
+      entry.inUse = true
+      return entry.quad
+    end
+  end
+
+  local quad = love.graphics.newQuad(x, y, width, height, sw, sh)
+  table.insert(cache, { quad = quad, inUse = true })
+
+  if #cache > Cache.MAX_QUAD_SIZE then
+    table.remove(cache, 1)
+  end
+
+  return quad
+end
+
+--- Release a quad back to the cache
+---@param quad love.Quad Quad to release
+function Cache.releaseQuad(quad)
+  for _, keyCache in pairs(Cache.quads) do
+    for _, entry in ipairs(keyCache) do
+      if entry.quad == quad then
+        entry.inUse = false
+        return
+      end
+    end
+  end
+end
+
+--- Generate cache key for blurred canvas
+---@param elementId string Element ID
+---@param x number X position
+---@param y number Y position
+---@param width number Width
+---@param height number Height
+---@param radius number Blur radius
+---@param quality number Blur quality
+---@param isBackdrop boolean Whether this is backdrop blur
+---@return string key Cache key
+function Cache.generateBlurCacheKey(elementId, x, y, width, height, radius, quality, isBackdrop)
+  return string.format(
+    "%s:%d:%d:%d:%d:%.1f:%d:%s",
+    elementId,
+    x,
+    y,
+    width,
+    height,
+    radius,
+    quality,
+    tostring(isBackdrop)
+  )
+end
+
+--- Get cached blurred canvas
+---@param key string Cache key
+---@return love.Canvas|nil canvas Cached canvas or nil
+function Cache.getBlurredCanvas(key)
+  local entry = Cache.blurredCanvases[key]
+  if entry then
+    entry.lastUsed = os.time()
+    return entry.canvas
+  end
+  return nil
+end
+
+--- Store blurred canvas in cache
+---@param key string Cache key
+---@param canvas love.Canvas Canvas to cache
+function Cache.setBlurredCanvas(key, canvas)
+  -- Limit cache size
+  local count = 0
+  for _ in pairs(Cache.blurredCanvases) do
+    count = count + 1
+  end
+
+  if count >= Cache.MAX_BLURRED_CANVAS_CACHE then
+    -- Remove oldest entry
+    local oldestKey = nil
+    local oldestTime = math.huge
+    for k, v in pairs(Cache.blurredCanvases) do
+      if v.lastUsed < oldestTime then
+        oldestTime = v.lastUsed
+        oldestKey = k
+      end
+    end
+
+    if oldestKey then
+      if Cache.blurredCanvases[oldestKey].canvas then
+        Cache.blurredCanvases[oldestKey].canvas:release()
+      end
+      Cache.blurredCanvases[oldestKey] = nil
+    end
+  end
+
+  Cache.blurredCanvases[key] = {
+    canvas = canvas,
+    lastUsed = os.time(),
+  }
+end
+
+--- Clear blurred canvas cache for specific element
+---@param elementId string Element ID to clear cache for
+function Cache.clearBlurredCanvasesForElement(elementId)
+  for key, entry in pairs(Cache.blurredCanvases) do
+    if key:match("^" .. elementId .. ":") then
+      if entry.canvas then
+        entry.canvas:release()
+      end
+      Cache.blurredCanvases[key] = nil
+    end
+  end
+end
+
+--- Clear all caches
+function Cache.clear()
+  -- Release all blurred canvases
+  for _, entry in pairs(Cache.blurredCanvases) do
+    if entry.canvas then
+      entry.canvas:release()
+    end
+  end
+
+  Cache.canvases = {}
+  Cache.quads = {}
+  Cache.blurInstances = {}
+  Cache.blurredCanvases = {}
+  warningCache = {} -- Clear warning cache on cache clear
+end
+
+-- ============================================================================
+-- SHADER BUILDER
+-- ============================================================================
+
+local ShaderBuilder = {}
+
+--- Build Gaussian blur shader with given parameters
+---@param taps number Number of samples (must be odd, >= 3)
+---@param offset number Offset value
+---@param offsetType string "weighted" or "center"
+---@param sigma number Sigma value for Gaussian distribution
+---@return love.Shader shader The compiled blur shader
+function ShaderBuilder.build(taps, offset, offsetType, sigma)
+  taps = math.floor(taps)
+  sigma = sigma >= 1 and sigma or (taps - 1) * offset / 6
+  sigma = math.max(sigma, 1)
+
+  local steps = (taps + 1) / 2
+
+  local gOffsets = {}
+  local gWeights = {}
+  for i = 1, steps do
+    gOffsets[i] = offset * (i - 1)
+    gWeights[i] = math.exp(-0.5 * (gOffsets[i] - 0) ^ 2 * 1 / sigma ^ 2)
+  end
+
+  local offsets = {}
+  local weights = {}
+  for i = #gWeights, 2, -2 do
+    local oA, oB = gOffsets[i], gOffsets[i - 1]
+    local wA, wB = gWeights[i], gWeights[i - 1]
+    wB = oB == 0 and wB / 2 or wB
+    local weight = wA + wB
+    offsets[#offsets + 1] = offsetType == "center" and (oA + oB) / 2 or (oA * wA + oB * wB) / weight
+    weights[#weights + 1] = weight
+  end
+
+  local code = {
+    [[
+    extern vec2 direction;
+    vec4 effect(vec4 color, Image tex, vec2 tc, vec2 sc) {]],
+  }
+
+  local norm = 0
+  if #gWeights % 2 == 0 then
+    code[#code + 1] = "vec4 c = vec4( 0.0 );"
+  else
+    local weight = gWeights[1]
+    norm = norm + weight
+    code[#code + 1] = string.format("vec4 c = %f * texture2D(tex, tc);", weight)
+  end
+
+  local template = "c += %f * ( texture2D(tex, tc + %f * direction)+ texture2D(tex, tc - %f * direction));\n"
+  for i = 1, #offsets do
+    local offset = offsets[i]
+    local weight = weights[i]
+    norm = norm + weight * 2
+    code[#code + 1] = string.format(template, weight, offset, offset)
+  end
+  code[#code + 1] = string.format("return c * vec4(%f) * color; }", 1 / norm)
+
+  local shaderCode = table.concat(code)
+  return love.graphics.newShader(shaderCode)
+end
+
+--- Get or create a blur instance from cache
+---@param quality number Quality level (1-10)
+---@return table blurData Cached blur data {shader, taps}
+function Cache.getBlurInstance(quality)
+  if not Cache.blurInstances[quality] then
+    local taps = 3 + (quality - 1) * 1.5
+    taps = math.floor(taps)
+    if taps % 2 == 0 then
+      taps = taps + 1
+    end
+
+    local shader = ShaderBuilder.build(taps, 1.0, "weighted", -1)
+    Cache.blurInstances[quality] = {
+      shader = shader,
+      taps = taps,
+    }
+  end
+
+  return Cache.blurInstances[quality]
+end
+
+---@class BlurProps
+---@field quality number? Quality level (1-10, default: 5)
+
+---@class Blur
+---@field shader love.Shader The blur shader
+---@field quality number Quality level (1-10)
+---@field taps number Number of shader taps
+---@field _ErrorHandler table? Reference to ErrorHandler module
+local Blur = {}
+Blur.__index = Blur
+
+--- Check if we should warn about large blur area in immediate mode
+---@param elementId string|nil Element ID for caching warnings
+---@param width number Blur area width
+---@param height number Blur area height
+---@param blurType string "content" or "backdrop"
+local function checkLargeBlurWarning(elementId, width, height, blurType)
+  -- Skip if no ErrorHandler available
+  if not Blur._ErrorHandler then
+    return
+  end
+
+  -- Skip if not in immediate mode
+  if not Blur._blurOptimizations then
+    return
+  end
+
+  -- Calculate blur area
+  local area = width * height
+
+  -- Skip if area is below threshold
+  if area <= Cache.LARGE_BLUR_THRESHOLD then
+    return
+  end
+
+  -- Generate warning key (use elementId if available, otherwise use dimensions)
+  local warningKey = elementId or string.format("%dx%d:%s", width, height, blurType)
+
+  -- Skip if already warned for this element/area
+  if warningCache[warningKey] then
+    return
+  end
+
+  -- Mark as warned
+  warningCache[warningKey] = true
+
+  -- Issue warning
+  local message =
+    string.format("Large %s blur area detected (%dx%d = %d pixels) in immediate mode", blurType, width, height, area)
+
+  local suggestion =
+    "Consider using retained mode for this component to avoid recreating blur effects every frame. Large blur operations are expensive and can cause performance issues in immediate mode."
+
+  Blur._ErrorHandler:warn("Blur", "PERF_003", {
+    area = string.format("%.0fx%.0f", width or 0, height or 0),
+  })
+end
+
+--- Create a new blur effect instance
+---@param props BlurProps? Blur configuration
+---@return Blur blur The new blur instance
+function Blur.new(props)
+  props = props or {}
+
+  local quality = props.quality or 5
+  quality = math.max(1, math.min(10, quality))
+
+  -- Get cached blur instance for this quality level
+  local blurData = Cache.getBlurInstance(quality)
+
+  local self = setmetatable({}, Blur)
+  self.shader = blurData.shader
+  self.quality = quality
+  self.taps = blurData.taps
+
+  return self
+end
+
+--- Apply blur to a region of the screen
+---@param radius number Blur radius in pixels
+---@param x number X position
+---@param y number Y position
+---@param width number Width of region
+---@param height number Height of region
+---@param drawFunc function Function to draw content to be blurred
+function Blur:applyToRegion(radius, x, y, width, height, drawFunc)
+  if type(drawFunc) ~= "function" then
+    if Blur._ErrorHandler then
+      Blur._ErrorHandler:warn("Blur", "BLUR_001")
+    end
+    return
+  end
+
+  if radius <= 0 or width <= 0 or height <= 0 then
+    drawFunc()
+    return
+  end
+
+  -- Early exit for very low radius (optimization)
+  if radius < Cache.RADIUS_THRESHOLD then
+    drawFunc()
+    return
+  end
+
+  -- Check for large blur area in immediate mode
+  checkLargeBlurWarning(nil, width, height, "content")
+
+  -- Calculate offset multiplier based on radius and quality
+  -- Higher quality = more samples = smaller steps for same radius
+  local offsetMultiplier = radius / self.quality
+
+  local canvas1 = Cache.getCanvas(width, height)
+  local canvas2 = Cache.getCanvas(width, height)
+
+  local prevCanvas = love.graphics.getCanvas()
+  local prevShader = love.graphics.getShader()
+  local prevColor = { love.graphics.getColor() }
+  local prevBlendMode = love.graphics.getBlendMode()
+
+  love.graphics.setCanvas(canvas1)
+  love.graphics.clear()
+  love.graphics.push()
+  love.graphics.origin()
+  love.graphics.translate(-x, -y)
+  drawFunc()
+  love.graphics.pop()
+
+  love.graphics.setShader(self.shader)
+  love.graphics.setColor(1, 1, 1, 1)
+  love.graphics.setBlendMode("alpha", "premultiplied")
+
+  -- Single pass with radius-controlled offset
+  love.graphics.setCanvas(canvas2)
+  love.graphics.clear()
+  self.shader:send("direction", { offsetMultiplier / width, 0 })
+  love.graphics.draw(canvas1, 0, 0)
+
+  love.graphics.setCanvas(canvas1)
+  love.graphics.clear()
+  self.shader:send("direction", { 0, offsetMultiplier / height })
+  love.graphics.draw(canvas2, 0, 0)
+
+  love.graphics.setCanvas(prevCanvas)
+  love.graphics.setShader()
+  love.graphics.setBlendMode(prevBlendMode)
+  love.graphics.draw(canvas1, x, y)
+
+  love.graphics.setShader(prevShader)
+  love.graphics.setColor(unpack(prevColor))
+
+  Cache.releaseCanvas(canvas1)
+  Cache.releaseCanvas(canvas2)
+end
+
+--- Apply backdrop blur effect (blur content behind a region)
+---@param radius number Blur radius in pixels
+---@param x number X position
+---@param y number Y position
+---@param width number Width of region
+---@param height number Height of region
+---@param backdropCanvas love.Canvas Canvas containing the backdrop content
+function Blur:applyBackdrop(radius, x, y, width, height, backdropCanvas)
+  if not backdropCanvas then
+    if Blur._ErrorHandler then
+      Blur._ErrorHandler:warn("Blur", "BLUR_002")
+    end
+    return
+  end
+
+  if radius <= 0 or width <= 0 or height <= 0 then
+    return
+  end
+
+  -- Early exit for very low radius (optimization)
+  if radius < Cache.RADIUS_THRESHOLD then
+    return
+  end
+
+  -- Calculate offset multiplier based on radius and quality
+  local offsetMultiplier = radius / self.quality
+
+  local canvas1 = Cache.getCanvas(width, height)
+  local canvas2 = Cache.getCanvas(width, height)
+
+  local prevCanvas = love.graphics.getCanvas()
+  local prevShader = love.graphics.getShader()
+  local prevColor = { love.graphics.getColor() }
+  local prevBlendMode = love.graphics.getBlendMode()
+
+  love.graphics.setCanvas(canvas1)
+  love.graphics.clear()
+  love.graphics.setColor(1, 1, 1, 1)
+  love.graphics.setBlendMode("alpha", "premultiplied")
+
+  local backdropWidth, backdropHeight = backdropCanvas:getDimensions()
+  local quad = Cache.getQuad(x, y, width, height, backdropWidth, backdropHeight)
+  love.graphics.draw(backdropCanvas, quad, 0, 0)
+
+  love.graphics.setShader(self.shader)
+
+  -- Single pass with radius-controlled offset
+  love.graphics.setCanvas(canvas2)
+  love.graphics.clear()
+  self.shader:send("direction", { offsetMultiplier / width, 0 })
+  love.graphics.draw(canvas1, 0, 0)
+
+  love.graphics.setCanvas(canvas1)
+  love.graphics.clear()
+  self.shader:send("direction", { 0, offsetMultiplier / height })
+  love.graphics.draw(canvas2, 0, 0)
+
+  love.graphics.setCanvas(prevCanvas)
+  love.graphics.setShader()
+  love.graphics.setBlendMode(prevBlendMode)
+  love.graphics.draw(canvas1, x, y)
+
+  love.graphics.setShader(prevShader)
+  love.graphics.setColor(unpack(prevColor))
+
+  Cache.releaseCanvas(canvas1)
+  Cache.releaseCanvas(canvas2)
+  Cache.releaseQuad(quad)
+end
+
+--- Get the current quality level
+---@return number quality Quality level (1-10)
+function Blur:getQuality()
+  return self.quality
+end
+
+--- Get the number of shader taps
+---@return number taps Number of shader taps
+function Blur:getTaps()
+  return self.taps
+end
+
+--- Clear all caches (call on window resize or memory cleanup)
+function Blur.clearCache()
+  Cache.clear()
+end
+
+--- Apply backdrop blur with caching support
+---@param radius number Blur radius in pixels
+---@param x number X position
+---@param y number Y position
+---@param width number Width of region
+---@param height number Height of region
+---@param backdropCanvas love.Canvas Canvas containing the backdrop content
+---@param elementId string|nil Element ID for caching (nil disables caching)
+function Blur:applyBackdropCached(radius, x, y, width, height, backdropCanvas, elementId)
+  -- If caching is disabled or no element ID, fall back to regular apply
+  if not Blur._blurOptimizations or not elementId then
+    return self:applyBackdrop(radius, x, y, width, height, backdropCanvas)
+  end
+
+  -- Generate cache key
+  local cacheKey = Cache.generateBlurCacheKey(elementId, x, y, width, height, radius, self.quality, true)
+
+  -- Check cache
+  local cachedCanvas = Cache.getBlurredCanvas(cacheKey)
+  if cachedCanvas then
+    -- Draw cached blur
+    local prevCanvas = love.graphics.getCanvas()
+    local prevShader = love.graphics.getShader()
+    local prevColor = { love.graphics.getColor() }
+    local prevBlendMode = love.graphics.getBlendMode()
+
+    love.graphics.setCanvas(prevCanvas)
+    love.graphics.setShader()
+    love.graphics.setBlendMode(prevBlendMode)
+    love.graphics.draw(cachedCanvas, x, y)
+
+    love.graphics.setShader(prevShader)
+    love.graphics.setColor(unpack(prevColor))
+    return
+  end
+
+  -- Not cached, render and cache
+  if not backdropCanvas then
+    if Blur._ErrorHandler then
+      Blur._ErrorHandler:warn("Blur", "BLUR_002")
+    end
+    return
+  end
+
+  if radius <= 0 or width <= 0 or height <= 0 then
+    return
+  end
+
+  -- Early exit for very low radius (optimization)
+  if radius < Cache.RADIUS_THRESHOLD then
+    return
+  end
+
+  -- Check for large blur area in immediate mode
+  checkLargeBlurWarning(elementId, width, height, "backdrop")
+
+  -- Calculate offset multiplier based on radius and quality
+  local offsetMultiplier = radius / self.quality
+
+  local canvas1 = Cache.getCanvas(width, height)
+  local canvas2 = Cache.getCanvas(width, height)
+
+  local prevCanvas = love.graphics.getCanvas()
+  local prevShader = love.graphics.getShader()
+  local prevColor = { love.graphics.getColor() }
+  local prevBlendMode = love.graphics.getBlendMode()
+
+  love.graphics.setCanvas(canvas1)
+  love.graphics.clear()
+  love.graphics.setColor(1, 1, 1, 1)
+  love.graphics.setBlendMode("alpha", "premultiplied")
+
+  local backdropWidth, backdropHeight = backdropCanvas:getDimensions()
+  local quad = Cache.getQuad(x, y, width, height, backdropWidth, backdropHeight)
+  love.graphics.draw(backdropCanvas, quad, 0, 0)
+
+  love.graphics.setShader(self.shader)
+
+  -- Single pass with radius-controlled offset
+  love.graphics.setCanvas(canvas2)
+  love.graphics.clear()
+  self.shader:send("direction", { offsetMultiplier / width, 0 })
+  love.graphics.draw(canvas1, 0, 0)
+
+  love.graphics.setCanvas(canvas1)
+  love.graphics.clear()
+  self.shader:send("direction", { 0, offsetMultiplier / height })
+  love.graphics.draw(canvas2, 0, 0)
+
+  -- Cache the result
+  local cachedResult = love.graphics.newCanvas(width, height)
+  love.graphics.setCanvas(cachedResult)
+  love.graphics.clear()
+  love.graphics.setShader()
+  love.graphics.setBlendMode("alpha", "premultiplied")
+  love.graphics.draw(canvas1, 0, 0)
+  Cache.setBlurredCanvas(cacheKey, cachedResult)
+
+  love.graphics.setCanvas(prevCanvas)
+  love.graphics.setShader()
+  love.graphics.setBlendMode(prevBlendMode)
+  love.graphics.draw(canvas1, x, y)
+
+  love.graphics.setShader(prevShader)
+  love.graphics.setColor(unpack(prevColor))
+
+  Cache.releaseCanvas(canvas1)
+  Cache.releaseCanvas(canvas2)
+  Cache.releaseQuad(quad)
+end
+
+--- Clear blur cache for specific element
+---@param elementId string Element ID
+function Blur.clearElementCache(elementId)
+  Cache.clearBlurredCanvasesForElement(elementId)
+end
+
+--- Initialize Blur module with dependencies
+---@param deps table Dependencies: { ErrorHandler = ErrorHandler?, immediateModeOptimizations = boolean? }
+function Blur.init(deps)
+  if type(deps) == "table" then
+    Blur._ErrorHandler = deps.ErrorHandler
+    Blur._blurOptimizations = deps.immediateModeOptimizations or false
+  end
+end
+
+Blur.Cache = Cache
+Blur.ShaderBuilder = ShaderBuilder
+
+return Blur

libs/flexlove/modules/Calc.lua

@@ -0,0 +1,385 @@
+--- Utility module for parsing and evaluating CSS-like calc() expressions
+--- Supports arithmetic operations (+, -, *, /) with mixed units (px, %, vw, vh)
+---@class Calc
+local Calc = {}
+
+--- Initialize Calc module with dependencies
+---@param deps CalcDependencies Dependencies: { ErrorHandler = ErrorHandler? }
+function Calc.init(deps)
+  Calc._ErrorHandler = deps.ErrorHandler
+end
+
+--- Token types for lexical analysis
+local TokenType = {
+  NUMBER = "NUMBER",
+  UNIT = "UNIT",
+  PLUS = "PLUS",
+  MINUS = "MINUS",
+  MULTIPLY = "MULTIPLY",
+  DIVIDE = "DIVIDE",
+  LPAREN = "LPAREN",
+  RPAREN = "RPAREN",
+  EOF = "EOF",
+}
+
+--- Tokenize a calc expression string into tokens
+---@param expr string The expression to tokenize (e.g., "50% - 10vw")
+---@return CalcToken[]? tokens Array of tokens with type, value, unit
+---@return string? error Error message if tokenization fails
+local function tokenize(expr)
+  local tokens = {}
+  local i = 1
+  local len = #expr
+
+  while i <= len do
+    local char = expr:sub(i, i)
+
+    -- Skip whitespace
+    if char:match("%s") then
+      i = i + 1
+    -- Number (including decimals, but NOT negative - handled separately below)
+    elseif char:match("%d") or (char == "." and expr:sub(i + 1, i + 1):match("%d")) then
+      local numStr = ""
+
+      -- Parse integer and decimal parts
+      while i <= len and (expr:sub(i, i):match("%d") or expr:sub(i, i) == ".") do
+        numStr = numStr .. expr:sub(i, i)
+        i = i + 1
+      end
+
+      local num = tonumber(numStr)
+      if not num then
+        return nil, "Invalid number: " .. numStr
+      end
+
+      -- Check for unit following the number
+      local unitStr = ""
+      while i <= len and expr:sub(i, i):match("[%a%%]") do
+        unitStr = unitStr .. expr:sub(i, i)
+        i = i + 1
+      end
+
+      -- Default to px if no unit
+      if unitStr == "" then
+        unitStr = "px"
+      end
+
+      -- Validate unit
+      local validUnits = { px = true, ["%"] = true, vw = true, vh = true }
+      if not validUnits[unitStr] then
+        return nil, "Invalid unit: " .. unitStr
+      end
+
+      table.insert(tokens, {
+        type = TokenType.NUMBER,
+        value = num,
+        unit = unitStr,
+      })
+    -- Operators
+    elseif char == "+" then
+      table.insert(tokens, { type = TokenType.PLUS })
+      i = i + 1
+    elseif char == "-" then
+      -- Check if this is a negative number or subtraction
+      -- It's a negative number if previous token is an operator or opening paren
+      local prevToken = tokens[#tokens]
+      if
+        not prevToken
+        or prevToken.type == TokenType.PLUS
+        or prevToken.type == TokenType.MINUS
+        or prevToken.type == TokenType.MULTIPLY
+        or prevToken.type == TokenType.DIVIDE
+        or prevToken.type == TokenType.LPAREN
+      then
+        -- This is a negative number, continue to number parsing
+        local numStr = "-"
+        i = i + 1
+
+        -- Parse integer and decimal parts
+        while i <= len and (expr:sub(i, i):match("%d") or expr:sub(i, i) == ".") do
+          numStr = numStr .. expr:sub(i, i)
+          i = i + 1
+        end
+
+        local num = tonumber(numStr)
+        if not num then
+          return nil, "Invalid number: " .. numStr
+        end
+
+        -- Check for unit following the number
+        local unitStr = ""
+        while i <= len and expr:sub(i, i):match("[%a%%]") do
+          unitStr = unitStr .. expr:sub(i, i)
+          i = i + 1
+        end
+
+        -- Default to px if no unit
+        if unitStr == "" then
+          unitStr = "px"
+        end
+
+        -- Validate unit
+        local validUnits = { px = true, ["%"] = true, vw = true, vh = true }
+        if not validUnits[unitStr] then
+          return nil, "Invalid unit: " .. unitStr
+        end
+
+        table.insert(tokens, {
+          type = TokenType.NUMBER,
+          value = num,
+          unit = unitStr,
+        })
+      else
+        -- This is subtraction operator
+        table.insert(tokens, { type = TokenType.MINUS })
+        i = i + 1
+      end
+    elseif char == "*" then
+      table.insert(tokens, { type = TokenType.MULTIPLY })
+      i = i + 1
+    elseif char == "/" then
+      table.insert(tokens, { type = TokenType.DIVIDE })
+      i = i + 1
+    elseif char == "(" then
+      table.insert(tokens, { type = TokenType.LPAREN })
+      i = i + 1
+    elseif char == ")" then
+      table.insert(tokens, { type = TokenType.RPAREN })
+      i = i + 1
+    else
+      return nil, "Unexpected character: " .. char
+    end
+  end
+
+  table.insert(tokens, { type = TokenType.EOF })
+  return tokens
+end
+
+--- Parser for calc expressions using recursive descent
+---@class Parser
+---@field tokens CalcToken[] Array of tokens
+---@field pos number Current token position
+local Parser = {}
+Parser.__index = Parser
+
+--- Create a new parser
+---@param tokens CalcToken[] Array of tokens
+---@return Parser
+function Parser.new(tokens)
+  local self = setmetatable({}, Parser)
+  self.tokens = tokens
+  self.pos = 1
+  return self
+end
+
+--- Get current token
+---@return CalcToken token Current token
+function Parser:current()
+  return self.tokens[self.pos]
+end
+
+--- Advance to next token
+function Parser:advance()
+  self.pos = self.pos + 1
+end
+
+--- Parse expression (handles + and -)
+---@return CalcASTNode ast Abstract syntax tree node
+function Parser:parseExpression()
+  local left = self:parseTerm()
+
+  while self:current().type == TokenType.PLUS or self:current().type == TokenType.MINUS do
+    local op = self:current().type
+    self:advance()
+    local right = self:parseTerm()
+    left = {
+      type = op == TokenType.PLUS and "add" or "subtract",
+      left = left,
+      right = right,
+    }
+  end
+
+  return left
+end
+
+--- Parse term (handles * and /)
+---@return CalcASTNode ast Abstract syntax tree node
+function Parser:parseTerm()
+  local left = self:parseFactor()
+
+  while self:current().type == TokenType.MULTIPLY or self:current().type == TokenType.DIVIDE do
+    local op = self:current().type
+    self:advance()
+    local right = self:parseFactor()
+    left = {
+      type = op == TokenType.MULTIPLY and "multiply" or "divide",
+      left = left,
+      right = right,
+    }
+  end
+
+  return left
+end
+
+--- Parse factor (handles numbers and parentheses)
+---@return CalcASTNode ast Abstract syntax tree node
+function Parser:parseFactor()
+  local token = self:current()
+
+  if token.type == TokenType.NUMBER then
+    self:advance()
+    return {
+      type = "number",
+      value = token.value,
+      unit = token.unit,
+    }
+  elseif token.type == TokenType.LPAREN then
+    self:advance()
+    local expr = self:parseExpression()
+    if self:current().type ~= TokenType.RPAREN then
+      error("Expected closing parenthesis")
+    end
+    self:advance()
+    return expr
+  else
+    error("Unexpected token: " .. token.type)
+  end
+end
+
+--- Parse the tokens into an AST
+---@return CalcASTNode ast Abstract syntax tree
+function Parser:parse()
+  local ast = self:parseExpression()
+  if self:current().type ~= TokenType.EOF then
+    error("Unexpected tokens after expression")
+  end
+  return ast
+end
+
+--- Create a calc expression object that can be resolved later
+--- This is the main API function that users call
+---@param expr string The calc expression (e.g., "50% - 10vw")
+---@return CalcObject calcObject A calc expression object with AST
+function Calc.new(expr)
+  -- Tokenize
+  local tokens, err = tokenize(expr)
+  if not tokens then
+    if Calc._ErrorHandler then
+      Calc._ErrorHandler:warn("Calc", "VAL_006", {
+        expression = expr,
+        error = err,
+      })
+    end
+    -- Return a fallback calc object that resolves to 0
+    return {
+      _isCalc = true,
+      _expr = expr,
+      _ast = nil,
+      _error = err,
+    }
+  end
+
+  -- Parse
+  local parser = Parser.new(tokens)
+  local success, ast = pcall(function()
+    return parser:parse()
+  end)
+
+  if not success then
+    if Calc._ErrorHandler then
+      Calc._ErrorHandler:warn("Calc", "VAL_006", {
+        expression = expr,
+        error = ast, -- ast contains error message on failure
+      })
+    end
+    -- Return a fallback calc object that resolves to 0
+    return {
+      _isCalc = true,
+      _expr = expr,
+      _ast = nil,
+      _error = ast,
+    }
+  end
+
+  return {
+    _isCalc = true,
+    _expr = expr,
+    _ast = ast,
+  }
+end
+
+--- Check if a value is a calc expression
+---@param value any The value to check
+---@return boolean isCalc True if value is a calc expression
+function Calc.isCalc(value)
+  return type(value) == "table" and value._isCalc == true
+end
+
+--- Resolve a calc expression to pixel value
+---@param calcObj CalcObject The calc expression object
+---@param viewportWidth number Viewport width in pixels
+---@param viewportHeight number Viewport height in pixels
+---@param parentSize number? Parent dimension for percentage units
+---@return number resolvedValue Resolved pixel value
+function Calc.resolve(calcObj, viewportWidth, viewportHeight, parentSize)
+  if not calcObj._ast then
+    -- Error during parsing, return 0
+    return 0
+  end
+
+  --- Evaluate AST node recursively
+  ---@param node table AST node
+  ---@return number value Evaluated value in pixels
+  local function evaluate(node)
+    if node.type == "number" then
+      -- Convert unit to pixels
+      local value = node.value
+      local unit = node.unit
+
+      if unit == "px" then
+        return value
+      elseif unit == "%" then
+        if not parentSize then
+          if Calc._ErrorHandler then
+            Calc._ErrorHandler:warn("Calc", "LAY_003", {
+              unit = "%",
+              issue = "parent dimension not available",
+            })
+          end
+          return 0
+        end
+        return (value / 100) * parentSize
+      elseif unit == "vw" then
+        return (value / 100) * viewportWidth
+      elseif unit == "vh" then
+        return (value / 100) * viewportHeight
+      else
+        return 0
+      end
+    elseif node.type == "add" then
+      return evaluate(node.left) + evaluate(node.right)
+    elseif node.type == "subtract" then
+      return evaluate(node.left) - evaluate(node.right)
+    elseif node.type == "multiply" then
+      return evaluate(node.left) * evaluate(node.right)
+    elseif node.type == "divide" then
+      local divisor = evaluate(node.right)
+      if divisor == 0 then
+        if Calc._ErrorHandler then
+          Calc._ErrorHandler:warn("Calc", "VAL_006", {
+            expression = calcObj._expr,
+            error = "Division by zero",
+          })
+        end
+        return 0
+      end
+      return evaluate(node.left) / divisor
+    else
+      return 0
+    end
+  end
+
+  return evaluate(calcObj._ast)
+end
+
+return Calc

libs/flexlove/modules/Color.lua

@@ -0,0 +1,346 @@
+---@class Color
+local Color = {}
+Color.__index = Color
+
+--- Initialize module with shared dependencies
+---@param deps table Dependencies {ErrorHandler}
+function Color.init(deps)
+  if type(deps) == "table" then
+    Color._ErrorHandler = deps.ErrorHandler
+  end
+end
+
+--- Build type-safe color objects with automatic validation and clamping
+--- Use this to avoid invalid color values and ensure consistent LÖVE-compatible colors (0-1 range)
+---@param r number? Red component (0-1), defaults to 0
+---@param g number? Green component (0-1), defaults to 0
+---@param b number? Blue component (0-1), defaults to 0
+---@param a number? Alpha component (0-1), defaults to 1
+---@return Color color The new color instance
+function Color.new(r, g, b, a)
+  -- Sanitize and clamp color components
+  local _, sanitizedR = Color.validateColorChannel(r or 0, 1)
+  local _, sanitizedG = Color.validateColorChannel(g or 0, 1)
+  local _, sanitizedB = Color.validateColorChannel(b or 0, 1)
+  local _, sanitizedA = Color.validateColorChannel(a or 1, 1)
+
+  -- FFI structs don't support metatables/methods without wrapping
+  -- The wrapping overhead negates the FFI benefits
+  local self = setmetatable({}, Color)
+  self.r = sanitizedR or 0
+  self.g = sanitizedG or 0
+  self.b = sanitizedB or 0
+  self.a = sanitizedA or 1
+  return self
+end
+
+--- Extract individual color channels for use with love.graphics.setColor()
+--- Use this to pass colors to LÖVE's rendering functions
+---@return number r Red component (0-1)
+---@return number g Green component (0-1)
+---@return number b Blue component (0-1)
+---@return number a Alpha component (0-1)
+function Color:toRGBA()
+  return self.r, self.g, self.b, self.a
+end
+
+--- Parse CSS-style hex colors into Color objects for designer-friendly workflows
+--- Use this to work with colors from design tools that export hex values
+---@param hexWithTag string Hex color string (e.g. "#RRGGBB" or "#RRGGBBAA")
+---@return Color color The parsed color (returns white on error with warning)
+function Color.fromHex(hexWithTag)
+  -- Validate input type
+  if type(hexWithTag) ~= "string" then
+    Color._ErrorHandler:warn("Color", "VAL_004", {
+      input = tostring(hexWithTag),
+      issue = "not a string",
+      fallback = "white (#FFFFFF)",
+    })
+    return Color.new(1, 1, 1, 1)
+  end
+
+  local hex = hexWithTag:gsub("#", "")
+  if #hex == 6 then
+    local r = tonumber("0x" .. hex:sub(1, 2))
+    local g = tonumber("0x" .. hex:sub(3, 4))
+    local b = tonumber("0x" .. hex:sub(5, 6))
+    if not r or not g or not b then
+      Color._ErrorHandler:warn("Color", "VAL_004", {
+        input = hexWithTag,
+        issue = "invalid hex digits",
+        fallback = "white (#FFFFFF)",
+      })
+      return Color.new(1, 1, 1, 1) -- Return white as fallback
+    end
+    return Color.new(r / 255, g / 255, b / 255, 1)
+  elseif #hex == 8 then
+    local r = tonumber("0x" .. hex:sub(1, 2))
+    local g = tonumber("0x" .. hex:sub(3, 4))
+    local b = tonumber("0x" .. hex:sub(5, 6))
+    local a = tonumber("0x" .. hex:sub(7, 8))
+    if not r or not g or not b or not a then
+      Color._ErrorHandler:warn("Color", "VAL_004", {
+        input = hexWithTag,
+        issue = "invalid hex digits",
+        fallback = "white (#FFFFFFFF)",
+      })
+      return Color.new(1, 1, 1, 1) -- Return white as fallback
+    end
+    return Color.new(r / 255, g / 255, b / 255, a / 255)
+  else
+    Color._ErrorHandler:warn("Color", "VAL_004", {
+      input = hexWithTag,
+      expected = "#RRGGBB or #RRGGBBAA",
+      hexLength = #hex,
+      fallback = "white (#FFFFFF)",
+    })
+    return Color.new(1, 1, 1, 1) -- Return white as fallback
+  end
+end
+
+--- Verify and sanitize individual color components to prevent rendering errors
+--- Use this to safely process user input or external color data
+---@param value any Value to validate
+---@param max number? Maximum value (255 for 0-255 range, 1 for 0-1 range), defaults to 1
+---@return boolean valid True if valid
+---@return number? clamped Clamped value in 0-1 range, nil if invalid
+function Color.validateColorChannel(value, max)
+  max = max or 1
+
+  if type(value) ~= "number" then
+    return false, nil
+  end
+
+  -- Check for NaN
+  if value ~= value then
+    return false, nil
+  end
+
+  -- Check for Infinity
+  if value == math.huge or value == -math.huge then
+    return false, nil
+  end
+
+  -- Normalize to 0-1 range
+  local normalized = value
+  if max == 255 then
+    normalized = value / 255
+  end
+
+  -- Clamp to valid range
+  normalized = math.max(0, math.min(1, normalized))
+
+  return true, normalized
+end
+
+--- Validate hex color format
+---@param hex string Hex color string (with or without #)
+---@return boolean valid True if valid format
+---@return string? error Error message if invalid, nil if valid
+function Color.validateHexColor(hex)
+  if type(hex) ~= "string" then
+    return false, "Hex color must be a string"
+  end
+
+  -- Remove # prefix
+  local cleanHex = hex:gsub("^#", "")
+
+  -- Check length (3, 6, or 8 characters)
+  if #cleanHex ~= 3 and #cleanHex ~= 6 and #cleanHex ~= 8 then
+    return false, string.format("Invalid hex length: %d. Expected 3, 6, or 8 characters", #cleanHex)
+  end
+
+  -- Check for valid hex characters
+  if not cleanHex:match("^[0-9A-Fa-f]+$") then
+    return false, "Invalid hex characters. Use only 0-9, A-F"
+  end
+
+  return true, nil
+end
+
+--- Validate RGB/RGBA color values
+---@param r number Red component
+---@param g number Green component
+---@param b number Blue component
+---@param a number? Alpha component (optional, defaults to max)
+---@param max number? Maximum value (255 or 1), defaults to 1
+---@return boolean valid True if valid
+---@return string? error Error message if invalid, nil if valid
+function Color.validateRGBColor(r, g, b, a, max)
+  max = max or 1
+  a = a or max
+
+  local rValid = Color.validateColorChannel(r, max)
+  local gValid = Color.validateColorChannel(g, max)
+  local bValid = Color.validateColorChannel(b, max)
+  local aValid = Color.validateColorChannel(a, max)
+
+  if not rValid then
+    return false, string.format("Invalid red channel: %s", tostring(r))
+  end
+  if not gValid then
+    return false, string.format("Invalid green channel: %s", tostring(g))
+  end
+  if not bValid then
+    return false, string.format("Invalid blue channel: %s", tostring(b))
+  end
+  if not aValid then
+    return false, string.format("Invalid alpha channel: %s", tostring(a))
+  end
+
+  return true, nil
+end
+
+--- Check if a value is a valid color format
+---@param value any Value to check
+---@return string? format Format type ("hex", "named", "table"), nil if invalid
+function Color.isValidColorFormat(value)
+  local valueType = type(value)
+
+  -- Check for hex string
+  if valueType == "string" then
+    if value:match("^#?[0-9A-Fa-f]+$") then
+      local valid = Color.validateHexColor(value)
+      if valid then
+        return "hex"
+      end
+    end
+
+    return nil
+  end
+
+  -- Check for table format
+  if valueType == "table" then
+    -- Check for Color instance
+    if getmetatable(value) == Color then
+      return "table"
+    end
+
+    -- Check for array format {r, g, b, a}
+    if value[1] and value[2] and value[3] then
+      local valid = Color.validateRGBColor(value[1], value[2], value[3], value[4])
+      if valid then
+        return "table"
+      end
+    end
+
+    -- Check for named format {r=, g=, b=, a=}
+    if value.r and value.g and value.b then
+      local valid = Color.validateRGBColor(value.r, value.g, value.b, value.a)
+      if valid then
+        return "table"
+      end
+    end
+
+    return nil
+  end
+
+  return nil
+end
+
+--- Convert any color format to a valid Color object with graceful fallbacks
+--- Use this to robustly handle colors from any source without crashes
+---@param value any Color value to sanitize (hex, named, table, or Color instance)
+---@param default Color? Default color if invalid (defaults to black)
+---@return Color color Sanitized color instance (guaranteed non-nil)
+function Color.sanitizeColor(value, default)
+  default = default or Color.new(0, 0, 0, 1)
+
+  local format = Color.isValidColorFormat(value)
+
+  if not format then
+    return default
+  end
+
+  -- Handle hex format
+  if format == "hex" then
+    local cleanHex = value:gsub("^#", "")
+
+    -- Expand 3-digit hex to 6-digit
+    if #cleanHex == 3 then
+      cleanHex = cleanHex:gsub("(.)", "%1%1")
+    end
+
+    -- Try to parse
+    local success, result = pcall(Color.fromHex, "#" .. cleanHex)
+    if success then
+      return result
+    else
+      return default
+    end
+  end
+
+  if format == "table" then
+    -- Color instance
+    if getmetatable(value) == Color then
+      return value
+    end
+
+    -- Array format
+    if value[1] then
+      local _, r = Color.validateColorChannel(value[1], 1)
+      local _, g = Color.validateColorChannel(value[2], 1)
+      local _, b = Color.validateColorChannel(value[3], 1)
+      local _, a = Color.validateColorChannel(value[4] or 1, 1)
+
+      if r and g and b and a then
+        return Color.new(r, g, b, a)
+      end
+    end
+
+    -- Named format
+    if value.r then
+      local _, r = Color.validateColorChannel(value.r, 1)
+      local _, g = Color.validateColorChannel(value.g, 1)
+      local _, b = Color.validateColorChannel(value.b, 1)
+      local _, a = Color.validateColorChannel(value.a or 1, 1)
+
+      if r and g and b and a then
+        return Color.new(r, g, b, a)
+      end
+    end
+  end
+
+  return default
+end
+
+--- Universally convert any color format (hex, named, table) into a Color object
+--- Use this as your main color input handler to accept flexible color specifications
+---@param value any Color value (hex string, named color, table, or Color instance)
+---@return Color color Parsed color instance (defaults to black on error)
+function Color.parse(value)
+  return Color.sanitizeColor(value, Color.new(0, 0, 0, 1))
+end
+
+--- Smoothly transition between two colors for animations and gradients
+--- Use this to create color-based animations without manual channel calculations
+---@param colorA Color Starting color
+---@param colorB Color Ending color
+---@param t number Interpolation factor (0-1)
+---@return Color color Interpolated color
+function Color.lerp(colorA, colorB, t)
+  -- Sanitize inputs
+  if type(colorA) ~= "table" or getmetatable(colorA) ~= Color then
+    colorA = Color.new(0, 0, 0, 1)
+  end
+  if type(colorB) ~= "table" or getmetatable(colorB) ~= Color then
+    colorB = Color.new(0, 0, 0, 1)
+  end
+  if type(t) ~= "number" or t ~= t or t == math.huge or t == -math.huge then
+    t = 0
+  end
+
+  -- Clamp t to 0-1 range
+  t = math.max(0, math.min(1, t))
+
+  -- Linear interpolation for each channel
+  local oneMinusT = 1 - t
+  local r = colorA.r * oneMinusT + colorB.r * t
+  local g = colorA.g * oneMinusT + colorB.g * t
+  local b = colorA.b * oneMinusT + colorB.b * t
+  local a = colorA.a * oneMinusT + colorB.a * t
+
+  return Color.new(r, g, b, a)
+end
+
+return Color

libs/flexlove/modules/Context.lua

@@ -0,0 +1,596 @@
+---@class Context
+local modulePath = (...):match("(.-)[^%.]+$")
+local ZIndex = require(modulePath .. "ZIndex")
+local Element = require(modulePath .. "Element")
+local Context = {
+  topElements = {},
+  -- Base scale configuration
+  baseScale = nil, -- {width: number, height: number}
+  -- Current scale factors
+  scaleFactors = { x = 1.0, y = 1.0 },
+  defaultTheme = nil,
+  _focusedElement = nil,
+  _focusedElementId = nil, -- Stable id used to rehydrate focus across immediate-mode frames
+  _activeEventElement = nil,
+  _cachedViewport = { width = 0, height = 0 },
+  -- Immediate mode state
+  _immediateMode = false,
+  _frameNumber = 0,
+  _currentFrameElements = {},
+  _immediateModeState = nil, -- Will be initialized if immediate mode is enabled
+  _frameStarted = false,
+  _autoBeganFrame = false,
+  -- Z-index ordered element tracking for immediate mode
+  _zIndexOrderedElements = {}, -- Array of elements sorted by z-index (lowest to highest)
+  -- Focus management guard
+  _settingFocus = false,
+  -- Hook called whenever focus changes: function(element) or nil
+  _onFocusChanged = nil,
+
+  -- Navigation state
+  _navigationContext = {
+    lastFocusedElement = nil, -- For returning from modals
+    navigationMode = "sequential", -- "sequential" or "directional"
+    containerElement = nil, -- Current navigation container
+  },
+
+  initialized = false,
+
+  -- Expose internal hit-testing helpers for unit testing only.
+  -- These are populated below after their local definitions. They are NOT part
+  -- of the public API and must not be relied on by callers; they exist so the
+  -- shared hit-test core (the single place display:none guarding lives) can be
+  -- exercised directly by the test suite. Subsequent unified-event-routing
+  -- tasks consume these locals through the mode-agnostic query functions.
+  _test = {
+    pointHitsElement = nil,
+    elementHasScrollableOverflow = nil,
+  },
+
+  -- Debug draw overlay
+  _debugDraw = false,
+  _debugDrawKey = nil,
+
+  -- Initialization state tracking
+  ---@type "uninitialized"|"initializing"|"ready"
+  _initState = "uninitialized",
+  ---@type table[] Queue of {props: ElementProps, callback: function(element)|nil}
+  _initQueue = {},
+
+  -- Per-frame cache for findInteractiveAtPosition so Clickable.onUpdate's
+  -- per-element call (unified-event-routing task 05) doesn't re-walk the tree
+  -- + realloc + sort for every interactive element sharing the same cursor.
+  -- Invalidated explicitly by Context.clearInteractiveCache() at the start of
+  -- each flexlove.update (both modes) and in clearFrameElements (immediate
+  -- mid-frame rebuild). It also self-invalidates when the topElements table
+  -- reference changes (tests replace it per-case; immediate-mode beginFrame
+  -- reassigns it each frame), so direct callers that never go through
+  -- flexlove.update still see fresh results across tree swaps.
+  _interactiveLookupCache = {
+    valid = false,
+    x = nil,
+    y = nil,
+    result = nil,
+    topElementsRef = nil,
+    frameNumber = -1,
+  },
+}
+
+--- Check if a point hits an element, accounting for scroll offsets and display:none.
+--- All mode-agnostic query functions use this as their single hit-test entry point,
+--- ensuring fixes like display:none guarding apply everywhere.
+---
+--- This is the single canonical place where `element.display == false` short-
+--- circuits hit testing. Parent-chain clipping/scroll-offset accumulation is
+--- the caller's responsibility: callers walk the parent chain (using
+--- `elementHasScrollableOverflow` to decide which ancestors clip) and pass the
+--- accumulated scroll offset in here. Keeping the parent walk outside this core
+--- lets retained-mode (recursive tree descent) and immediate-mode (flat
+--- z-index list) callers share the exact same primitive bounds/display logic.
+---@param element Element
+---@param mx number Screen X coordinate
+---@param my number Screen Y coordinate
+---@param scrollOffsetX number? Accumulated scroll offset from parent chain
+---@param scrollOffsetY number? Accumulated scroll offset from parent chain
+---@return boolean hits
+local function pointHitsElement(element, mx, my, scrollOffsetX, scrollOffsetY)
+  scrollOffsetX = scrollOffsetX or 0
+  scrollOffsetY = scrollOffsetY or 0
+
+  -- Skip display:none elements entirely
+  if element.display == false then
+    return false
+  end
+
+  local bx = element.x
+  local by = element.y
+  local bw = element._borderBoxWidth or (element.width + element.padding.left + element.padding.right)
+  local bh = element._borderBoxHeight or (element.height + element.padding.top + element.padding.bottom)
+
+  local adjustedX = mx + scrollOffsetX
+  local adjustedY = my + scrollOffsetY
+
+  return adjustedX >= bx and adjustedX <= bx + bw and adjustedY >= by and adjustedY <= by + bh
+end
+
+--- Check if an element has scrollable/clipped overflow (for scroll offset accumulation).
+--- Returns true for `scroll`, `auto`, and `hidden` on either axis. These are the
+--- overflow values that clip/translate descendant content and therefore require
+--- scroll-offset compensation when hit testing descendants.
+---@param element Element
+---@return boolean
+local function elementHasScrollableOverflow(element)
+  local overflowX = element.overflowX or element.overflow
+  local overflowY = element.overflowY or element.overflow
+  return overflowX == "scroll"
+    or overflowX == "auto"
+    or overflowY == "scroll"
+    or overflowY == "auto"
+    or overflowX == "hidden"
+    or overflowY == "hidden"
+end
+
+-- Expose the two core helpers for unit testing only (see Context._test above).
+Context._test.pointHitsElement = pointHitsElement
+Context._test.elementHasScrollableOverflow = elementHasScrollableOverflow
+
+-- Public exposure of the canonical hit-test primitive so other modules
+-- (e.g. FlexLove's `getElementAtPosition` / `_getTouchElementAtPosition`
+-- tree walks) can share the single implementation of bounds + display:none
+-- guarding instead of duplicating the `display == false` check inline.
+-- This keeps "display == false" in exactly one place for hit-testing.
+Context.pointHitsElement = pointHitsElement
+Context.elementHasScrollableOverflow = elementHasScrollableOverflow
+
+--- Find the first scrollable element at a screen position, regardless of mode.
+--- This is the mode-agnostic successor to the two duplicated scrollable lookups
+--- that previously lived inline in `flexlove.wheelmoved`:
+---   * immediate mode — walked `Context._zIndexOrderedElements` in reverse and
+---     re-implemented bounds + parent-chain clipping + scroll-offset math; and
+---   * retained mode — recursed through `Context.topElements` with a private
+---     `findScrollableAtPosition(elements, x, y)` helper.
+--- Both paths now collapse into this single function, which routes every
+--- hit test through `pointHitsElement` (the single place `display == false`
+--- is guarded) and every scroll-offset decision through
+--- `elementHasScrollableOverflow`. As a result display:none elements are never
+--- returned in either mode, fixing the latent bug where the immediate-mode
+--- path's `isPointInElement` did not skip display:none elements.
+---
+--- The retained-mode branch intentionally mirrors the original
+--- `findScrollableAtPosition` helper's tree walk (deepest scrollable wins,
+--- children checked before self) but is upgraded to thread accumulated scroll
+--- offsets through `pointHitsElement` so nested scrolled containers are tested
+--- against their visible position. The original helper is removed once
+--- `flexlove.wheelmoved` is rerouted onto this function in task 04.
+---@param x number Screen X coordinate
+---@param y number Screen Y coordinate
+---@return Element|nil The scrollable element, or nil
+function Context.findScrollableAtPosition(x, y)
+  if Context.isImmediateMode() then
+    -- Immediate mode: iterate the z-index ordered list (reverse order =
+    -- topmost first). pointHitsElement supplies the bounds + display guard.
+    for i = #Context._zIndexOrderedElements, 1, -1 do
+      local element = Context._zIndexOrderedElements[i]
+      if pointHitsElement(element, x, y) then
+        local overflowX = element.overflowX or element.overflow
+        local overflowY = element.overflowY or element.overflow
+        if
+          (overflowX == "scroll" or overflowX == "auto" or overflowY == "scroll" or overflowY == "auto")
+          and (element._overflowX or element._overflowY)
+        then
+          return element
+        end
+      end
+    end
+    return nil
+  else
+    -- Retained mode: recursive tree walk from topElements. Children are
+    -- checked before self (deepest scrollable wins); accumulated scroll
+    -- offsets are threaded through pointHitsElement so descendants of
+    -- scrolled containers are hit-tested against their translated position.
+    local function findInTree(elements, scrollOffsetX, scrollOffsetY)
+      scrollOffsetX = scrollOffsetX or 0
+      scrollOffsetY = scrollOffsetY or 0
+      for i = #elements, 1, -1 do
+        local element = elements[i]
+        if pointHitsElement(element, x, y, scrollOffsetX, scrollOffsetY) then
+          if #element.children > 0 then
+            local childScrollOffsetX = scrollOffsetX
+            local childScrollOffsetY = scrollOffsetY
+            if elementHasScrollableOverflow(element) then
+              childScrollOffsetX = childScrollOffsetX + (element._scrollX or 0)
+              childScrollOffsetY = childScrollOffsetY + (element._scrollY or 0)
+            end
+            local childResult = findInTree(element.children, childScrollOffsetX, childScrollOffsetY)
+            if childResult then
+              return childResult
+            end
+          end
+          -- No descendant was scrollable — check self.
+          local overflowX = element.overflowX or element.overflow
+          local overflowY = element.overflowY or element.overflow
+          if
+            (overflowX == "scroll" or overflowX == "auto" or overflowY == "scroll" or overflowY == "auto")
+            and (element._overflowX or element._overflowY)
+          then
+            return element
+          end
+        end
+      end
+      return nil
+    end
+    return findInTree(Context.topElements)
+  end
+end
+
+--- Check whether immediate mode is active.
+--- This is the single canonical accessor for the mode flag consumed throughout
+--- the framework. Mode-aware branches elsewhere call this instead of reading
+--- `Context._immediateMode` directly, so the literal mode flag only appears
+--- here (its definition) and in StateManager (its mirrored storage) — never
+--- scattered across Element / behaviors / managers (behavior-mode-unification
+--- task 11).
+---@return boolean
+function Context.isImmediateMode()
+  return Context._immediateMode
+end
+
+---@return number, number -- scaleX, scaleY
+function Context.getScaleFactors()
+  return Context.scaleFactors.x, Context.scaleFactors.y
+end
+
+--- Register an element in the z-index ordered tree (for immediate mode)
+---@param element Element The element to register
+function Context.registerElement(element)
+  if not Context.isImmediateMode() then
+    return
+  end
+
+  table.insert(Context._zIndexOrderedElements, element)
+end
+
+function Context.clearFrameElements()
+  Context._zIndexOrderedElements = {}
+  Context.clearInteractiveCache()
+end
+
+--- Compute the composite z-index key for an element.
+--- rootZ * ROOT_WEIGHT + depth * DEPTH_WEIGHT + ownZ
+---
+--- ROOT_WEIGHT (10^10) gives the top-level ancestor's z-index 10 digits of significance.
+--- DEPTH_WEIGHT (10^3) gives nesting depth 3 digits, ensuring children always sort above
+--- their ancestors. The element's own z (capped to ±999 by ZIndex.clamp) fits within the
+--- remaining 3 digits without interfering with the depth component.
+---
+--- These weights assume |z| <= ZIndex.MAX_Z and practical tree depths (< 10^7), which
+--- keeps the composite key well within Lua's exact integer range (2^53 ≈ 9 × 10^15).
+---
+--- This is the SINGLE canonical z-index ordering function, used by both
+--- sortElementsByZIndex (the immediate-mode flat list sort) and
+--- findInteractiveAtPosition (the mode-agnostic occlusion sort). Keeping them
+--- on the same key ensures the interactive topmost element matches the visual
+--- draw order — a button in a z=50 MainMenu window must occlude a button in a
+--- z=0 BottomBar even when both buttons default to own z=0.
+local function getEffectiveZIndex(elem)
+  local ownZ = elem.z or 0
+  local rootZ = ownZ
+  local depth = 0
+  local current = elem.parent
+  while current do
+    rootZ = current.z or 0
+    depth = depth + 1
+    current = current.parent
+  end
+  return rootZ * ZIndex.ROOT_WEIGHT + depth * ZIndex.DEPTH_WEIGHT + ownZ
+end
+
+-- Public exposure so FlexLove.getElementAtPosition shares the single
+-- implementation instead of duplicating the parent-chain walk as a closure.
+Context.getEffectiveZIndex = getEffectiveZIndex
+
+--- Sort elements by z-index (called after all elements are registered)
+function Context.sortElementsByZIndex()
+  -- Precompute the composite key ONCE per element so the sort comparator is a
+  -- pure table lookup (O(1)) instead of re-walking the parent chain on every
+  -- O(N log N) comparison. This function runs every frame in immediate mode.
+  local elements = Context._zIndexOrderedElements
+  local zIndices = {}
+  for i = 1, #elements do
+    zIndices[elements[i]] = getEffectiveZIndex(elements[i])
+  end
+  table.sort(elements, function(a, b)
+    return zIndices[a] < zIndices[b]
+  end)
+end
+
+--- Find the topmost interactive element at a screen position, regardless of mode.
+--- Replaces the former immediate-mode-only `Context.getTopElementAt()` (removed
+--- in unified-event-routing task 05) and the retained-mode `_activeEventElement`
+--- mechanism — both are now funneled through this single entry point.
+---
+--- In immediate mode this replaces Context.getTopElementAt() (which only worked
+--- in immediate mode). In retained mode this provides the same role as the
+--- _activeEventElement set by flexlove.getElementAtPosition().
+---
+--- An element is "interactive" if it has an onEvent handler, themeComponent, or is editable.
+---@param x number Screen X coordinate
+---@param y number Screen Y coordinate
+---@return Element|nil The topmost interactive element, or nil
+function Context.findInteractiveAtPosition(x, y)
+  -- Per-frame cache: Clickable.onUpdate runs this for every interactive
+  -- element under the same cursor, but the result for a given (x,y) is
+  -- identical across all of them within a single update pass. Returning a
+  -- cached element restores the old 1x/frame cost of the _activeEventElement
+  -- mechanism that task 05 replaced. Cache auto-invalidates when the
+  -- topElements table reference changes (so tests and mid-frame rebuilds get
+  -- fresh results) and is cleared explicitly per-frame in flexlove.update.
+  local cache = Context._interactiveLookupCache
+  if
+    cache.valid
+    and cache.x == x
+    and cache.y == y
+    and cache.topElementsRef == Context.topElements
+    and cache.frameNumber == Context._frameNumber
+  then
+    return cache.result
+  end
+
+  local interactiveCandidates = {}
+
+  local function collectInteractive(element, scrollOffsetX, scrollOffsetY)
+    scrollOffsetX = scrollOffsetX or 0
+    scrollOffsetY = scrollOffsetY or 0
+
+    if not pointHitsElement(element, x, y, scrollOffsetX, scrollOffsetY) then
+      return
+    end
+
+    -- Check if this element is interactive
+    if element.onEvent or element.themeComponent or element.editable then
+      table.insert(interactiveCandidates, element)
+    end
+
+    -- Recurse into children with accumulated scroll offset
+    local childScrollOffsetX = scrollOffsetX
+    local childScrollOffsetY = scrollOffsetY
+    if elementHasScrollableOverflow(element) then
+      childScrollOffsetX = childScrollOffsetX + (element._scrollX or 0)
+      childScrollOffsetY = childScrollOffsetY + (element._scrollY or 0)
+    end
+
+    for _, child in ipairs(element.children) do
+      collectInteractive(child, childScrollOffsetX, childScrollOffsetY)
+    end
+  end
+
+  -- Always traverse the tree (works in both modes — topElements exists always)
+  for _, element in ipairs(Context.topElements) do
+    collectInteractive(element)
+  end
+
+  -- Sort by composite z-index descending — topmost wins. The composite key
+  -- (rootZ * ROOT_WEIGHT + depth * DEPTH_WEIGHT + ownZ) matches the ordering
+  -- used by sortElementsByZIndex / _zIndexOrderedElements, so the interactive
+  -- topmost element matches the visual draw order. This is critical for the
+  -- game's multi-window layout: a button inside a z=50 MainMenu window must
+  -- occlude a button inside a z=0 BottomBar even when both buttons default to
+  -- own z=0. Sorting by own-z alone (the original implementation) couldn't
+  -- distinguish them, so the wrong window's button could win, leaving the
+  -- visible button's isActiveElement=false and clicks/hover dead.
+  local zIndices = {}
+  for _, el in ipairs(interactiveCandidates) do
+    zIndices[el] = getEffectiveZIndex(el)
+  end
+  table.sort(interactiveCandidates, function(a, b)
+    return zIndices[a] > zIndices[b]
+  end)
+
+  local result = interactiveCandidates[1]
+
+  cache.x = x
+  cache.y = y
+  cache.result = result
+  cache.topElementsRef = Context.topElements
+  cache.frameNumber = Context._frameNumber
+  cache.valid = true
+
+  return result
+end
+
+--- Invalidate the per-frame `findInteractiveAtPosition` cache.
+--- Called once at the top of `flexlove.update` (the natural per-frame boundary
+--- in both modes) and from `clearFrameElements` (immediate-mode mid-frame
+--- rebuild). After invalidation the next lookup recomputes fresh.
+function Context.clearInteractiveCache()
+  local cache = Context._interactiveLookupCache
+  cache.valid = false
+  cache.x = nil
+  cache.y = nil
+  cache.result = nil
+  cache.topElementsRef = nil
+  cache.frameNumber = -1
+end
+
+--- Set the focused element (centralizes focus management)
+--- Automatically blurs the previously focused element if different
+---@param element Element|nil The element to focus (nil to clear focus)
+function Context.setFocused(element)
+  if Context._focusedElement == element then
+    return -- Already focused
+  end
+
+  -- Prevent re-entry during focus change
+  if Context._settingFocus then
+    return
+  end
+  Context._settingFocus = true
+
+  -- Save reference to previously focused element before updating
+  local oldFocusedElement = Context._focusedElement
+
+  -- Blur previously focused element
+  if oldFocusedElement and oldFocusedElement ~= element then
+    if oldFocusedElement._textEditor then
+      oldFocusedElement._textEditor:blur(oldFocusedElement)
+    end
+  end
+
+  -- Set new focused element and persist its id for immediate-mode rehydration
+  Context._focusedElement = element
+  Context._focusedElementId = element and (element.id ~= "" and element.id or nil) or nil
+
+  -- Notify any registered focus change hook (e.g. FocusIndicator)
+  if Context._onFocusChanged then
+    Context._onFocusChanged(element)
+  end
+
+  -- Focus the new element's text editor if it has one
+  if element and element._textEditor then
+    element._textEditor._focused = true
+  end
+
+  Context._settingFocus = false
+end
+
+--- Recursively search for an element by id in an element tree
+---@param root Element The root element to start searching from
+---@param targetId string The id to search for
+---@return Element|nil The element with the matching id, or nil if not found
+local function findElementById(root, targetId)
+  if root.id == targetId then
+    return root
+  end
+  for _, child in ipairs(root.children or {}) do
+    local found = findElementById(child, targetId)
+    if found then
+      return found
+    end
+  end
+  return nil
+end
+
+--- Rehydrate _focusedElement from _focusedElementId by scanning live elements.
+--- Called at the start of getFocused() in immediate mode so stale references
+--- are always replaced with the current-frame object before use.
+function Context._rehydrateFocus()
+  if not Context._focusedElementId then
+    Context._focusedElement = nil
+    return
+  end
+
+  -- First, try a fast linear search through all registered elements
+  for _, elem in ipairs(Context._zIndexOrderedElements) do
+    if elem.id == Context._focusedElementId then
+      Context._focusedElement = elem
+      return
+    end
+  end
+
+  -- If not found, recursively search from top-level elements
+  -- This handles cases where elements may not be in _zIndexOrderedElements
+  for _, topLevel in ipairs(Context.topElements or {}) do
+    local found = findElementById(topLevel, Context._focusedElementId)
+    if found then
+      Context._focusedElement = found
+      return
+    end
+  end
+
+  -- Element with that id is not present this frame (e.g. screen changed)
+  Context._focusedElement = nil
+end
+
+--- Get the currently focused element
+---@return Element|nil The focused element, or nil if none
+function Context.getFocused()
+  if Context.isImmediateMode() then
+    Context._rehydrateFocus()
+  end
+  return Context._focusedElement
+end
+
+--- Clear focus from any element
+function Context.clearFocus()
+  Context._focusedElementId = nil
+  Context.setFocused(nil)
+end
+
+--- Get all focusable elements in tab order, regardless of mode.
+--- In immediate mode this extracts from _zIndexOrderedElements (flat, z-sorted).
+--- In retained mode it walks the element tree (DOM order).
+--- In both modes, display:none elements are excluded.
+---@return table<Element> List of focusable elements in tab order
+function Context.getFocusableElements()
+  local focusable = {}
+
+  local function isFocusable(elem)
+    if elem.display == false then
+      return false
+    end
+    -- Use Element:isFocusable() for consistent behavior
+    return Element.isFocusable(elem)
+  end
+
+  local function collectFromTree(elements)
+    for _, elem in ipairs(elements) do
+      if isFocusable(elem) then
+        table.insert(focusable, elem)
+      end
+      if #elem.children > 0 then
+        collectFromTree(elem.children)
+      end
+    end
+  end
+
+  if Context._immediateMode then
+    -- Immediate mode: _zIndexOrderedElements is already in z-index order (lowest first),
+    -- which approximates tab order for most UIs.
+    for _, elem in ipairs(Context._zIndexOrderedElements) do
+      if isFocusable(elem) then
+        table.insert(focusable, elem)
+      end
+    end
+  else
+    -- Retained mode: walk the top element trees in DOM order
+    collectFromTree(Context.topElements)
+  end
+
+  return focusable
+end
+
+-- ====================
+-- Navigation Context
+-- ====================
+
+--- Push current focus onto stack (for modals/dialogs)
+---@param element Element?
+function Context.pushFocusStack(element)
+  Context._navigationContext.lastFocusedElement = Context._focusedElement
+  if element then
+    Context.setFocused(element)
+  end
+end
+
+--- Pop focus from stack (return from modal)
+---@return Element?
+function Context.popFocusStack()
+  local previous = Context._navigationContext.lastFocusedElement
+  Context._navigationContext.lastFocusedElement = nil
+  Context.setFocused(previous)
+  return previous
+end
+
+--- Set navigation container (scope for tab navigation)
+---@param element Element?
+function Context.setNavigationContainer(element)
+  Context._navigationContext.containerElement = element
+end
+
+--- Get navigation container
+---@return Element?
+function Context.getNavigationContainer()
+  return Context._navigationContext.containerElement
+end
+
+return Context

libs/flexlove/modules/Enums.lua

@@ -0,0 +1,171 @@
+-- Layout, flex, text, image, and ARIA enums used across FlexLove.
+-- Extracted from utils so utils stays under its LOC budget; re-exported as
+-- `utils.enums` for backward compatibility.
+
+local enums = {
+  ---@enum TextAlign
+  TextAlign = { START = "start", CENTER = "center", END = "end", JUSTIFY = "justify" },
+  ---@enum TextAlignVertical
+  TextAlignVertical = { START = "start", CENTER = "center", END = "end" },
+  ---@enum Positioning
+  Positioning = { ABSOLUTE = "absolute", RELATIVE = "relative", FLEX = "flex", GRID = "grid" },
+  ---@enum FlexDirection
+  FlexDirection = {
+    HORIZONTAL = "horizontal",
+    VERTICAL = "vertical",
+    ROW = "row",
+    COLUMN = "column",
+    HORIZONTAL_REVERSE = "horizontal-reverse",
+    VERTICAL_REVERSE = "vertical-reverse",
+    ROW_REVERSE = "row-reverse",
+    COLUMN_REVERSE = "column-reverse",
+  },
+  ---@enum JustifyContent
+  JustifyContent = {
+    FLEX_START = "flex-start",
+    CENTER = "center",
+    SPACE_AROUND = "space-around",
+    FLEX_END = "flex-end",
+    SPACE_EVENLY = "space-evenly",
+    SPACE_BETWEEN = "space-between",
+  },
+  ---@enum JustifySelf
+  JustifySelf = {
+    AUTO = "auto",
+    FLEX_START = "flex-start",
+    CENTER = "center",
+    FLEX_END = "flex-end",
+    SPACE_AROUND = "space-around",
+    SPACE_EVENLY = "space-evenly",
+    SPACE_BETWEEN = "space-between",
+  },
+  ---@enum AlignItems
+  AlignItems = {
+    STRETCH = "stretch",
+    FLEX_START = "flex-start",
+    FLEX_END = "flex-end",
+    CENTER = "center",
+    BASELINE = "baseline",
+  },
+  ---@enum AlignSelf
+  AlignSelf = {
+    AUTO = "auto",
+    STRETCH = "stretch",
+    FLEX_START = "flex-start",
+    FLEX_END = "flex-end",
+    CENTER = "center",
+    BASELINE = "baseline",
+  },
+  ---@enum AlignContent
+  AlignContent = {
+    STRETCH = "stretch",
+    FLEX_START = "flex-start",
+    FLEX_END = "flex-end",
+    CENTER = "center",
+    SPACE_BETWEEN = "space-between",
+    SPACE_AROUND = "space-around",
+  },
+  ---@enum FlexWrap
+  FlexWrap = { NOWRAP = "nowrap", WRAP = "wrap", WRAP_REVERSE = "wrap-reverse" },
+  ---@enum TextSize
+  TextSize = {
+    XXS = "xxs",
+    XS = "xs",
+    SM = "sm",
+    MD = "md",
+    LG = "lg",
+    XL = "xl",
+    XXL = "xxl",
+    XL3 = "3xl",
+    XL4 = "4xl",
+  },
+  ---@enum ImageRepeat
+  ImageRepeat = {
+    NO_REPEAT = "no-repeat",
+    REPEAT = "repeat",
+    REPEAT_X = "repeat-x",
+    REPEAT_Y = "repeat-y",
+    SPACE = "space",
+    ROUND = "round",
+  },
+
+  ---@enum ARIA Role (accessibility roles for screen readers)
+  ARIA = {
+    -- Widget roles
+    BUTTON = "button",
+    CHECKBOX = "checkbox",
+    LINK = "link",
+    MENUITEM = "menuitem",
+    MENUITEMCHECKBOX = "menuitemcheckbox",
+    MENUITEMRADIO = "menuitemradio",
+    PROGRESSBAR = "progressbar",
+    RADIO = "radio",
+    SCROLLBAR = "scrollbar",
+    SLIDER = "slider",
+    SPINBUTTON = "spinbutton",
+    SWITCH = "switch",
+    TAB = "tab",
+    TABLIST = "tablist",
+    TABPANEL = "tabpanel",
+    TEXTBOX = "textbox",
+    TOOLTIP = "tooltip",
+    TREEITEM = "treeitem",
+    COMBOBOX = "combobox",
+    GRID = "grid",
+    GRIDCELL = "gridcell",
+    LISTBOX = "listbox",
+    LISTITEM = "listitem",
+    MENU = "menu",
+    MENUBAR = "menubar",
+    TREE = "tree",
+    TREEGRID = "treegrid",
+    WINDOW = "window",
+    DIALOG = "dialog",
+    ALERTDIALOG = "alertdialog",
+
+    -- Landmark roles
+    BANNER = "banner",
+    COMPLEMENTARY = "complementary",
+    CONTENTINFO = "contentinfo",
+    FORM = "form",
+    MAIN = "main",
+    NAVIGATION = "navigation",
+    REGION = "region",
+    SEARCH = "search",
+
+    -- Live region roles
+    ALERT = "alert",
+    LOG = "log",
+    MARQUEE = "marquee",
+    STATUS = "status",
+    TIMERTIME = "timer",
+
+    -- Document structure roles
+    ARTICLE = "article",
+    BLOCKQUOTEBLOCKQUOTE = "blockquote",
+    CAPTION = "caption",
+    CODE = "code",
+    DEFINITION = "definition",
+    DELETED = "deletion",
+    DIRECTORY = "directory",
+    DIVISION = "division",
+    EMphasis = "emphasis",
+    HEADING = "heading",
+    INSERTED = "insertion",
+    LIST = "list",
+    MARK = "mark",
+    MATH = "math",
+    NONE = "none",
+    PARAGRAPH = "paragraph",
+    PRESENTATION = "presentation",
+    SEPARATOR = "separator",
+    STRONG = "strong",
+    SUBSCRIPT = "subscript",
+    SUPERSCRIPT = "superscript",
+    TERM = "term",
+    TIME = "time",
+    VARIABLE = "variable",
+  },
+}
+
+return { enums = enums }

libs/flexlove/modules/EventHandler.lua

@@ -0,0 +1,843 @@
+---@class EventHandler
+---@field onEvent fun(element:Element, event:InputEvent)?
+---@field onEventDeferred boolean?
+---@field onTouchEvent fun(element:Element, touchEvent:InputEvent)? -- Touch-specific callback
+---@field onTouchEventDeferred boolean? -- Whether onTouchEvent is deferred
+---@field onGesture fun(element:Element, gesture:table)? -- Gesture callback
+---@field onGestureDeferred boolean? -- Whether onGesture is deferred
+---@field touchEnabled boolean -- Whether touch events are processed (default: true)
+---@field multiTouchEnabled boolean -- Whether multi-touch is supported (default: false)
+---@field _pressed table<number, boolean>
+---@field _lastClickTime number?
+---@field _lastClickButton number?
+---@field _clickCount number
+---@field _dragStartX table<number, number>
+---@field _dragStartY table<number, number>
+---@field _lastMouseX table<number, number>
+---@field _lastMouseY table<number, number>
+---@field _touches table<string, table> -- Multi-touch state per touch ID
+---@field _touchStartPositions table<string, table> -- Touch start positions
+---@field _lastTouchPositions table<string, table> -- Last touch positions for delta
+---@field _touchHistory table<string, table> -- Touch position history for gestures (last 5)
+---@field _hovered boolean
+---@field _scrollbarPressHandled boolean
+---@field _InputEvent table
+---@field _utils table
+---@field _Performance Performance? Performance module dependency
+---@field _ErrorHandler ErrorHandler
+local EventHandler = {}
+EventHandler.__index = EventHandler
+
+--- Initialize module with shared dependencies
+---@param deps table Dependencies {Performance, ErrorHandler, InputEvent, Context, utils}
+function EventHandler.init(deps)
+  EventHandler._Performance = deps.Performance
+  EventHandler._ErrorHandler = deps.ErrorHandler
+  EventHandler._InputEvent = deps.InputEvent
+  EventHandler._utils = deps.utils
+  EventHandler._Context = deps.Context
+end
+
+---@param config table Configuration options
+---@return EventHandler
+function EventHandler.new(config)
+  config = config or {}
+  local self = setmetatable({}, EventHandler)
+
+  self.onEvent = config.onEvent
+  self.onEventDeferred = config.onEventDeferred
+  self.onTouchEvent = config.onTouchEvent
+  self.onTouchEventDeferred = config.onTouchEventDeferred or false
+  self.onGesture = config.onGesture
+  self.onGestureDeferred = config.onGestureDeferred or false
+  self.touchEnabled = config.touchEnabled ~= false -- Default true
+  self.multiTouchEnabled = config.multiTouchEnabled or false -- Default false
+
+  self._pressed = config._pressed or {}
+
+  self._lastClickTime = config._lastClickTime
+  self._lastClickButton = config._lastClickButton
+  self._clickCount = config._clickCount or 0
+
+  -- FocusIndicator reference (set after initialization)
+  self._FocusIndicator = nil
+
+  self._dragStartX = config._dragStartX or {}
+  self._dragStartY = config._dragStartY or {}
+  self._lastMouseX = config._lastMouseX or {}
+  self._lastMouseY = config._lastMouseY or {}
+
+  -- Multi-touch tracking
+  self._touches = config._touches or {}
+  self._touchStartPositions = config._touchStartPositions or {}
+  self._lastTouchPositions = config._lastTouchPositions or {}
+  self._touchHistory = config._touchHistory or {}
+
+  self._hovered = config._hovered or false
+
+  self._scrollbarPressHandled = false
+
+  return self
+end
+
+--- Get state for persistence (for immediate mode)
+---@return table State data
+function EventHandler:getState()
+  return {
+    _pressed = self._pressed,
+    _lastClickTime = self._lastClickTime,
+    _lastClickButton = self._lastClickButton,
+    _clickCount = self._clickCount,
+    _dragStartX = self._dragStartX,
+    _dragStartY = self._dragStartY,
+    _lastMouseX = self._lastMouseX,
+    _lastMouseY = self._lastMouseY,
+    _touches = self._touches,
+    _touchStartPositions = self._touchStartPositions,
+    _lastTouchPositions = self._lastTouchPositions,
+    _touchHistory = self._touchHistory,
+    _hovered = self._hovered,
+  }
+end
+
+--- Restore state from persistence (for immediate mode)
+---@param state table State data
+function EventHandler:setState(state)
+  if not state then
+    return
+  end
+
+  self._pressed = state._pressed or {}
+  self._lastClickTime = state._lastClickTime
+  self._lastClickButton = state._lastClickButton
+  self._clickCount = state._clickCount or 0
+  self._dragStartX = state._dragStartX or {}
+  self._dragStartY = state._dragStartY or {}
+  self._lastMouseX = state._lastMouseX or {}
+  self._lastMouseY = state._lastMouseY or {}
+  self._touches = state._touches or {}
+  self._touchStartPositions = state._touchStartPositions or {}
+  self._lastTouchPositions = state._lastTouchPositions or {}
+  self._touchHistory = state._touchHistory or {}
+  self._hovered = state._hovered or false
+end
+
+--- Process mouse button events in the update cycle
+---@param element Element The parent element
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param isHovering boolean Whether mouse is over element
+---@param isActiveElement boolean Whether this is the top element at mouse position
+function EventHandler:processMouseEvents(element, mx, my, isHovering, isActiveElement)
+  -- Start performance timing
+  -- Performance accessed via EventHandler._Performance
+  if EventHandler._Performance and EventHandler._Performance.enabled then
+    EventHandler._Performance:startTimer("event_mouse")
+  end
+
+  -- Check if currently dragging (allows drag continuation even if occluded)
+  local isDragging = false
+  for _, button in ipairs({ 1, 2, 3 }) do
+    if self._pressed[button] and love.mouse.isDown(button) then
+      isDragging = true
+      break
+    end
+  end
+
+  -- Check if any button is currently pressed (tracked state)
+  local hasTrackedPress = false
+  for _, button in ipairs({ 1, 2, 3 }) do
+    if self._pressed[button] then
+      hasTrackedPress = true
+      break
+    end
+  end
+
+  -- Can only process events if we have handler, element is enabled, and is active or dragging or has tracked press
+  -- Read onEvent from element (source of truth), fallback to handler cache for backwards compat
+  local canProcessEvents = (
+    element.onEvent
+    or self.onEvent
+    or element.editable
+    or element._selectState
+    or element.selectOption
+  )
+    and element.visibility ~= "hidden"
+    and not element.disabled
+    and (isActiveElement or isDragging or hasTrackedPress)
+
+  if not canProcessEvents then
+    -- If not hovering and no buttons are physically pressed, reset all pressed states
+    -- This ensures the pressed state is cleared when mouse leaves without button held
+    if not isHovering and not isDragging then
+      for _, button in ipairs({ 1, 2, 3 }) do
+        if self._pressed[button] and not love.mouse.isDown(button) then
+          self._pressed[button] = false
+          self._dragStartX[button] = nil
+          self._dragStartY[button] = nil
+        end
+      end
+    end
+
+    -- Track hover state changes even when events can't be processed
+    -- Fire synthetic unhover when element becomes disabled while hovered
+    if element.disabled and self._hovered then
+      self._hovered = false
+      if element.onEvent or self.onEvent then
+        local modifiers = EventHandler._utils.getModifiers()
+        local unhoverEvent = EventHandler._InputEvent.new({
+          type = "unhover",
+          button = 0,
+          x = mx,
+          y = my,
+          modifiers = modifiers,
+          clickCount = 0,
+        })
+        self:_invokeCallback(element, unhoverEvent)
+      end
+    elseif self._hovered and not isHovering then
+      self._hovered = false
+      if element.onEvent or self.onEvent then
+        local modifiers = EventHandler._utils.getModifiers()
+        local unhoverEvent = EventHandler._InputEvent.new({
+          type = "unhover",
+          button = 0,
+          x = mx,
+          y = my,
+          modifiers = modifiers,
+          clickCount = 0,
+        })
+        self:_invokeCallback(element, unhoverEvent)
+      end
+    end
+
+    if EventHandler._Performance and EventHandler._Performance.enabled then
+      EventHandler._Performance:stopTimer("event_mouse")
+    end
+    return
+  end
+
+  -- Track hover state changes and fire hover/unhover events BEFORE button processing
+  -- This ensures hover fires before press when mouse first enters element
+  local wasHovered = self._hovered
+  local isHoveringAndActive = isHovering and isActiveElement
+
+  if isHoveringAndActive and not wasHovered then
+    -- Just started hovering - fire hover event
+    self._hovered = true
+    local modifiers = EventHandler._utils.getModifiers()
+    local hoverEvent = EventHandler._InputEvent.new({
+      type = "hover",
+      button = 0,
+      x = mx,
+      y = my,
+      modifiers = modifiers,
+      clickCount = 0,
+    })
+    self:_invokeCallback(element, hoverEvent)
+  elseif not isHoveringAndActive and wasHovered then
+    -- Just stopped hovering - fire unhover event
+    self._hovered = false
+    local modifiers = EventHandler._utils.getModifiers()
+    local unhoverEvent = EventHandler._InputEvent.new({
+      type = "unhover",
+      button = 0,
+      x = mx,
+      y = my,
+      modifiers = modifiers,
+      clickCount = 0,
+    })
+    self:_invokeCallback(element, unhoverEvent)
+  end
+
+  -- Process all three mouse buttons
+  local buttons = { 1, 2, 3 } -- left, right, middle
+
+  for _, button in ipairs(buttons) do
+    -- Check if this button was tracked as pressed
+    local wasPressed = self._pressed[button]
+    local isPhysicallyPressed = love.mouse.isDown(button)
+
+    if isHovering or isDragging or wasPressed then
+      if isPhysicallyPressed then
+        -- Button is pressed down
+        if not wasPressed then
+          -- Just pressed - fire press event (only if hovering)
+          if isHovering then
+            self:_handleMousePress(element, mx, my, button)
+          end
+        else
+          -- Button is still pressed - check for drag
+          self:_handleMouseDrag(element, mx, my, button, isHovering)
+        end
+      elseif wasPressed then
+        -- Button was just released
+        -- Only fire click and release events if mouse is still hovering AND element is active
+        -- (not occluded by another element)
+        if isHovering and isActiveElement then
+          self:_handleMouseRelease(element, mx, my, button)
+        else
+          -- Mouse left before release OR element is occluded - just clear the pressed state without firing events
+          self._pressed[button] = false
+          self._dragStartX[button] = nil
+          self._dragStartY[button] = nil
+        end
+      end
+    end
+  end
+
+  -- After processing events, reset pressed states for buttons that are no longer held
+  -- This handles the case where mouse leaves while button is held, then released
+  if not isHovering and not isDragging then
+    for _, button in ipairs({ 1, 2, 3 }) do
+      if self._pressed[button] and not love.mouse.isDown(button) then
+        self._pressed[button] = false
+        self._dragStartX[button] = nil
+        self._dragStartY[button] = nil
+      end
+    end
+  end
+
+  -- Stop performance timing
+  if EventHandler._Performance and EventHandler._Performance.enabled then
+    EventHandler._Performance:stopTimer("event_mouse")
+  end
+end
+
+--- Handle mouse button press
+---@param element Element The parent element
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param button number Mouse button (1=left, 2=right, 3=middle)
+function EventHandler:_handleMousePress(element, mx, my, button)
+  -- Check if press is on scrollbar first (skip if already handled)
+  if button == 1 and not self._scrollbarPressHandled and element._handleScrollbarPress then
+    if element:_handleScrollbarPress(mx, my, button) then
+      -- Scrollbar consumed the event, mark as pressed to prevent onEvent
+      self._pressed[button] = true
+      self._scrollbarPressHandled = true
+      return
+    end
+  end
+
+  -- Fire press event
+  local modifiers = EventHandler._utils.getModifiers()
+  local pressEvent = EventHandler._InputEvent.new({
+    type = "press",
+    button = button,
+    x = mx,
+    y = my,
+    modifiers = modifiers,
+    clickCount = 1,
+  })
+  self:_invokeCallback(element, pressEvent)
+
+  self._pressed[button] = true
+
+  -- On left click, set keyboard focus to any focusable element (not just editable).
+  -- Clear the focus indicator since mouse navigation doesn't use it.
+  local isFocusable
+  if type(element.isFocusable) == "function" then
+    isFocusable = element:isFocusable()
+  else
+    isFocusable = (element.editable == true)
+      or (type(element.onEvent) == "function")
+      or element._selectState ~= nil
+      or element.selectOption ~= nil
+  end
+
+  if button == 1 and EventHandler._Context and isFocusable then
+    EventHandler._Context.setFocused(element)
+    -- Hide focus indicator - it's only for keyboard navigation
+    if EventHandler._FocusIndicator then
+      EventHandler._FocusIndicator.setFocused(nil)
+    end
+  end
+  -- Set mouse down position for text selection on left click
+  if button == 1 and element._textEditor then
+    element._mouseDownPosition = element._textEditor:mouseToTextPosition(element, mx, my)
+    element._textDragOccurred = false -- Reset drag flag on press
+  end
+
+  -- Record drag start position per button
+  self._dragStartX[button] = mx
+  self._dragStartY[button] = my
+  self._lastMouseX[button] = mx
+  self._lastMouseY[button] = my
+end
+
+--- Handle mouse drag (while button is pressed and mouse moves)
+---@param element Element The parent element
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param button number Mouse button
+---@param isHovering boolean Whether mouse is over element
+function EventHandler:_handleMouseDrag(element, mx, my, button, isHovering)
+  local lastX = self._lastMouseX[button] or mx
+  local lastY = self._lastMouseY[button] or my
+
+  if lastX ~= mx or lastY ~= my then
+    -- Handle scrollbar drag if scrollbar was pressed
+    if button == 1 and self._scrollbarPressHandled and element._handleScrollbarDrag then
+      element:_handleScrollbarDrag(mx, my)
+      self._lastMouseX[button] = mx
+      self._lastMouseY[button] = my
+      return -- Don't process other drag events while dragging scrollbar
+    end
+
+    -- Mouse has moved - fire drag event only if still hovering
+    if isHovering then
+      local modifiers = EventHandler._utils.getModifiers()
+      local dx = mx - self._dragStartX[button]
+      local dy = my - self._dragStartY[button]
+
+      local dragEvent = EventHandler._InputEvent.new({
+        type = "drag",
+        button = button,
+        x = mx,
+        y = my,
+        dx = dx,
+        dy = dy,
+        modifiers = modifiers,
+        clickCount = 1,
+      })
+      self:_invokeCallback(element, dragEvent)
+    end
+
+    -- Handle text selection drag for editable elements
+    if button == 1 and element.editable and element._focused and element._handleTextDrag then
+      element:_handleTextDrag(mx, my)
+    end
+
+    -- Update last known position for this button
+    self._lastMouseX[button] = mx
+    self._lastMouseY[button] = my
+  end
+end
+
+--- Handle mouse button release
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param button number Mouse button
+function EventHandler:_handleMouseRelease(element, mx, my, button)
+  local currentTime = love.timer.getTime()
+  local modifiers = EventHandler._utils.getModifiers()
+
+  -- Handle scrollbar release if scrollbar was pressed
+  if button == 1 and self._scrollbarPressHandled and element._handleScrollbarRelease then
+    element:_handleScrollbarRelease(button)
+    self._scrollbarPressHandled = false -- Reset flag
+    self._pressed[button] = false
+    self._dragStartX[button] = nil
+    self._dragStartY[button] = nil
+    return -- Don't process click events for scrollbar release
+  end
+
+  -- Determine click count (double-click detection)
+  local clickCount
+  local doubleClickThreshold = 0.3 -- 300ms for double-click
+
+  if
+    self._lastClickTime
+    and self._lastClickButton == button
+    and (currentTime - self._lastClickTime) < doubleClickThreshold
+  then
+    clickCount = self._clickCount + 1
+  else
+    clickCount = 1
+  end
+
+  self._clickCount = clickCount
+  self._lastClickTime = currentTime
+  self._lastClickButton = button
+
+  -- Determine event type based on button
+  local eventType = "click"
+  if button == 2 then
+    eventType = "rightclick"
+  elseif button == 3 then
+    eventType = "middleclick"
+  end
+
+  -- Fire click event
+  local clickEvent = EventHandler._InputEvent.new({
+    type = eventType,
+    button = button,
+    x = mx,
+    y = my,
+    modifiers = modifiers,
+    clickCount = clickCount,
+  })
+  self:_invokeCallback(element, clickEvent)
+
+  self._pressed[button] = false
+
+  -- Clean up drag tracking
+  self._dragStartX[button] = nil
+  self._dragStartY[button] = nil
+
+  -- Clean up text selection drag tracking
+  if button == 1 then
+    element._mouseDownPosition = nil
+  end
+
+  -- Focus editable elements on left click
+  if button == 1 and element.editable then
+    -- Only focus if not already focused (to avoid moving cursor to end)
+    local wasFocused = element:isFocused()
+    if not wasFocused then
+      element:focus()
+    end
+
+    -- Handle text click for cursor positioning and word selection
+    -- Only process click if no text drag occurred (to preserve drag selection)
+    if element._handleTextClick and not element._textDragOccurred then
+      element:_handleTextClick(mx, my, clickCount)
+    end
+
+    -- Reset drag flag after release
+    element._textDragOccurred = false
+  end
+
+  -- Fire release event
+  local releaseEvent = EventHandler._InputEvent.new({
+    type = "release",
+    button = button,
+    x = mx,
+    y = my,
+    modifiers = modifiers,
+    clickCount = clickCount,
+  })
+  self:_invokeCallback(element, releaseEvent)
+
+  if button == 1 and element._handleSelectRelease then
+    element:_handleSelectRelease()
+  end
+end
+
+--- Process touch events in the update cycle
+---@param element Element The parent element
+function EventHandler:processTouchEvents(element)
+  -- Start performance timing
+  if EventHandler._Performance and EventHandler._Performance.enabled then
+    EventHandler._Performance:startTimer("event_touch")
+  end
+
+  -- Check if element can process events
+  local canProcessEvents = (
+    element.onEvent
+    or self.onEvent
+    or element.onTouchEvent
+    or self.onTouchEvent
+    or element.editable
+  )
+    and not element.disabled
+    and self.touchEnabled
+
+  if not canProcessEvents then
+    if EventHandler._Performance and EventHandler._Performance.enabled then
+      EventHandler._Performance:stopTimer("event_touch")
+    end
+    return
+  end
+
+  local bx = element.x
+  local by = element.y
+  local bw = element._borderBoxWidth or (element.width + element.padding.left + element.padding.right)
+  local bh = element._borderBoxHeight or (element.height + element.padding.top + element.padding.bottom)
+
+  -- Get current active touches from LÖVE
+  local activeTouches = {}
+  local touches = love.touch.getTouches()
+  for _, id in ipairs(touches) do
+    activeTouches[tostring(id)] = true
+  end
+
+  -- Count active tracked touches for multi-touch filtering
+  local trackedTouchCount = 0
+  for _ in pairs(self._touches) do
+    trackedTouchCount = trackedTouchCount + 1
+  end
+
+  -- Process active touches
+  for _, id in ipairs(touches) do
+    local touchId = tostring(id)
+    local tx, ty = love.touch.getPosition(id)
+    local pressure = 1.0 -- LÖVE doesn't provide pressure by default
+
+    -- Check if touch is within element bounds
+    local isInside = tx >= bx and tx <= bx + bw and ty >= by and ty <= by + bh
+
+    if isInside then
+      if not self._touches[touchId] then
+        -- Multi-touch filtering: reject new touches when multiTouchEnabled=false
+        -- and we already have an active touch
+        if self.multiTouchEnabled or trackedTouchCount == 0 then
+          -- New touch began
+          self:_handleTouchBegan(element, touchId, tx, ty, pressure)
+          trackedTouchCount = trackedTouchCount + 1
+        end
+      else
+        -- Touch moved
+        self:_handleTouchMoved(element, touchId, tx, ty, pressure)
+      end
+    elseif self._touches[touchId] then
+      -- Touch moved outside or ended
+      if activeTouches[touchId] then
+        -- Still active but outside - fire moved event
+        self:_handleTouchMoved(element, touchId, tx, ty, pressure)
+      else
+        -- Touch ended
+        self:_handleTouchEnded(element, touchId, tx, ty, pressure)
+      end
+    end
+  end
+
+  -- Check for ended touches (touches that were tracked but are no longer active)
+  for touchId, _ in pairs(self._touches) do
+    if not activeTouches[touchId] then
+      -- Touch ended or cancelled
+      local lastPos = self._lastTouchPositions[touchId]
+      if lastPos then
+        self:_handleTouchEnded(element, touchId, lastPos.x, lastPos.y, 1.0)
+      else
+        -- Cleanup orphaned touch
+        self:_cleanupTouch(touchId)
+      end
+    end
+  end
+
+  -- Stop performance timing
+  if EventHandler._Performance and EventHandler._Performance.enabled then
+    EventHandler._Performance:stopTimer("event_touch")
+  end
+end
+
+--- Handle touch began event
+---@param element Element The parent element
+---@param touchId string Touch identifier
+---@param x number Touch X position
+---@param y number Touch Y position
+---@param pressure number Touch pressure (0-1)
+function EventHandler:_handleTouchBegan(element, touchId, x, y, pressure)
+  -- Create touch state
+  self._touches[touchId] = {
+    x = x,
+    y = y,
+    pressure = pressure,
+    timestamp = love.timer.getTime(),
+    phase = "began",
+  }
+
+  -- Record start position
+  self._touchStartPositions[touchId] = { x = x, y = y }
+  self._lastTouchPositions[touchId] = { x = x, y = y }
+
+  -- Initialize touch history
+  self._touchHistory[touchId] = { { x = x, y = y, timestamp = love.timer.getTime() } }
+
+  -- Create and fire touch press event
+  local touchEvent = EventHandler._InputEvent.fromTouch(touchId, x, y, "began", pressure)
+  touchEvent.type = "touchpress"
+  touchEvent.dx = 0
+  touchEvent.dy = 0
+  self:_invokeCallback(element, touchEvent)
+  self:_invokeTouchCallback(element, touchEvent)
+end
+
+--- Handle touch moved event
+---@param element Element The parent element
+---@param touchId string Touch identifier
+---@param x number Touch X position
+---@param y number Touch Y position
+---@param pressure number Touch pressure (0-1)
+function EventHandler:_handleTouchMoved(element, touchId, x, y, pressure)
+  local touchState = self._touches[touchId]
+
+  if not touchState then
+    -- Touch not tracked, ignore
+    return
+  end
+
+  local lastPos = self._lastTouchPositions[touchId]
+  if not lastPos or lastPos.x ~= x or lastPos.y ~= y then
+    -- Touch position changed
+    local startPos = self._touchStartPositions[touchId]
+    local dx = x - startPos.x
+    local dy = y - startPos.y
+
+    -- Update touch state
+    touchState.x = x
+    touchState.y = y
+    touchState.pressure = pressure
+    touchState.phase = "moved"
+
+    -- Update last position
+    self._lastTouchPositions[touchId] = { x = x, y = y }
+
+    -- Add to touch history (keep last 5 positions)
+    local history = self._touchHistory[touchId] or {}
+    table.insert(history, { x = x, y = y, timestamp = love.timer.getTime() })
+    if #history > 5 then
+      table.remove(history, 1)
+    end
+    self._touchHistory[touchId] = history
+
+    -- Create and fire touch move event
+    local touchEvent = EventHandler._InputEvent.fromTouch(touchId, x, y, "moved", pressure)
+    touchEvent.type = "touchmove"
+    touchEvent.dx = dx
+    touchEvent.dy = dy
+    self:_invokeCallback(element, touchEvent)
+    self:_invokeTouchCallback(element, touchEvent)
+  end
+end
+
+--- Handle touch ended event
+---@param element Element The parent element
+---@param touchId string Touch identifier
+---@param x number Touch X position
+---@param y number Touch Y position
+---@param pressure number Touch pressure (0-1)
+function EventHandler:_handleTouchEnded(element, touchId, x, y, pressure)
+  local touchState = self._touches[touchId]
+
+  if not touchState then
+    -- Touch not tracked, ignore
+    return
+  end
+
+  local startPos = self._touchStartPositions[touchId]
+  local dx = x - startPos.x
+  local dy = y - startPos.y
+
+  -- Create and fire touch release event
+  local touchEvent = EventHandler._InputEvent.fromTouch(touchId, x, y, "ended", pressure)
+  touchEvent.type = "touchrelease"
+  touchEvent.dx = dx
+  touchEvent.dy = dy
+  self:_invokeCallback(element, touchEvent)
+  self:_invokeTouchCallback(element, touchEvent)
+
+  -- Cleanup touch state
+  self:_cleanupTouch(touchId)
+end
+
+--- Cleanup touch state
+---@param touchId string Touch ID
+function EventHandler:_cleanupTouch(touchId)
+  self._touches[touchId] = nil
+  self._touchStartPositions[touchId] = nil
+  self._lastTouchPositions[touchId] = nil
+  self._touchHistory[touchId] = nil
+end
+
+--- Get active touches on this element
+---@return table<string, table> Active touches
+function EventHandler:getActiveTouches()
+  return self._touches
+end
+
+--- Reset scrollbar press flag (called each frame)
+function EventHandler:resetScrollbarPressFlag()
+  self._scrollbarPressHandled = false
+end
+
+--- Check if any mouse button is pressed
+---@return boolean True if any button is pressed
+function EventHandler:isAnyButtonPressed()
+  for _, pressed in pairs(self._pressed) do
+    if pressed then
+      return true
+    end
+  end
+  return false
+end
+
+--- Check if a specific button is pressed
+---@param button number Mouse button (1=left, 2=right, 3=middle)
+---@return boolean True if button is pressed
+function EventHandler:isButtonPressed(button)
+  return self._pressed[button] == true
+end
+
+--- Invoke the onEvent callback, optionally deferring it if onEventDeferred is true
+---@param element Element The element that triggered the event
+---@param event InputEvent The event data
+function EventHandler:_invokeCallback(element, event)
+  -- Read onEvent from element (source of truth), fallback to handler cache for backwards compat
+  local callback = element.onEvent or self.onEvent
+  if not callback then
+    return
+  end
+
+  if self.onEventDeferred then
+    -- Get FlexLove module to defer the callback
+    local FlexLove = package.loaded["FlexLove"] or package.loaded["libs.FlexLove"]
+    if FlexLove and FlexLove.deferCallback then
+      FlexLove.deferCallback(function()
+        callback(element, event)
+      end)
+    else
+      EventHandler._ErrorHandler:error("EventHandler", "SYS_003", {
+        eventType = event.type,
+      })
+    end
+  else
+    callback(element, event)
+  end
+end
+
+--- Invoke the onTouchEvent callback, optionally deferring it
+---@param element Element The element that triggered the event
+---@param event InputEvent The touch event data
+function EventHandler:_invokeTouchCallback(element, event)
+  -- Read onTouchEvent from element (source of truth), fallback to handler cache for backwards compat
+  local callback = element.onTouchEvent or self.onTouchEvent
+  if not callback then
+    return
+  end
+
+  if self.onTouchEventDeferred then
+    local FlexLove = package.loaded["FlexLove"] or package.loaded["libs.FlexLove"]
+    if FlexLove and FlexLove.deferCallback then
+      FlexLove.deferCallback(function()
+        callback(element, event)
+      end)
+    else
+      EventHandler._ErrorHandler:error("EventHandler", "SYS_003", {
+        eventType = event.type,
+      })
+    end
+  else
+    callback(element, event)
+  end
+end
+
+--- Invoke the onGesture callback, optionally deferring it
+---@param element Element The element that triggered the event
+---@param gesture table The gesture data from GestureRecognizer
+function EventHandler:_invokeGestureCallback(element, gesture)
+  -- Read onGesture from element (source of truth), fallback to handler cache for backwards compat
+  local callback = element.onGesture or self.onGesture
+  if not callback then
+    return
+  end
+
+  if self.onGestureDeferred then
+    local FlexLove = package.loaded["FlexLove"] or package.loaded["libs.FlexLove"]
+    if FlexLove and FlexLove.deferCallback then
+      FlexLove.deferCallback(function()
+        callback(element, gesture)
+      end)
+    else
+      EventHandler._ErrorHandler:error("EventHandler", "SYS_003", {
+        gestureType = gesture.type,
+      })
+    end
+  else
+    callback(element, gesture)
+  end
+end
+
+return EventHandler

libs/flexlove/modules/FocusIndicator.lua

@@ -0,0 +1,232 @@
+local packageName = ... or "FocusIndicator"
+local modulePath = packageName:match("(.-)[^%.]+$")
+
+local function req(name)
+  return require(modulePath .. name)
+end
+
+local FocusIndicator = {}
+
+--- Configuration
+---@type KeyboardNavigationFocusIndicatorConfig
+FocusIndicator.config = {
+  enabled = true,
+
+  --- Custom draw function to override default rendering
+  ---@type function|nil
+  --- Called with: element, bounds, style - return true to skip default drawing
+  draw = nil,
+
+  -- Appearance
+  color = { 0.2, 0.6, 1.0, 0.8 }, -- Blue with 80% opacity
+  lineWidth = 2,
+  inset = -3, -- Negative value extends beyond element
+  borderRadius = 4,
+
+  -- Animation
+  animationDuration = 0.15, -- Seconds for focus animation
+  pulseEnabled = false, -- Enable pulsing animation
+  pulseDuration = 1.0, -- Seconds per pulse cycle
+  pulseScaleMin = 0.95, -- Minimum scale during pulse
+  pulseScaleMax = 1.05, -- Maximum scale during pulse
+}
+
+--- State
+FocusIndicator._focusedElement = nil
+FocusIndicator._animationProgress = 0
+FocusIndicator._pulsePhase = 0
+FocusIndicator._hidden = true
+FocusIndicator._deps = nil
+
+--- Initialize FocusIndicator module
+---@param deps table Dependencies table containing Context and Color modules
+---@field deps.Context table Context module for getting focused element
+---@field deps.Color table Color module for color manipulation
+function FocusIndicator.init(deps)
+  FocusIndicator._deps = deps
+  FocusIndicator._Context = deps.Context
+  FocusIndicator._Color = deps.Color
+end
+
+--- Update animation state for entrance and pulse effects
+---@param dt number Delta time in seconds since last frame
+function FocusIndicator:update(dt)
+  if not FocusIndicator.config.enabled then
+    return
+  end
+
+  -- Update focus entrance animation
+  if FocusIndicator._animationProgress < 1 then
+    FocusIndicator._animationProgress =
+      math.min(1, FocusIndicator._animationProgress + (dt / FocusIndicator.config.animationDuration))
+  end
+
+  -- Update pulse animation
+  if FocusIndicator.config.pulseEnabled then
+    FocusIndicator._pulsePhase = (FocusIndicator._pulsePhase + dt) % FocusIndicator.config.pulseDuration
+  end
+end
+
+--- Set the focused element to render indicator around
+---@param element Element? The element to show focus indicator around, or nil to hide
+function FocusIndicator.setFocused(element)
+  FocusIndicator._focusedElement = element
+  FocusIndicator._hidden = element == nil
+  -- Reset animation when focus changes
+  if element then
+    FocusIndicator._animationProgress = 0
+  end
+end
+
+--- Get the current scale factor for animations
+--- Combines entrance scale (0.8 to 1.0) with optional pulse scale
+---@return number Scale factor (typically 0.8-1.05 range)
+function FocusIndicator:getScale()
+  local scale = 1
+
+  -- Apply entrance animation (scale up from 0.8)
+  local entranceScale = 0.8 + (0.2 * FocusIndicator._animationProgress)
+  scale = scale * entranceScale
+
+  -- Apply pulse animation
+  if FocusIndicator.config.pulseEnabled then
+    local pulseProgress = FocusIndicator._pulsePhase / FocusIndicator.config.pulseDuration
+    -- Smooth sine wave pulse
+    local pulseScale = FocusIndicator.config.pulseScaleMin
+      + (FocusIndicator.config.pulseScaleMax - FocusIndicator.config.pulseScaleMin)
+        * (0.5 + 0.5 * math.sin(2 * math.pi * pulseProgress))
+    scale = scale * pulseScale
+  end
+
+  return scale
+end
+
+--- Get the current opacity for the indicator
+--- Applies entrance animation fade-in to the configured alpha
+---@return number Alpha value (0-1 range)
+function FocusIndicator:getOpacity()
+  -- Fade in on focus
+  return FocusIndicator.config.color[4] * FocusIndicator._animationProgress
+end
+
+--- Draw the focus indicator around the focused element
+--- Renders a rounded rectangle border, or calls custom draw function if configured
+--- Should be called from within love.draw() after all elements are drawn
+function FocusIndicator:draw()
+  if not FocusIndicator.config.enabled then
+    return
+  end
+
+  if FocusIndicator._hidden then
+    return
+  end
+
+  -- In immediate mode the stored element reference is stale (recreated every frame).
+  -- Always resolve through Context so we get the live object with up-to-date positions.
+  local element
+  if FocusIndicator._Context then
+    element = FocusIndicator._Context.getFocused()
+  else
+    element = FocusIndicator._focusedElement
+  end
+
+  if not element then
+    return
+  end
+
+  -- Get element dimensions (use border-box size which includes padding)
+  local x = element.x or 0
+  local y = element.y or 0
+  local w = element._borderBoxWidth
+    or (element.width + (element.padding and (element.padding.left + element.padding.right) or 0))
+  local h = element._borderBoxHeight
+    or (element.height + (element.padding and (element.padding.top + element.padding.bottom) or 0))
+
+  if w == 0 or h == 0 then
+    return
+  end
+
+  -- Calculate indicator dimensions with inset and scale
+  local inset = FocusIndicator.config.inset
+  local scale = self:getScale()
+
+  local indicatorX = x + inset
+  local indicatorY = y + inset
+  local indicatorW = w - 2 * inset
+  local indicatorH = h - 2 * inset
+
+  -- Center the scale around the element
+  local offsetX = (indicatorW * (1 - scale)) / 2
+  local offsetY = (indicatorH * (1 - scale)) / 2
+
+  indicatorX = indicatorX + offsetX
+  indicatorY = indicatorY + offsetY
+  indicatorW = indicatorW * scale
+  indicatorH = indicatorH * scale
+
+  -- Get color with animated opacity
+  local r, g, b = FocusIndicator.config.color[1], FocusIndicator.config.color[2], FocusIndicator.config.color[3]
+  local a = self:getOpacity()
+
+  -- Build style table for custom draw callback
+  local bounds = {
+    x = indicatorX,
+    y = indicatorY,
+    width = indicatorW,
+    height = indicatorH,
+  }
+
+  local style = {
+    color = { r = r, g = g, b = b, a = a },
+    lineWidth = FocusIndicator.config.lineWidth,
+    borderRadius = FocusIndicator.config.borderRadius,
+    scale = scale,
+    opacity = a,
+  }
+
+  -- Check for custom draw callback
+  if FocusIndicator.config.draw then
+    local skipDefault = FocusIndicator.config.draw(element, bounds, style)
+    if skipDefault then
+      return
+    end
+  end
+
+  -- Save current love.graphics state
+  local prevBlend, prevAlphaMode = love.graphics.getBlendMode()
+  local prevR, prevG, prevB, prevA = love.graphics.getColor()
+  local prevLineWidth = love.graphics.getLineWidth()
+
+  -- Set blend mode for transparency
+  love.graphics.setBlendMode("alpha")
+
+  -- Draw rounded rectangle border
+  love.graphics.setColor(r, g, b, a)
+  love.graphics.setLineWidth(FocusIndicator.config.lineWidth)
+
+  -- Draw the rounded rectangle border
+  local borderRadius = FocusIndicator.config.borderRadius
+  love.graphics.rectangle("line", indicatorX, indicatorY, indicatorW, indicatorH, borderRadius)
+
+  -- Restore love.graphics state
+  love.graphics.setBlendMode(prevBlend, prevAlphaMode)
+  love.graphics.setColor(prevR, prevG, prevB, prevA)
+  love.graphics.setLineWidth(prevLineWidth)
+end
+
+--- Set the indicator color
+---@param r number Red component (0-1 range)
+---@param g number Green component (0-1 range)
+---@param b number Blue component (0-1 range)
+---@param a number|nil Alpha component (0-1 range), defaults to current alpha if omitted
+function FocusIndicator.setColor(r, g, b, a)
+  FocusIndicator.config.color = { r, g, b, a or FocusIndicator.config.color[4] }
+end
+
+--- Set the stroke width for the indicator border
+---@param width number Line width in pixels
+function FocusIndicator.setLineWidth(width)
+  FocusIndicator.config.lineWidth = width
+end
+
+return FocusIndicator

libs/flexlove/modules/FontCache.lua

@@ -0,0 +1,269 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+-- Font cache with LRU eviction, font resolution, and cache management.
+-- `ErrorHandler` and `resolveImagePath` are injected via init() to avoid
+-- a cross-import into utils (utils re-exports the cache via aliases).
+
+-- Font cache with LRU eviction
+local FONT_CACHE = {}
+local FONT_CACHE_MAX_SIZE = 50
+local FONT_CACHE_STATS = {
+  hits = 0,
+  misses = 0,
+  evictions = 0,
+  size = 0,
+}
+
+local ErrorHandler = nil
+local resolveImagePath = nil
+
+--- Initialize dependencies
+---@param deps table Dependencies: { ErrorHandler = ErrorHandler, resolveImagePath = function }
+local function init(deps)
+  if type(deps) == "table" then
+    ErrorHandler = deps.ErrorHandler
+    resolveImagePath = deps.resolveImagePath
+  end
+end
+
+-- LRU tracking: each entry has {font, lastUsed, accessCount}
+local function updateCacheAccess(cacheKey)
+  local entry = FONT_CACHE[cacheKey]
+  if entry then
+    entry.lastUsed = love.timer.getTime()
+    entry.accessCount = entry.accessCount + 1
+  end
+end
+
+local function evictLRU()
+  local oldestKey = nil
+  local oldestTime = math.huge
+
+  for key, entry in pairs(FONT_CACHE) do
+    -- Skip methods (get, getFont) - only evict cache entries (tables with lastUsed)
+    if type(entry) == "table" and entry.lastUsed then
+      if entry.lastUsed < oldestTime then
+        oldestTime = entry.lastUsed
+        oldestKey = key
+      end
+    end
+  end
+
+  if oldestKey then
+    FONT_CACHE[oldestKey] = nil
+    FONT_CACHE_STATS.evictions = FONT_CACHE_STATS.evictions + 1
+    FONT_CACHE_STATS.size = FONT_CACHE_STATS.size - 1
+  end
+end
+
+--- Create or get a font from cache
+---@param size number
+---@param fontPath string?
+---@return love.Font
+function FONT_CACHE.get(size, fontPath)
+  -- Bucket font sizes for better cache reuse (reduces unique cache entries)
+  -- Small sizes (< 20): round to nearest 2
+  -- Medium sizes (20-40): round to nearest 4
+  -- Large sizes (> 40): round to nearest 8
+  if size < 20 then
+    size = math.floor((size + 1) / 2) * 2
+  elseif size < 40 then
+    size = math.floor((size + 2) / 4) * 4
+  else
+    size = math.floor((size + 4) / 8) * 8
+  end
+
+  local cacheKey = fontPath and (fontPath .. ":" .. tostring(size)) or ("default:" .. tostring(size))
+
+  if FONT_CACHE[cacheKey] then
+    -- Cache hit
+    FONT_CACHE_STATS.hits = FONT_CACHE_STATS.hits + 1
+    updateCacheAccess(cacheKey)
+    return FONT_CACHE[cacheKey].font
+  end
+
+  -- Cache miss
+  FONT_CACHE_STATS.misses = FONT_CACHE_STATS.misses + 1
+
+  local font
+  if fontPath then
+    local resolvedPath = resolveImagePath(fontPath)
+    local success, result = pcall(love.graphics.newFont, resolvedPath, size)
+    if success then
+      font = result
+    else
+      if ErrorHandler then
+        ErrorHandler:warn("utils", "RES_004", {
+          resourceType = "font",
+          path = fontPath,
+        })
+      end
+      font = love.graphics.newFont(size)
+    end
+  else
+    font = love.graphics.newFont(size)
+  end
+
+  -- Add to cache with LRU metadata
+  FONT_CACHE[cacheKey] = {
+    font = font,
+    lastUsed = love.timer.getTime(),
+    accessCount = 1,
+  }
+  FONT_CACHE_STATS.size = FONT_CACHE_STATS.size + 1
+
+  -- Evict if cache is full
+  if FONT_CACHE_STATS.size > FONT_CACHE_MAX_SIZE then
+    evictLRU()
+  end
+
+  return font
+end
+
+--- Get font for text size (cached)
+---@param textSize number?
+---@param fontPath string?
+---@return love.Font
+function FONT_CACHE.getFont(textSize, fontPath)
+  if textSize then
+    return FONT_CACHE.get(textSize, fontPath)
+  else
+    return love.graphics.getFont()
+  end
+end
+
+-- Font resolution utilities
+
+--- Resolve font path from fontFamily and theme
+---@param fontFamily string? Font family name or direct path
+---@param themeComponent string? Theme component name
+---@param themeManager table? ThemeManager instance
+---@return string? Resolved font path or nil
+local function resolveFontPath(fontFamily, themeComponent, themeManager)
+  if fontFamily then
+    -- Check if fontFamily is a theme font name
+    local themeToUse = themeManager and themeManager:getTheme()
+    if themeToUse and themeToUse.fonts and themeToUse.fonts[fontFamily] then
+      return themeToUse.fonts[fontFamily]
+    else
+      -- Treat as direct path to font file
+      return fontFamily
+    end
+  elseif themeComponent and themeManager then
+    -- If using themeComponent but no fontFamily specified, check for default font in theme
+    return themeManager:getDefaultFontFamily()
+  end
+  return nil
+end
+
+--- Get font for element (resolves from theme or fontFamily)
+---@param textSize number? Text size in pixels
+---@param fontFamily string? Font family name or direct path
+---@param themeComponent string? Theme component name
+---@param themeManager table? ThemeManager instance
+---@return love.Font
+local function getFont(textSize, fontFamily, themeComponent, themeManager)
+  local fontPath = resolveFontPath(fontFamily, themeComponent, themeManager)
+  return FONT_CACHE.getFont(textSize, fontPath)
+end
+
+-- Font cache management
+
+--- Get font cache statistics
+---@return table stats {hits, misses, evictions, size, hitRate}
+local function getFontCacheStats()
+  local total = FONT_CACHE_STATS.hits + FONT_CACHE_STATS.misses
+  local hitRate = total > 0 and (FONT_CACHE_STATS.hits / total) or 0
+  return {
+    hits = FONT_CACHE_STATS.hits,
+    misses = FONT_CACHE_STATS.misses,
+    evictions = FONT_CACHE_STATS.evictions,
+    size = FONT_CACHE_STATS.size,
+    hitRate = hitRate,
+  }
+end
+
+--- Set maximum font cache size
+---@param maxSize number Maximum number of fonts to cache
+local function setFontCacheSize(maxSize)
+  FONT_CACHE_MAX_SIZE = math.max(1, maxSize)
+
+  -- Evict entries if cache is now over limit
+  while FONT_CACHE_STATS.size > FONT_CACHE_MAX_SIZE do
+    evictLRU()
+  end
+end
+
+--- Clear font cache
+local function clearFontCache()
+  -- Clear cache entries but preserve methods (get, getFont)
+  for key, entry in pairs(FONT_CACHE) do
+    if type(entry) == "table" and entry.lastUsed then
+      FONT_CACHE[key] = nil
+    end
+  end
+  FONT_CACHE_STATS.size = 0
+  FONT_CACHE_STATS.evictions = 0
+end
+
+--- Preload font at multiple sizes
+---@param fontPath string? Path to font file (nil for default font)
+---@param sizes table Array of font sizes to preload
+local function preloadFont(fontPath, sizes)
+  for _, size in ipairs(sizes) do
+    -- Round size to reduce cache entries
+    size = math.floor(size + 0.5)
+
+    local cacheKey = fontPath and (fontPath .. ":" .. tostring(size)) or ("default:" .. tostring(size))
+
+    if not FONT_CACHE[cacheKey] then
+      local font
+      if fontPath then
+        local resolvedPath = resolveImagePath(fontPath)
+        local success, result = pcall(love.graphics.newFont, resolvedPath, size)
+        if success then
+          font = result
+        else
+          font = love.graphics.newFont(size)
+        end
+      else
+        font = love.graphics.newFont(size)
+      end
+
+      FONT_CACHE[cacheKey] = {
+        font = font,
+        lastUsed = love.timer.getTime(),
+        accessCount = 1,
+      }
+      FONT_CACHE_STATS.size = FONT_CACHE_STATS.size + 1
+      FONT_CACHE_STATS.misses = FONT_CACHE_STATS.misses + 1
+
+      -- Evict if cache is full
+      if FONT_CACHE_STATS.size > FONT_CACHE_MAX_SIZE then
+        evictLRU()
+      end
+    end
+  end
+end
+
+--- Reset font cache statistics
+local function resetFontCacheStats()
+  FONT_CACHE_STATS.hits = 0
+  FONT_CACHE_STATS.misses = 0
+  FONT_CACHE_STATS.evictions = 0
+end
+
+return {
+  FONT_CACHE = FONT_CACHE,
+  init = init,
+  resolveFontPath = resolveFontPath,
+  getFont = getFont,
+  getFontCacheStats = getFontCacheStats,
+  setFontCacheSize = setFontCacheSize,
+  clearFontCache = clearFontCache,
+  preloadFont = preloadFont,
+  resetFontCacheStats = resetFontCacheStats,
+}

libs/flexlove/modules/GestureRecognizer.lua

@@ -0,0 +1,583 @@
+---@class GestureRecognizer
+---@field _touches table<string, table> -- Current touch states
+---@field _gestureStates table -- Active gesture states
+---@field _config table -- Gesture configuration (thresholds, etc.)
+---@field _InputEvent table
+---@field _utils table
+local GestureRecognizer = {}
+GestureRecognizer.__index = GestureRecognizer
+
+-- Gesture types enum
+local GestureType = {
+  TAP = "tap",
+  DOUBLE_TAP = "double_tap",
+  LONG_PRESS = "long_press",
+  SWIPE = "swipe",
+  PAN = "pan",
+  PINCH = "pinch",
+  ROTATE = "rotate",
+}
+
+-- Gesture states
+local GestureState = {
+  POSSIBLE = "possible",
+  BEGAN = "began",
+  CHANGED = "changed",
+  ENDED = "ended",
+  CANCELLED = "cancelled",
+  FAILED = "failed",
+}
+
+-- Default configuration
+local defaultConfig = {
+  -- Tap gesture
+  tapMaxDuration = 0.3, -- seconds
+  tapMaxMovement = 10, -- pixels
+
+  -- Double-tap gesture
+  doubleTapInterval = 0.3, -- seconds between taps
+
+  -- Long-press gesture
+  longPressMinDuration = 0.5, -- seconds
+  longPressMaxMovement = 10, -- pixels
+
+  -- Swipe gesture
+  swipeMinDistance = 50, -- pixels
+  swipeMaxDuration = 0.2, -- seconds
+  swipeMinVelocity = 200, -- pixels per second
+
+  -- Pan gesture
+  panMinMovement = 5, -- pixels to start pan
+
+  -- Pinch gesture
+  pinchMinScaleChange = 0.1, -- 10% scale change
+
+  -- Rotate gesture
+  rotateMinAngleChange = 5, -- degrees
+}
+
+--- Create a new GestureRecognizer instance
+---@param config table? Optional configuration options
+---@param deps table Dependencies {InputEvent, utils}
+---@return GestureRecognizer
+function GestureRecognizer.new(config, deps)
+  config = config or {}
+
+  local self = setmetatable({}, GestureRecognizer)
+
+  self._InputEvent = deps.InputEvent
+  self._utils = deps.utils
+
+  -- Merge configuration with defaults
+  self._config = {}
+  for key, value in pairs(defaultConfig) do
+    self._config[key] = config[key] or value
+  end
+
+  self._touches = {}
+  self._gestureStates = {
+    tap = nil,
+    doubleTap = { lastTapTime = 0, tapCount = 0 },
+    longPress = {},
+    swipe = {},
+    pan = {},
+    pinch = {},
+    rotate = {},
+  }
+
+  return self
+end
+
+--- Update gesture recognizer with touch event
+---@param event InputEvent Touch event
+function GestureRecognizer:processTouchEvent(event)
+  if not event.touchId then
+    return nil
+  end
+
+  local touchId = event.touchId
+  local gestures = {}
+
+  -- Update touch state
+  if event.type == "touchpress" then
+    self._touches[touchId] = {
+      startX = event.x,
+      startY = event.y,
+      x = event.x,
+      y = event.y,
+      startTime = event.timestamp,
+      lastTime = event.timestamp,
+      phase = "began",
+    }
+
+    -- Initialize gesture detection
+    self:_detectTapBegan(touchId, event)
+    self:_detectLongPressBegan(touchId, event)
+  elseif event.type == "touchmove" then
+    local touch = self._touches[touchId]
+    if touch then
+      touch.x = event.x
+      touch.y = event.y
+      touch.lastTime = event.timestamp
+      touch.phase = "moved"
+
+      -- Update gesture detection
+      local panGesture = self:_detectPan(touchId, event)
+      if panGesture then
+        table.insert(gestures, panGesture)
+      end
+      local swipeGesture = self:_detectSwipe(touchId, event)
+      if swipeGesture then
+        table.insert(gestures, swipeGesture)
+      end
+
+      -- Multi-touch gestures
+      if self:_getTouchCount() >= 2 then
+        local pinchGesture = self:_detectPinch(event)
+        if pinchGesture then
+          table.insert(gestures, pinchGesture)
+        end
+        local rotateGesture = self:_detectRotate(event)
+        if rotateGesture then
+          table.insert(gestures, rotateGesture)
+        end
+      end
+    end
+  elseif event.type == "touchrelease" then
+    local touch = self._touches[touchId]
+    if touch then
+      touch.phase = "ended"
+
+      -- Finalize gesture detection
+      local tapGesture = self:_detectTapEnded(touchId, event)
+      if tapGesture then
+        table.insert(gestures, tapGesture)
+      end
+      local swipeGesture = self:_detectSwipeEnded(touchId, event)
+      if swipeGesture then
+        table.insert(gestures, swipeGesture)
+      end
+      local panGesture = self:_detectPanEnded(touchId, event)
+      if panGesture then
+        table.insert(gestures, panGesture)
+      end
+
+      -- Cleanup touch
+      self._touches[touchId] = nil
+    end
+  elseif event.type == "touchcancel" then
+    -- Cancel all active gestures for this touch
+    self._touches[touchId] = nil
+    self:_cancelAllGestures()
+  end
+
+  return #gestures > 0 and gestures or nil
+end
+
+--- Get number of active touches
+---@return number
+function GestureRecognizer:_getTouchCount()
+  local count = 0
+  for _ in pairs(self._touches) do
+    count = count + 1
+  end
+  return count
+end
+
+--- Detect tap gesture began
+---@param touchId string
+---@param event InputEvent
+function GestureRecognizer:_detectTapBegan(touchId, event)
+  -- Tap detection happens on touch end
+  -- Just record the touch for now
+end
+
+--- Detect tap gesture ended
+---@param touchId string
+---@param event InputEvent
+function GestureRecognizer:_detectTapEnded(touchId, event)
+  local touch = self._touches[touchId]
+  if not touch then
+    return
+  end
+
+  local duration = event.timestamp - touch.startTime
+  local dx = event.x - touch.startX
+  local dy = event.y - touch.startY
+  local distance = math.sqrt(dx * dx + dy * dy)
+
+  -- Check if it's a valid tap
+  if duration < self._config.tapMaxDuration and distance < self._config.tapMaxMovement then
+    local currentTime = event.timestamp
+    local doubleTapState = self._gestureStates.doubleTap
+
+    -- Check for double-tap
+    if currentTime - doubleTapState.lastTapTime < self._config.doubleTapInterval then
+      doubleTapState.tapCount = doubleTapState.tapCount + 1
+
+      if doubleTapState.tapCount >= 2 then
+        -- Fire double-tap gesture
+        return {
+          type = GestureType.DOUBLE_TAP,
+          state = GestureState.ENDED,
+          x = event.x,
+          y = event.y,
+          timestamp = event.timestamp,
+        }
+      end
+    else
+      doubleTapState.tapCount = 1
+    end
+
+    doubleTapState.lastTapTime = currentTime
+
+    -- Fire tap gesture
+    return {
+      type = GestureType.TAP,
+      state = GestureState.ENDED,
+      x = event.x,
+      y = event.y,
+      timestamp = event.timestamp,
+    }
+  end
+end
+
+--- Detect long-press gesture began
+---@param touchId string
+---@param event InputEvent
+function GestureRecognizer:_detectLongPressBegan(touchId, event)
+  -- Long-press detection happens continuously during touch
+  self._gestureStates.longPress[touchId] = {
+    startX = event.x,
+    startY = event.y,
+    startTime = event.timestamp,
+    triggered = false,
+  }
+end
+
+--- Detect pan gesture
+---@param touchId string
+---@param event InputEvent
+---@return table? Gesture event
+function GestureRecognizer:_detectPan(touchId, event)
+  local touch = self._touches[touchId]
+  if not touch then
+    return nil
+  end
+
+  local dx = event.x - touch.startX
+  local dy = event.y - touch.startY
+  local distance = math.sqrt(dx * dx + dy * dy)
+
+  local panState = self._gestureStates.pan[touchId]
+
+  if not panState then
+    -- Check if pan should begin
+    if distance >= self._config.panMinMovement then
+      self._gestureStates.pan[touchId] = {
+        active = true,
+        lastX = touch.startX,
+        lastY = touch.startY,
+      }
+      panState = self._gestureStates.pan[touchId]
+
+      return {
+        type = GestureType.PAN,
+        state = GestureState.BEGAN,
+        x = event.x,
+        y = event.y,
+        dx = dx,
+        dy = dy,
+        timestamp = event.timestamp,
+      }
+    end
+  else
+    -- Pan is active, fire changed event
+    local panDx = event.x - panState.lastX
+    local panDy = event.y - panState.lastY
+
+    panState.lastX = event.x
+    panState.lastY = event.y
+
+    return {
+      type = GestureType.PAN,
+      state = GestureState.CHANGED,
+      x = event.x,
+      y = event.y,
+      dx = panDx,
+      dy = panDy,
+      totalDx = dx,
+      totalDy = dy,
+      timestamp = event.timestamp,
+    }
+  end
+
+  return nil
+end
+
+--- Detect pan ended
+---@param touchId string
+---@param event InputEvent
+---@return table? Gesture event
+function GestureRecognizer:_detectPanEnded(touchId, event)
+  local panState = self._gestureStates.pan[touchId]
+  if panState and panState.active then
+    self._gestureStates.pan[touchId] = nil
+
+    local touch = self._touches[touchId]
+    local dx = event.x - touch.startX
+    local dy = event.y - touch.startY
+
+    return {
+      type = GestureType.PAN,
+      state = GestureState.ENDED,
+      x = event.x,
+      y = event.y,
+      dx = dx,
+      dy = dy,
+      timestamp = event.timestamp,
+    }
+  end
+
+  return nil
+end
+
+--- Detect swipe gesture
+---@param touchId string
+---@param event InputEvent
+function GestureRecognizer:_detectSwipe(touchId, event)
+  -- Swipe detection happens on touch end
+end
+
+--- Detect swipe ended
+---@param touchId string
+---@param event InputEvent
+---@return table? Gesture event
+function GestureRecognizer:_detectSwipeEnded(touchId, event)
+  local touch = self._touches[touchId]
+  if not touch then
+    return nil
+  end
+
+  local duration = event.timestamp - touch.startTime
+  local dx = event.x - touch.startX
+  local dy = event.y - touch.startY
+  local distance = math.sqrt(dx * dx + dy * dy)
+
+  -- Check if it's a valid swipe
+  if distance >= self._config.swipeMinDistance and duration <= self._config.swipeMaxDuration then
+    local velocity = distance / duration
+
+    if velocity >= self._config.swipeMinVelocity then
+      -- Determine swipe direction
+      local angle = math.atan2(dy, dx)
+      local direction = "right"
+
+      if angle >= -math.pi / 4 and angle < math.pi / 4 then
+        direction = "right"
+      elseif angle >= math.pi / 4 and angle < 3 * math.pi / 4 then
+        direction = "down"
+      elseif angle >= -3 * math.pi / 4 and angle < -math.pi / 4 then
+        direction = "up"
+      else
+        direction = "left"
+      end
+
+      return {
+        type = GestureType.SWIPE,
+        state = GestureState.ENDED,
+        x = event.x,
+        y = event.y,
+        dx = dx,
+        dy = dy,
+        direction = direction,
+        velocity = velocity,
+        timestamp = event.timestamp,
+      }
+    end
+  end
+
+  return nil
+end
+
+--- Detect pinch gesture
+---@param event InputEvent
+---@return table? Gesture event
+function GestureRecognizer:_detectPinch(event)
+  -- Get two touches for pinch
+  local touches = {}
+  for touchId, touch in pairs(self._touches) do
+    table.insert(touches, { id = touchId, touch = touch })
+    if #touches >= 2 then
+      break
+    end
+  end
+
+  if #touches < 2 then
+    return nil
+  end
+
+  local t1 = touches[1].touch
+  local t2 = touches[2].touch
+
+  -- Calculate current distance
+  local currentDx = t2.x - t1.x
+  local currentDy = t2.y - t1.y
+  local currentDistance = math.sqrt(currentDx * currentDx + currentDy * currentDy)
+
+  -- Calculate initial distance
+  local initialDx = t2.startX - t1.startX
+  local initialDy = t2.startY - t1.startY
+  local initialDistance = math.sqrt(initialDx * initialDx + initialDy * initialDy)
+
+  if initialDistance == 0 then
+    return nil
+  end
+
+  -- Calculate scale
+  local scale = currentDistance / initialDistance
+  local pinchState = self._gestureStates.pinch
+
+  if not pinchState.active then
+    -- Check if pinch should begin
+    if math.abs(scale - 1.0) >= self._config.pinchMinScaleChange then
+      pinchState.active = true
+      pinchState.initialScale = scale
+      pinchState.lastScale = scale
+
+      -- Calculate center point
+      local centerX = (t1.x + t2.x) / 2
+      local centerY = (t1.y + t2.y) / 2
+
+      return {
+        type = GestureType.PINCH,
+        state = GestureState.BEGAN,
+        scale = scale,
+        centerX = centerX,
+        centerY = centerY,
+        timestamp = event.timestamp,
+      }
+    end
+  else
+    -- Pinch is active, fire changed event
+    local centerX = (t1.x + t2.x) / 2
+    local centerY = (t1.y + t2.y) / 2
+
+    local scaleChange = scale - pinchState.lastScale
+    pinchState.lastScale = scale
+
+    return {
+      type = GestureType.PINCH,
+      state = GestureState.CHANGED,
+      scale = scale,
+      scaleChange = scaleChange,
+      centerX = centerX,
+      centerY = centerY,
+      timestamp = event.timestamp,
+    }
+  end
+
+  return nil
+end
+
+--- Detect rotate gesture
+---@param event InputEvent
+---@return table? Gesture event
+function GestureRecognizer:_detectRotate(event)
+  -- Get two touches for rotation
+  local touches = {}
+  for touchId, touch in pairs(self._touches) do
+    table.insert(touches, { id = touchId, touch = touch })
+    if #touches >= 2 then
+      break
+    end
+  end
+
+  if #touches < 2 then
+    return nil
+  end
+
+  local t1 = touches[1].touch
+  local t2 = touches[2].touch
+
+  -- Calculate current angle
+  local currentAngle = math.atan2(t2.y - t1.y, t2.x - t1.x)
+
+  -- Calculate initial angle
+  local initialAngle = math.atan2(t2.startY - t1.startY, t2.startX - t1.startX)
+
+  -- Calculate rotation (in degrees)
+  local rotation = (currentAngle - initialAngle) * 180 / math.pi
+
+  local rotateState = self._gestureStates.rotate
+
+  if not rotateState.active then
+    -- Check if rotation should begin
+    if math.abs(rotation) >= self._config.rotateMinAngleChange then
+      rotateState.active = true
+      rotateState.initialRotation = rotation
+      rotateState.lastRotation = rotation
+
+      -- Calculate center point
+      local centerX = (t1.x + t2.x) / 2
+      local centerY = (t1.y + t2.y) / 2
+
+      return {
+        type = GestureType.ROTATE,
+        state = GestureState.BEGAN,
+        rotation = rotation,
+        centerX = centerX,
+        centerY = centerY,
+        timestamp = event.timestamp,
+      }
+    end
+  else
+    -- Rotation is active, fire changed event
+    local centerX = (t1.x + t2.x) / 2
+    local centerY = (t1.y + t2.y) / 2
+
+    local rotationChange = rotation - rotateState.lastRotation
+    rotateState.lastRotation = rotation
+
+    return {
+      type = GestureType.ROTATE,
+      state = GestureState.CHANGED,
+      rotation = rotation,
+      rotationChange = rotationChange,
+      centerX = centerX,
+      centerY = centerY,
+      timestamp = event.timestamp,
+    }
+  end
+
+  return nil
+end
+
+--- Cancel all active gestures
+function GestureRecognizer:_cancelAllGestures()
+  for gestureType, state in pairs(self._gestureStates) do
+    if type(state) == "table" and state.active then
+      state.active = false
+    end
+  end
+end
+
+--- Reset gesture recognizer state
+function GestureRecognizer:reset()
+  self._touches = {}
+  self._gestureStates = {
+    tap = nil,
+    doubleTap = { lastTapTime = 0, tapCount = 0 },
+    longPress = {},
+    swipe = {},
+    pan = {},
+    pinch = { active = false },
+    rotate = { active = false },
+  }
+end
+
+-- Export gesture types and states
+GestureRecognizer.GestureType = GestureType
+GestureRecognizer.GestureState = GestureState
+
+return GestureRecognizer

libs/flexlove/modules/Grid.lua

@@ -0,0 +1,336 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local utils = require(modulePath .. "utils")
+local enums = utils.enums
+local Units = require(modulePath .. "Units")
+
+local Positioning = enums.Positioning
+local AlignItems = enums.AlignItems
+
+--- Grid layout with variable column widths / row heights
+--- Supports px, %, fr, auto, vw, vh, and calc track sizes
+local Grid = {}
+
+--- Parse a single track spec into {type, value}
+--- Uses the Units pipeline for standard CSS units (px, %, vw, vh, calc).
+--- Grid-specific types (fr, auto) are handled directly.
+---@param spec number|string Track specification: number (px), string ("100px", "50%", "10vw", "1fr", "auto")
+---@param availableSize number Container size for % resolution
+---@param viewportWidth number Viewport width for vw resolution
+---@param viewportHeight number Viewport height for vh resolution
+---@return table {type: "px"|"fr"|"auto", value: number}
+function Grid._parseTrack(spec, availableSize, viewportWidth, viewportHeight)
+  -- Handle calc objects (tables with _isCalc flag from FlexLove.calc())
+  if type(spec) == "table" then
+    local resolved = Units.resolve(spec, "calc", viewportWidth, viewportHeight, availableSize)
+    return { type = "px", value = resolved }
+  end
+
+  if type(spec) == "number" then
+    return { type = "px", value = spec }
+  end
+
+  if type(spec) == "string" then
+    if spec == "auto" then
+      return { type = "auto", value = 0 }
+    end
+
+    -- Check for fr unit (grid-specific, not in Units pipeline)
+    local numStr, unit = spec:match("^([%-]?[%d%.]+)(.*)$")
+    if numStr and unit == "fr" then
+      local num = tonumber(numStr)
+      if num then
+        return { type = "fr", value = num }
+      end
+    end
+
+    -- Delegate all other units to the Units pipeline (px, %, vw, vh, calc)
+    local parsedVal, parsedUnit = Units.parse(spec)
+    local resolved = Units.resolve(parsedVal, parsedUnit, viewportWidth, viewportHeight, availableSize)
+    return { type = "px", value = resolved }
+  end
+
+  -- Default: 1fr
+  return { type = "fr", value = 1 }
+end
+
+--- Build track list from gridColumns/gridRows or fall back to equal 1fr tracks
+---@param spec number|table? Track count (number = equal 1fr tracks) or array of track specs (e.g., {"1fr", "2fr", "100px"})
+---@param availableSize number Container size for % resolution
+---@param viewportWidth number Viewport width for vw resolution
+---@param viewportHeight number Viewport height for vh resolution
+---@return table Array of {type, value} track descriptors
+function Grid._buildTracks(spec, availableSize, viewportWidth, viewportHeight)
+  if type(spec) == "table" and #spec > 0 then
+    local tracks = {}
+    for i, s in ipairs(spec) do
+      tracks[i] = Grid._parseTrack(s, availableSize, viewportWidth, viewportHeight)
+    end
+    return tracks
+  end
+  -- Fallback: equal 1fr tracks
+  local count = (type(spec) == "number" and spec > 0) and spec or 1
+  local tracks = {}
+  for i = 1, count do
+    tracks[i] = { type = "fr", value = 1 }
+  end
+  return tracks
+end
+
+--- Measure intrinsic content sizes for auto tracks
+--- Maps children to their tracks and computes each child's max-content contribution.
+--- For children with explicit dimensions (units unit ~= "auto"), uses the original
+--- explicit size. For auto-sized children, uses calculated content size.
+--- Stores the max per auto track. Matches CSS Grid auto sizing where tracks size
+--- to the max-content contribution of their grid items.
+---@param tracks table Array of {type, value} track descriptors
+---@param children table Array of grid child elements
+---@param axis "width"|"height" Dimension axis to measure
+function Grid._measureAutoTracks(tracks, children, axis)
+  local trackSizes = {}
+  local numTracks = #tracks
+
+  for i, child in ipairs(children) do
+    local index = i - 1
+    local trackIdx = (index % numTracks) + 1
+
+    local intrinsicSize
+    if axis == "width" then
+      local unit = child.units and child.units.width and child.units.width.unit
+      if unit and unit ~= "auto" then
+        -- Explicit width: use original value + padding (not stretched border-box)
+        intrinsicSize = (child.units.width.value or 0) + child.padding.left + child.padding.right
+      else
+        -- Auto-sized: use calculated content size
+        intrinsicSize = child:calculateAutoWidth()
+      end
+    else
+      local unit = child.units and child.units.height and child.units.height.unit
+      if unit and unit ~= "auto" then
+        intrinsicSize = (child.units.height.value or 0) + child.padding.top + child.padding.bottom
+      else
+        intrinsicSize = child:calculateAutoHeight()
+      end
+    end
+
+    if intrinsicSize > 0 then
+      trackSizes[trackIdx] = math.max(trackSizes[trackIdx] or 0, intrinsicSize)
+    end
+  end
+
+  -- Apply measured sizes to auto tracks
+  for i, track in ipairs(tracks) do
+    if track.type == "auto" and trackSizes[i] then
+      track.value = trackSizes[i]
+    end
+  end
+end
+
+--- Resolve track sizes: auto (content) first, then px (fixed), then fr (remaining)
+--- CSS Grid algorithm:
+--- 1. auto tracks size to their content (max-content) — measured by _measureAutoTracks
+--- 2. px tracks consume their fixed size
+--- 3. fr tracks consume remaining free space proportionally
+--- 4. If no fr tracks exist, auto tracks share remaining space equally
+--- Mutates tracks in-place, converting all to {type="px", value=number}
+---@param tracks table Array of {type, value} track descriptors
+---@param availableSize number Total space available for tracks
+---@param gap number Gap between tracks
+function Grid._resolveTracks(tracks, availableSize, gap)
+  local count = #tracks
+  local totalGaps = (count > 1 and (count - 1) * gap) or 0
+  local remaining = math.max(0, availableSize - totalGaps)
+
+  -- Pass 1: Treat auto tracks as fixed (content-measured) and subtract
+  for _, track in ipairs(tracks) do
+    if track.type == "px" then
+      remaining = remaining - track.value
+    elseif track.type == "auto" then
+      remaining = remaining - math.max(0, track.value)
+    end
+  end
+
+  remaining = math.max(0, remaining)
+
+  -- Pass 2: Count fr shares
+  local totalFr = 0
+  local autoCount = 0
+  for _, track in ipairs(tracks) do
+    if track.type == "fr" then
+      totalFr = totalFr + track.value
+    elseif track.type == "auto" then
+      autoCount = autoCount + 1
+    end
+  end
+
+  -- Pass 3: Distribute remaining space
+  if totalFr > 0 then
+    -- fr tracks consume all remaining free space
+    local frUnit = remaining / totalFr
+    for _, track in ipairs(tracks) do
+      if track.type == "fr" then
+        track.value = frUnit * track.value
+        track.type = "px"
+      end
+    end
+  elseif autoCount > 0 then
+    -- No fr tracks: auto tracks share remaining space equally (grow beyond content)
+    local extraPerAuto = math.max(0, remaining) / autoCount
+    for _, track in ipairs(tracks) do
+      if track.type == "auto" then
+        track.value = track.value + extraPerAuto
+        track.type = "px"
+      end
+    end
+  end
+end
+
+--- Layout grid items within a grid container
+--- Supports variable column widths and row heights via gridColumns/gridRows (number or track specs)
+--- Falls back to equal-sized 1fr tracks when nil
+---@param element Element -- Grid container element
+function Grid.layoutGridItems(element)
+  -- Calculate space reserved by absolutely positioned siblings
+  local reservedLeft = 0
+  local reservedRight = 0
+  local reservedTop = 0
+  local reservedBottom = 0
+
+  for _, child in ipairs(element.children) do
+    -- Only consider absolutely positioned children with explicit positioning and display != false
+    if child.positioning == Positioning.ABSOLUTE and child._explicitlyAbsolute and child.display ~= false then
+      -- BORDER-BOX MODEL: Use border-box dimensions for space calculations
+      local childBorderBoxWidth = child:getBorderBoxWidth()
+      local childBorderBoxHeight = child:getBorderBoxHeight()
+
+      if child.left then
+        reservedLeft = math.max(reservedLeft, child.left + childBorderBoxWidth)
+      end
+      if child.right then
+        reservedRight = math.max(reservedRight, child.right + childBorderBoxWidth)
+      end
+      if child.top then
+        reservedTop = math.max(reservedTop, child.top + childBorderBoxHeight)
+      end
+      if child.bottom then
+        reservedBottom = math.max(reservedBottom, child.bottom + childBorderBoxHeight)
+      end
+    end
+  end
+
+  -- Calculate available space (accounting for padding and reserved space)
+  -- BORDER-BOX MODEL: element.width and element.height are already content dimensions
+  local availableWidth = math.max(0, element.width - reservedLeft - reservedRight)
+  local availableHeight = math.max(0, element.height - reservedTop - reservedBottom)
+
+  -- Get gaps
+  local columnGap = element.columnGap or 0
+  local rowGap = element.rowGap or 0
+
+  -- Collect grid children (exclude explicitly absolute and display=false)
+  local gridChildren = {}
+  for _, child in ipairs(element.children) do
+    if not (child.positioning == Positioning.ABSOLUTE and child._explicitlyAbsolute) and child.display ~= false then
+      table.insert(gridChildren, child)
+    end
+  end
+
+  -- Get viewport dimensions for unit resolution (vw, vh, %)
+  local vpw, vph = Units.getViewport()
+
+  -- Build tracks, measure auto tracks by content, then resolve sizes
+  local colTracks = Grid._buildTracks(element.gridColumns, availableWidth, vpw, vph)
+  local rowTracks = Grid._buildTracks(element.gridRows, availableHeight, vpw, vph)
+
+  Grid._measureAutoTracks(colTracks, gridChildren, "width")
+  Grid._measureAutoTracks(rowTracks, gridChildren, "height")
+
+  Grid._resolveTracks(colTracks, availableWidth, columnGap)
+  Grid._resolveTracks(rowTracks, availableHeight, rowGap)
+
+  -- Compute column start positions (for positioning)
+  local colStarts = {}
+  local currentX = element.x + element.padding.left + reservedLeft
+  for col = 1, #colTracks do
+    colStarts[col] = currentX
+    currentX = currentX + colTracks[col].value + columnGap
+  end
+
+  local rowStarts = {}
+  local currentY = element.y + element.padding.top + reservedTop
+  for row = 1, #rowTracks do
+    rowStarts[row] = currentY
+    currentY = currentY + rowTracks[row].value + rowGap
+  end
+
+  local effectiveAlignItems = element.alignItems or AlignItems.STRETCH
+
+  for i, child in ipairs(gridChildren) do
+    -- Calculate row and column (0-indexed for calculation)
+    local index = i - 1
+    local col = index % #colTracks
+    local row = math.floor(index / #colTracks)
+
+    if row >= #rowTracks then
+      break
+    end
+
+    -- Get resolved cell position and size
+    local colIdx = col + 1
+    local rowIdx = row + 1
+    local cellX = colStarts[colIdx]
+    local cellY = rowStarts[rowIdx]
+    local cellWidth = colTracks[colIdx].value
+    local cellHeight = rowTracks[rowIdx].value
+
+    -- Apply alignment within grid cell (default to stretch)
+    -- BORDER-BOX MODEL: Set border-box dimensions, content area adjusts automatically
+    if effectiveAlignItems == AlignItems.STRETCH or effectiveAlignItems == "stretch" then
+      child.x = cellX
+      child.y = cellY
+      child._borderBoxWidth = cellWidth
+      child._borderBoxHeight = cellHeight
+      child.width = math.max(0, cellWidth - child.padding.left - child.padding.right)
+      child.height = math.max(0, cellHeight - child.padding.top - child.padding.bottom)
+      -- Disable auto-sizing when stretched by grid
+      child.autosizing.width = false
+      child.autosizing.height = false
+    elseif effectiveAlignItems == AlignItems.CENTER or effectiveAlignItems == "center" then
+      local childBorderBoxWidth = child:getBorderBoxWidth()
+      local childBorderBoxHeight = child:getBorderBoxHeight()
+      child.x = cellX + (cellWidth - childBorderBoxWidth) / 2
+      child.y = cellY + (cellHeight - childBorderBoxHeight) / 2
+    elseif
+      effectiveAlignItems == AlignItems.FLEX_START
+      or effectiveAlignItems == "flex-start"
+      or effectiveAlignItems == "start"
+    then
+      child.x = cellX
+      child.y = cellY
+    elseif
+      effectiveAlignItems == AlignItems.FLEX_END
+      or effectiveAlignItems == "flex-end"
+      or effectiveAlignItems == "end"
+    then
+      local childBorderBoxWidth = child:getBorderBoxWidth()
+      local childBorderBoxHeight = child:getBorderBoxHeight()
+      child.x = cellX + cellWidth - childBorderBoxWidth
+      child.y = cellY + cellHeight - childBorderBoxHeight
+    else
+      child.x = cellX
+      child.y = cellY
+      child._borderBoxWidth = cellWidth
+      child._borderBoxHeight = cellHeight
+      child.width = math.max(0, cellWidth - child.padding.left - child.padding.right)
+      child.height = math.max(0, cellHeight - child.padding.top - child.padding.bottom)
+      -- Disable auto-sizing when stretched by grid
+      child.autosizing.width = false
+      child.autosizing.height = false
+    end
+
+    if #child.children > 0 then
+      child:layoutChildren()
+    end
+  end
+end
+
+return Grid

libs/flexlove/modules/ImageCache.lua

@@ -0,0 +1,160 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+local utils = req("utils")
+
+-- ErrorHandler will be injected via init
+local ErrorHandler = nil
+
+---@class ImageCache
+---@field _cache table<string, {image: love.Image, imageData: love.ImageData?}>
+local ImageCache = {}
+ImageCache._cache = {}
+
+--- Initialize ImageCache with dependencies
+---@param deps table Dependencies table with ErrorHandler
+function ImageCache.init(deps)
+  if deps and deps.ErrorHandler then
+    ErrorHandler = deps.ErrorHandler
+  end
+end
+
+--- Load an image from file path with caching
+--- Returns cached image if already loaded, otherwise loads and caches it
+---@param imagePath string -- Path to image file
+---@param loadImageData boolean? -- Optional: also load ImageData for pixel access (default: false)
+---@return love.Image|nil -- Image object or nil on error
+---@return string|nil -- Error message if loading failed
+function ImageCache.load(imagePath, loadImageData)
+  if not imagePath or type(imagePath) ~= "string" or imagePath == "" then
+    return nil, "Invalid image path: path must be a non-empty string"
+  end
+
+  local normalizedPath = utils.normalizePath(imagePath)
+
+  if ImageCache._cache[normalizedPath] then
+    return ImageCache._cache[normalizedPath].image, nil
+  end
+
+  local success, imageOrError = pcall(love.graphics.newImage, normalizedPath)
+  if not success then
+    if ErrorHandler then
+      ErrorHandler:warn("ImageCache", "RES_004", {
+        resourceType = "image",
+        path = imagePath,
+        error = tostring(imageOrError),
+      })
+    end
+    return nil, string.format("Failed to load image '%s': %s", imagePath, tostring(imageOrError))
+  end
+
+  local image = imageOrError
+  local imgData = nil
+
+  if loadImageData then
+    local dataSuccess, dataOrError = pcall(love.image.newImageData, normalizedPath)
+    if dataSuccess then
+      imgData = dataOrError
+    elseif ErrorHandler then
+      ErrorHandler:warn("ImageCache", "RES_004", {
+        resourceType = "image data",
+        path = imagePath,
+        error = tostring(dataOrError),
+      })
+    end
+  end
+
+  ImageCache._cache[normalizedPath] = {
+    image = image,
+    imageData = imgData,
+  }
+
+  return image, nil
+end
+
+--- Get a cached image without loading
+---@param imagePath string -- Path to image file
+---@return love.Image|nil -- Cached image or nil if not found
+function ImageCache.get(imagePath)
+  if not imagePath or type(imagePath) ~= "string" then
+    return nil
+  end
+
+  local normalizedPath = utils.normalizePath(imagePath)
+  local cached = ImageCache._cache[normalizedPath]
+  return cached and cached.image or nil
+end
+
+--- Get cached ImageData for an image
+---@param imagePath string -- Path to image file
+---@return love.ImageData|nil -- Cached ImageData or nil if not found
+function ImageCache.getImageData(imagePath)
+  if not imagePath or type(imagePath) ~= "string" then
+    return nil
+  end
+
+  local normalizedPath = utils.normalizePath(imagePath)
+  local cached = ImageCache._cache[normalizedPath]
+  return cached and cached.imageData or nil
+end
+
+--- Remove a specific image from cache
+---@param imagePath string -- Path to image file to remove
+---@return boolean -- True if image was removed, false if not found
+function ImageCache.remove(imagePath)
+  if not imagePath or type(imagePath) ~= "string" then
+    return false
+  end
+
+  local normalizedPath = utils.normalizePath(imagePath)
+  if ImageCache._cache[normalizedPath] then
+    local cached = ImageCache._cache[normalizedPath]
+    if cached.image then
+      cached.image:release()
+    end
+    if cached.imageData then
+      cached.imageData:release()
+    end
+    ImageCache._cache[normalizedPath] = nil
+    return true
+  end
+  return false
+end
+
+--- Clear all cached images
+function ImageCache.clear()
+  for path, cached in pairs(ImageCache._cache) do
+    if cached.image then
+      cached.image:release()
+    end
+    if cached.imageData then
+      cached.imageData:release()
+    end
+  end
+  ImageCache._cache = {}
+end
+
+--- Get cache statistics
+---@return {count: number, memoryEstimate: number} -- Cache stats
+function ImageCache.getStats()
+  local count = 0
+  local memoryEstimate = 0
+
+  for path, cached in pairs(ImageCache._cache) do
+    count = count + 1
+    if cached.image then
+      local w, h = cached.image:getDimensions()
+      -- Estimate: 4 bytes per pixel (RGBA)
+      memoryEstimate = memoryEstimate + (w * h * 4)
+    end
+  end
+
+  return {
+    count = count,
+    memoryEstimate = memoryEstimate,
+  }
+end
+
+return ImageCache

libs/flexlove/modules/ImageRenderer.lua

@@ -0,0 +1,380 @@
+---@class ImageRenderer
+local ImageRenderer = {}
+
+-- ErrorHandler and utils will be injected via init
+local ErrorHandler = nil
+local utils = nil
+
+--- Initialize ImageRenderer with dependencies
+---@param deps table Dependencies table with ErrorHandler and utils
+function ImageRenderer.init(deps)
+  if deps and deps.ErrorHandler then
+    ErrorHandler = deps.ErrorHandler
+  end
+  if deps and deps.utils then
+    utils = deps.utils
+  end
+end
+
+--- Calculate rendering parameters for object-fit modes
+--- Returns source and destination rectangles for rendering
+---@param imageWidth number -- Natural width of the image
+---@param imageHeight number -- Natural height of the image
+---@param boundsWidth number -- Width of the bounds to fit within
+---@param boundsHeight number -- Height of the bounds to fit within
+---@param fitMode string? -- One of: "fill", "contain", "cover", "scale-down", "none" (default: "fill")
+---@param objectPosition string? -- Position like "center center", "top left", "50% 50%" (default: "center center")
+---@return {sx: number, sy: number, sw: number, sh: number, dx: number, dy: number, dw: number, dh: number, scaleX: number, scaleY: number}
+function ImageRenderer.calculateFit(imageWidth, imageHeight, boundsWidth, boundsHeight, fitMode, objectPosition)
+  fitMode = fitMode or "fill"
+  objectPosition = objectPosition or "center center"
+
+  if imageWidth <= 0 or imageHeight <= 0 or boundsWidth <= 0 or boundsHeight <= 0 then
+    ErrorHandler:error("ImageRenderer", "VAL_002", {
+      imageWidth = imageWidth,
+      imageHeight = imageHeight,
+      boundsWidth = boundsWidth,
+      boundsHeight = boundsHeight,
+    })
+  end
+
+  local result = {
+    sx = 0, -- Source X
+    sy = 0, -- Source Y
+    sw = imageWidth, -- Source width
+    sh = imageHeight, -- Source height
+    dx = 0, -- Destination X
+    dy = 0, -- Destination Y
+    dw = boundsWidth, -- Destination width
+    dh = boundsHeight, -- Destination height
+    scaleX = 1, -- Scale factor X
+    scaleY = 1, -- Scale factor Y
+  }
+
+  if fitMode == "fill" then
+    -- Stretch to fill bounds (may distort)
+    result.scaleX = boundsWidth / imageWidth
+    result.scaleY = boundsHeight / imageHeight
+    result.dw = boundsWidth
+    result.dh = boundsHeight
+  elseif fitMode == "contain" then
+    -- Scale to fit within bounds (preserves aspect ratio)
+    local scale = math.min(boundsWidth / imageWidth, boundsHeight / imageHeight)
+    result.scaleX = scale
+    result.scaleY = scale
+    result.dw = imageWidth * scale
+    result.dh = imageHeight * scale
+
+    -- Apply object-position for letterbox alignment
+    local posX, posY = ImageRenderer._parsePosition(objectPosition)
+    result.dx = (boundsWidth - result.dw) * posX
+    result.dy = (boundsHeight - result.dh) * posY
+  elseif fitMode == "cover" then
+    -- Scale to cover bounds (preserves aspect ratio, may crop)
+    local scale = math.max(boundsWidth / imageWidth, boundsHeight / imageHeight)
+    result.scaleX = scale
+    result.scaleY = scale
+
+    local scaledWidth = imageWidth * scale
+    local scaledHeight = imageHeight * scale
+
+    -- Apply object-position for crop alignment
+    local posX, posY = ImageRenderer._parsePosition(objectPosition)
+
+    -- Calculate which part of the scaled image to show
+    local cropX = (scaledWidth - boundsWidth) * posX
+    local cropY = (scaledHeight - boundsHeight) * posY
+
+    -- Convert back to source coordinates
+    result.sx = cropX / scale
+    result.sy = cropY / scale
+    result.sw = boundsWidth / scale
+    result.sh = boundsHeight / scale
+
+    result.dx = 0
+    result.dy = 0
+    result.dw = boundsWidth
+    result.dh = boundsHeight
+  elseif fitMode == "none" then
+    -- Use natural size (no scaling)
+    result.scaleX = 1
+    result.scaleY = 1
+    result.dw = imageWidth
+    result.dh = imageHeight
+
+    -- Apply object-position
+    local posX, posY = ImageRenderer._parsePosition(objectPosition)
+    result.dx = (boundsWidth - imageWidth) * posX
+    result.dy = (boundsHeight - imageHeight) * posY
+  elseif fitMode == "scale-down" then
+    -- Use none or contain, whichever is smaller
+    if imageWidth <= boundsWidth and imageHeight <= boundsHeight then
+      -- Image fits naturally, use "none"
+      return ImageRenderer.calculateFit(imageWidth, imageHeight, boundsWidth, boundsHeight, "none", objectPosition)
+    else
+      -- Image too large, use "contain"
+      return ImageRenderer.calculateFit(imageWidth, imageHeight, boundsWidth, boundsHeight, "contain", objectPosition)
+    end
+  else
+    ErrorHandler:warn("ImageRenderer", "VAL_007", {
+      fitMode = fitMode,
+      fallback = "fill",
+    })
+    -- Use 'fill' as fallback
+    return ImageRenderer.calculateFit(imageWidth, imageHeight, boundsWidth, boundsHeight, "fill", objectPosition)
+  end
+
+  return result
+end
+
+--- Parse object-position string into normalized coordinates (0-1)
+--- Supports keywords (center, top, bottom, left, right) and percentages
+---@param position string -- Position string like "center center", "top left", "50% 50%"
+---@return number, number -- Normalized X and Y positions (0-1)
+function ImageRenderer._parsePosition(position)
+  if not position or type(position) ~= "string" then
+    return 0.5, 0.5 -- Default to center
+  end
+
+  -- Split into X and Y components
+  local parts = {}
+  for part in position:gmatch("%S+") do
+    table.insert(parts, part:lower())
+  end
+
+  -- If only one value, use it for both axes (with special handling)
+  if #parts == 1 then
+    local val = parts[1]
+    if val == "left" or val == "right" then
+      parts = { val, "center" }
+    elseif val == "top" or val == "bottom" then
+      parts = { "center", val }
+    else
+      parts = { val, val }
+    end
+  elseif #parts == 0 then
+    return 0.5, 0.5 -- Default to center
+  end
+
+  local function parseValue(val)
+    -- Handle keywords
+    if val == "center" then
+      return 0.5
+    elseif val == "left" or val == "top" then
+      return 0
+    elseif val == "right" or val == "bottom" then
+      return 1
+    end
+
+    -- Handle percentages
+    local percent = val:match("^([%d%.]+)%%$")
+    if percent then
+      return tonumber(percent) / 100
+    end
+
+    -- Handle plain numbers (treat as percentage)
+    local num = tonumber(val)
+    if num then
+      return num / 100
+    end
+
+    -- Invalid value, default to center
+    return 0.5
+  end
+
+  local x = parseValue(parts[1])
+  local y = parseValue(parts[2] or parts[1])
+
+  -- Clamp to 0-1 range
+  x = math.max(0, math.min(1, x))
+  y = math.max(0, math.min(1, y))
+
+  return x, y
+end
+
+--- Draw an image with specified object-fit mode
+---@param image love.Image -- Image to draw
+---@param x number -- X position of bounds
+---@param y number -- Y position of bounds
+---@param width number -- Width of bounds
+---@param height number -- Height of bounds
+---@param fitMode string? -- Object-fit mode (default: "fill")
+---@param objectPosition string? -- Object-position (default: "center center")
+---@param opacity number? -- Opacity 0-1 (default: 1)
+---@param tintColor Color? -- Color to tint the image (default: white/no tint)
+function ImageRenderer.draw(image, x, y, width, height, fitMode, objectPosition, opacity, tintColor)
+  if not image then
+    return -- Nothing to draw
+  end
+
+  opacity = opacity or 1
+  fitMode = fitMode or "fill"
+  objectPosition = objectPosition or "center center"
+
+  local imgWidth, imgHeight = image:getDimensions()
+  local params = ImageRenderer.calculateFit(imgWidth, imgHeight, width, height, fitMode, objectPosition)
+
+  -- Save current color
+  local r, g, b, a = love.graphics.getColor()
+
+  -- Apply opacity and tint
+  if tintColor then
+    love.graphics.setColor(tintColor.r, tintColor.g, tintColor.b, tintColor.a * opacity)
+  else
+    love.graphics.setColor(1, 1, 1, opacity)
+  end
+
+  -- Draw image
+  if params.sx ~= 0 or params.sy ~= 0 or params.sw ~= imgWidth or params.sh ~= imgHeight then
+    -- Need to use a quad for cropping
+    local quad = love.graphics.newQuad(params.sx, params.sy, params.sw, params.sh, imgWidth, imgHeight)
+    love.graphics.draw(image, quad, x + params.dx, y + params.dy, 0, params.dw / params.sw, params.dh / params.sh)
+  else
+    -- Simple draw with scaling
+    love.graphics.draw(image, x + params.dx, y + params.dy, 0, params.scaleX, params.scaleY)
+  end
+
+  -- Restore color
+  love.graphics.setColor(r, g, b, a)
+end
+
+--- Draw an image with tiling/repeat mode
+---@param image love.Image -- Image to draw
+---@param x number -- X position of bounds
+---@param y number -- Y position of bounds
+---@param width number -- Width of bounds
+---@param height number -- Height of bounds
+---@param repeatMode string? -- Repeat mode: "repeat", "repeat-x", "repeat-y", "no-repeat", "space", "round" (default: "no-repeat")
+---@param opacity number? -- Opacity 0-1 (default: 1)
+---@param tintColor Color? -- Color to tint the image (default: white/no tint)
+function ImageRenderer.drawTiled(image, x, y, width, height, repeatMode, opacity, tintColor)
+  if not image then
+    return -- Nothing to draw
+  end
+
+  opacity = opacity or 1
+  repeatMode = repeatMode or "no-repeat"
+
+  local imgWidth, imgHeight = image:getDimensions()
+
+  -- Save current color
+  local r, g, b, a = love.graphics.getColor()
+
+  -- Apply opacity and tint
+  if tintColor then
+    love.graphics.setColor(tintColor.r, tintColor.g, tintColor.b, tintColor.a * opacity)
+  else
+    love.graphics.setColor(1, 1, 1, opacity)
+  end
+
+  if repeatMode == "no-repeat" then
+    -- Just draw once, no tiling
+    love.graphics.draw(image, x, y)
+  elseif repeatMode == "repeat" then
+    -- Tile in both directions
+    local tilesX = math.ceil(width / imgWidth)
+    local tilesY = math.ceil(height / imgHeight)
+
+    for tileY = 0, tilesY - 1 do
+      for tileX = 0, tilesX - 1 do
+        local drawX = x + (tileX * imgWidth)
+        local drawY = y + (tileY * imgHeight)
+
+        -- Calculate how much of the tile to draw (for partial tiles at edges)
+        local drawWidth = math.min(imgWidth, width - (tileX * imgWidth))
+        local drawHeight = math.min(imgHeight, height - (tileY * imgHeight))
+
+        if drawWidth < imgWidth or drawHeight < imgHeight then
+          -- Use quad for partial tile
+          local quad = love.graphics.newQuad(0, 0, drawWidth, drawHeight, imgWidth, imgHeight)
+          love.graphics.draw(image, quad, drawX, drawY)
+        else
+          -- Draw full tile
+          love.graphics.draw(image, drawX, drawY)
+        end
+      end
+    end
+  elseif repeatMode == "repeat-x" then
+    -- Tile horizontally only
+    local tilesX = math.ceil(width / imgWidth)
+
+    for tileX = 0, tilesX - 1 do
+      local drawX = x + (tileX * imgWidth)
+      local drawWidth = math.min(imgWidth, width - (tileX * imgWidth))
+
+      if drawWidth < imgWidth then
+        -- Use quad for partial tile
+        local quad = love.graphics.newQuad(0, 0, drawWidth, imgHeight, imgWidth, imgHeight)
+        love.graphics.draw(image, quad, drawX, y)
+      else
+        -- Draw full tile
+        love.graphics.draw(image, drawX, y)
+      end
+    end
+  elseif repeatMode == "repeat-y" then
+    -- Tile vertically only
+    local tilesY = math.ceil(height / imgHeight)
+
+    for tileY = 0, tilesY - 1 do
+      local drawY = y + (tileY * imgHeight)
+      local drawHeight = math.min(imgHeight, height - (tileY * imgHeight))
+
+      if drawHeight < imgHeight then
+        -- Use quad for partial tile
+        local quad = love.graphics.newQuad(0, 0, imgWidth, drawHeight, imgWidth, imgHeight)
+        love.graphics.draw(image, quad, x, drawY)
+      else
+        -- Draw full tile
+        love.graphics.draw(image, x, drawY)
+      end
+    end
+  elseif repeatMode == "space" then
+    -- Distribute tiles with even spacing
+    local tilesX = math.floor(width / imgWidth)
+    local tilesY = math.floor(height / imgHeight)
+
+    if tilesX < 1 then
+      tilesX = 1
+    end
+    if tilesY < 1 then
+      tilesY = 1
+    end
+
+    local spaceX = tilesX > 1 and (width - (tilesX * imgWidth)) / (tilesX - 1) or 0
+    local spaceY = tilesY > 1 and (height - (tilesY * imgHeight)) / (tilesY - 1) or 0
+
+    for tileY = 0, tilesY - 1 do
+      for tileX = 0, tilesX - 1 do
+        local drawX = x + (tileX * (imgWidth + spaceX))
+        local drawY = y + (tileY * (imgHeight + spaceY))
+        love.graphics.draw(image, drawX, drawY)
+      end
+    end
+  elseif repeatMode == "round" then
+    -- Scale tiles to fit bounds exactly
+    local tilesX = math.max(1, utils.round(width / imgWidth))
+    local tilesY = math.max(1, utils.round(height / imgHeight))
+
+    local scaleX = width / (tilesX * imgWidth)
+    local scaleY = height / (tilesY * imgHeight)
+
+    for tileY = 0, tilesY - 1 do
+      for tileX = 0, tilesX - 1 do
+        local drawX = x + (tileX * imgWidth * scaleX)
+        local drawY = y + (tileY * imgHeight * scaleY)
+        love.graphics.draw(image, drawX, drawY, 0, scaleX, scaleY)
+      end
+    end
+  else
+    ErrorHandler:warn("ImageRenderer", "VAL_007", {
+      repeatMode = repeatMode,
+      fallback = "no-repeat",
+    })
+    love.graphics.draw(image, x, y)
+  end
+
+  -- Restore color
+  love.graphics.setColor(r, g, b, a)
+end
+
+return ImageRenderer

libs/flexlove/modules/ImageScaler.lua

@@ -0,0 +1,174 @@
+-- ====================
+-- ImageScaler
+-- ====================
+
+local ImageScaler = {}
+
+-- ErrorHandler will be injected via init
+local ErrorHandler = nil
+
+--- Initialize ImageScaler with dependencies
+---@param deps table Dependencies table with ErrorHandler
+function ImageScaler.init(deps)
+  if deps and deps.ErrorHandler then
+    ErrorHandler = deps.ErrorHandler
+  end
+end
+
+--- Scale an ImageData region using nearest-neighbor sampling
+--- Produces sharp, pixelated scaling - ideal for pixel art
+---@param sourceImageData love.ImageData -- Source image data
+---@param srcX number -- Source region X (0-based)
+---@param srcY number -- Source region Y (0-based)
+---@param srcW number -- Source region width
+---@param srcH number -- Source region height
+---@param destW number -- Destination width
+---@param destH number -- Destination height
+---@return love.ImageData -- Scaled image data
+function ImageScaler.scaleNearest(sourceImageData, srcX, srcY, srcW, srcH, destW, destH)
+  if not sourceImageData then
+    ErrorHandler:error("ImageScaler", "VAL_001", {
+      parameter = "sourceImageData",
+    })
+  end
+
+  if srcW <= 0 or srcH <= 0 or destW <= 0 or destH <= 0 then
+    ErrorHandler:warn("ImageScaler", "VAL_002", {
+      srcW = srcW,
+      srcH = srcH,
+      destW = destW,
+      destH = destH,
+      fallback = "1x1 transparent image",
+    })
+    -- Return a minimal 1x1 transparent image as fallback
+    local fallbackImageData = love.image.newImageData(1, 1)
+    fallbackImageData:setPixel(0, 0, 0, 0, 0, 0)
+    return fallbackImageData
+  end
+
+  -- Create destination ImageData
+  local destImageData = love.image.newImageData(destW, destH)
+
+  -- Calculate scale ratios (cached outside loops for performance)
+  local scaleX = srcW / destW
+  local scaleY = srcH / destH
+
+  -- Nearest-neighbor sampling
+  for destY = 0, destH - 1 do
+    for destX = 0, destW - 1 do
+      -- Calculate source pixel coordinates using floor (nearest-neighbor)
+      local srcPixelX = math.floor(destX * scaleX) + srcX
+      local srcPixelY = math.floor(destY * scaleY) + srcY
+
+      -- Clamp to source bounds (safety check)
+      srcPixelX = math.min(srcPixelX, srcX + srcW - 1)
+      srcPixelY = math.min(srcPixelY, srcY + srcH - 1)
+
+      -- Sample source pixel
+      local r, g, b, a = sourceImageData:getPixel(srcPixelX, srcPixelY)
+
+      -- Write to destination
+      destImageData:setPixel(destX, destY, r, g, b, a)
+    end
+  end
+
+  return destImageData
+end
+
+--- Linear interpolation helper
+--- Blends between two values based on interpolation factor
+---@param a number -- Start value
+---@param b number -- End value
+---@param t number -- Interpolation factor [0, 1]
+---@return number -- Interpolated value
+local function lerp(a, b, t)
+  return a + (b - a) * t
+end
+
+--- Scale an ImageData region using bilinear interpolation
+--- Produces smooth, filtered scaling - ideal for high-quality upscaling
+---@param sourceImageData love.ImageData -- Source image data
+---@param srcX number -- Source region X (0-based)
+---@param srcY number -- Source region Y (0-based)
+---@param srcW number -- Source region width
+---@param srcH number -- Source region height
+---@param destW number -- Destination width
+---@param destH number -- Destination height
+---@return love.ImageData -- Scaled image data
+function ImageScaler.scaleBilinear(sourceImageData, srcX, srcY, srcW, srcH, destW, destH)
+  if not sourceImageData then
+    ErrorHandler:error("ImageScaler", "VAL_001", {
+      parameter = "sourceImageData",
+    })
+  end
+
+  if srcW <= 0 or srcH <= 0 or destW <= 0 or destH <= 0 then
+    ErrorHandler:warn("ImageScaler", "VAL_002", {
+      srcW = srcW,
+      srcH = srcH,
+      destW = destW,
+      destH = destH,
+      fallback = "1x1 transparent image",
+    })
+    -- Return a minimal 1x1 transparent image as fallback
+    local fallbackImageData = love.image.newImageData(1, 1)
+    fallbackImageData:setPixel(0, 0, 0, 0, 0, 0)
+    return fallbackImageData
+  end
+
+  -- Create destination ImageData
+  local destImageData = love.image.newImageData(destW, destH)
+
+  -- Calculate scale ratios
+  local scaleX = srcW / destW
+  local scaleY = srcH / destH
+
+  -- Bilinear interpolation
+  for destY = 0, destH - 1 do
+    for destX = 0, destW - 1 do
+      -- Calculate fractional source position
+      local srcXf = destX * scaleX
+      local srcYf = destY * scaleY
+
+      -- Get integer coordinates for 2x2 sampling grid
+      local x0 = math.floor(srcXf)
+      local y0 = math.floor(srcYf)
+      local x1 = math.min(x0 + 1, srcW - 1)
+      local y1 = math.min(y0 + 1, srcH - 1)
+
+      -- Get fractional parts for interpolation
+      local fx = srcXf - x0
+      local fy = srcYf - y0
+
+      -- Sample 4 neighboring pixels (with source offset)
+      local r00, g00, b00, a00 = sourceImageData:getPixel(srcX + x0, srcY + y0)
+      local r10, g10, b10, a10 = sourceImageData:getPixel(srcX + x1, srcY + y0)
+      local r01, g01, b01, a01 = sourceImageData:getPixel(srcX + x0, srcY + y1)
+      local r11, g11, b11, a11 = sourceImageData:getPixel(srcX + x1, srcY + y1)
+
+      -- Interpolate horizontally (top and bottom rows)
+      local rTop = lerp(r00, r10, fx)
+      local gTop = lerp(g00, g10, fx)
+      local bTop = lerp(b00, b10, fx)
+      local aTop = lerp(a00, a10, fx)
+
+      local rBottom = lerp(r01, r11, fx)
+      local gBottom = lerp(g01, g11, fx)
+      local bBottom = lerp(b01, b11, fx)
+      local aBottom = lerp(a01, a11, fx)
+
+      -- Interpolate vertically (final result)
+      local r = lerp(rTop, rBottom, fy)
+      local g = lerp(gTop, gBottom, fy)
+      local b = lerp(bTop, bBottom, fy)
+      local a = lerp(aTop, aBottom, fy)
+
+      -- Write to destination
+      destImageData:setPixel(destX, destY, r, g, b, a)
+    end
+  end
+
+  return destImageData
+end
+
+return ImageScaler

libs/flexlove/modules/InputEvent.lua

@@ -0,0 +1,88 @@
+---@class InputEvent
+---@field type "click"|"press"|"release"|"rightclick"|"middleclick"|"drag"|"hover"|"unhover"|"touchpress"|"touchmove"|"touchrelease"|"touchcancel"
+---@field button number -- Mouse button: 1 (left), 2 (right), 3 (middle)
+---@field x number -- Mouse/Touch X position
+---@field y number -- Mouse/Touch Y position
+---@field dx number? -- Delta X from drag/touch start (only for drag/touch events)
+---@field dy number? -- Delta Y from drag/touch start (only for drag/touch events)
+---@field modifiers {shift:boolean, ctrl:boolean, alt:boolean, super:boolean}
+---@field clickCount number -- Number of clicks (for double/triple click detection)
+---@field timestamp number -- Time when event occurred
+---@field touchId string? -- Touch identifier (for multi-touch)
+---@field pressure number? -- Touch pressure (0-1, defaults to 1.0)
+---@field phase string? -- Touch phase: "began", "moved", "ended", "cancelled"
+local InputEvent = {}
+InputEvent.__index = InputEvent
+
+---@class InputEventProps
+---@field type "click"|"press"|"release"|"rightclick"|"middleclick"|"drag"|"hover"|"unhover"|"touchpress"|"touchmove"|"touchrelease"|"touchcancel"
+---@field button number
+---@field x number
+---@field y number
+---@field dx number?
+---@field dy number?
+---@field modifiers {shift:boolean, ctrl:boolean, alt:boolean, super:boolean}
+---@field clickCount number?
+---@field timestamp number?
+---@field touchId string?
+---@field pressure number?
+---@field phase string?
+
+--- Create a new input event
+---@param props InputEventProps
+---@return InputEvent
+function InputEvent.new(props)
+  local self = setmetatable({}, InputEvent)
+  self.type = props.type
+  self.button = props.button
+  self.x = props.x
+  self.y = props.y
+  self.dx = props.dx
+  self.dy = props.dy
+  self.modifiers = props.modifiers
+  self.clickCount = props.clickCount or 1
+  self.timestamp = props.timestamp or love.timer.getTime()
+
+  -- Touch-specific properties
+  self.touchId = props.touchId
+  self.pressure = props.pressure or 1.0
+  self.phase = props.phase
+
+  return self
+end
+
+--- Create an InputEvent from LÖVE touch data
+---@param id userdata Touch ID from LÖVE
+---@param x number Touch X position
+---@param y number Touch Y position
+---@param phase string Touch phase: "began", "moved", "ended", "cancelled"
+---@param pressure number? Touch pressure (0-1, defaults to 1.0)
+---@return InputEvent
+function InputEvent.fromTouch(id, x, y, phase, pressure)
+  local touchIdStr = tostring(id)
+  local eventType = "touchpress"
+  if phase == "moved" then
+    eventType = "touchmove"
+  elseif phase == "ended" then
+    eventType = "touchrelease"
+  elseif phase == "cancelled" then
+    eventType = "touchcancel"
+  end
+
+  return InputEvent.new({
+    type = eventType,
+    button = 1, -- Treat touch as left button
+    x = x,
+    y = y,
+    dx = 0,
+    dy = 0,
+    modifiers = { shift = false, ctrl = false, alt = false, super = false },
+    clickCount = 1,
+    timestamp = love.timer.getTime(),
+    touchId = touchIdStr,
+    pressure = pressure or 1.0,
+    phase = phase,
+  })
+end
+
+return InputEvent

libs/flexlove/modules/KeyboardNavigation.lua

@@ -0,0 +1,748 @@
+local packageName = ... or "KeyboardNavigation"
+local modulePath = packageName:match("(.-)[^%.]+$")
+
+local function req(name)
+  return require(modulePath .. name)
+end
+
+---@class KeyboardNavigation
+---@field config KeyboardNavigationConfig
+local KeyboardNavigation = {
+
+  config = {
+    -- Global settings
+    enabled = true,
+    debugMode = false,
+
+    -- Key bindings
+    keys = {
+      next = "tab",
+      previous = "shifttab",
+      up = "up",
+      down = "down",
+      left = "left",
+      right = "right",
+      activate = { "return", "space" },
+      dismiss = "escape",
+      toggleDebug = "f12",
+      inspect = "i",
+    },
+
+    -- Navigation behavior
+    wrapAround = true,
+    directionalNavigation = true,
+    focusVisible = true,
+    autofocusOnCreate = false,
+
+    --- Drop focus after pressing Enter/Space to activate an element
+    --- When false, focus remains on the element after activation
+    dropFocusOnSelection = true,
+
+    -- Developer tools
+    developerTools = {
+      enabled = true,
+      showProperties = true,
+      highlightColor = { 1, 0.8, 0, 0.5 },
+    },
+
+    -- Focus indicator style
+    focusIndicator = {
+      color = { 0.2, 0.6, 1.0, 0.8 },
+      lineWidth = 2,
+      inset = -3,
+      borderRadius = 4,
+      animationDuration = 0.15,
+    },
+  },
+
+  -- State
+  _navigationStack = {},
+  _lastNavigationTime = 0,
+  _inspectMode = false,
+  _deps = nil,
+
+  -- Spatial index for directional navigation (performance optimization)
+  _spatialIndex = {
+    enabled = false,
+    cellSize = 100, -- Grid cell size in pixels
+    grid = {}, -- Grid storing element references
+    elementPositions = {}, -- Cache of element positions {element = {x, y, w, h}}
+    lastUpdateFrame = 0,
+  },
+}
+
+--- Initialize KeyboardNavigation module
+---@param deps table {Context, Element, ErrorHandler, utils, InputEvent}
+function KeyboardNavigation.init(deps)
+  -- Validate required dependencies
+  local required = { Context = true, Element = true, ErrorHandler = true, utils = true, InputEvent = true }
+  for depName, _ in pairs(required) do
+    if not deps[depName] then
+      error(string.format("KeyboardNavigation.init: Missing required dependency: %s", depName))
+    end
+  end
+
+  KeyboardNavigation._deps = deps
+  KeyboardNavigation._ErrorHandler = deps.ErrorHandler
+  KeyboardNavigation._InputEvent = deps.InputEvent
+  KeyboardNavigation._Context = deps.Context
+  KeyboardNavigation._Element = deps.Element
+  KeyboardNavigation._utils = deps.utils
+end
+
+--- Handle keyboard press for navigation
+---@param key string
+---@param scancode string
+---@param isrepeat boolean
+---@return boolean handled
+function KeyboardNavigation:handleKeyPress(key, scancode, isrepeat)
+  if not KeyboardNavigation._Context then
+    return false
+  end
+
+  -- Debug logging
+  if KeyboardNavigation.config.debugMode then
+    print(
+      string.format(
+        "[KeyboardNavigation] Key pressed: %s (scancode: %s, repeat: %s)",
+        key,
+        scancode,
+        tostring(isrepeat)
+      )
+    )
+    print(string.format("[KeyboardNavigation] Enabled: %s", tostring(KeyboardNavigation.config.enabled)))
+  end
+
+  local config = KeyboardNavigation.config
+  local keys = config.keys
+
+  -- Check for activation keys
+  for _, activateKey in ipairs(keys.activate) do
+    if key == activateKey then
+      return self:activateElement()
+    end
+  end
+
+  -- Check for dismiss key
+  if key == keys.dismiss then
+    return self:dismissElement()
+  end
+
+  -- Check for next/previous navigation
+  -- Tab with shift held = previous; Tab without shift = next
+  if key == keys.next then
+    if love.keyboard.isDown("lshift") or love.keyboard.isDown("rshift") then
+      return self:previousFocusable()
+    end
+    return self:nextFocusable()
+  end
+
+  if key == keys.previous then
+    return self:previousFocusable()
+  end
+
+  -- Check for directional navigation
+  if config.directionalNavigation then
+    if key == keys.up then
+      return self:navigateDirectional("up")
+    elseif key == keys.down then
+      return self:navigateDirectional("down")
+    elseif key == keys.left then
+      return self:navigateDirectional("left")
+    elseif key == keys.right then
+      return self:navigateDirectional("right")
+    end
+  end
+
+  return false
+end
+
+--- Find next focusable element in the focusable list
+---@param focusableList table<Element> List of focusable elements in tab order
+---@param current Element? Currently focused element
+---@return Element?
+function KeyboardNavigation:_findNextInList(focusableList, current)
+  local currentIndex = 0
+  if current then
+    for i, elem in ipairs(focusableList) do
+      if elem.id == current.id then
+        currentIndex = i
+        break
+      end
+    end
+  end
+
+  -- Search forward
+  if currentIndex < #focusableList then
+    return focusableList[currentIndex + 1]
+  end
+
+  -- Wrap around if enabled
+  if KeyboardNavigation.config.wrapAround and #focusableList > 0 then
+    return focusableList[1]
+  end
+
+  return nil
+end
+
+--- Get the focusable element list scoped to the navigation container
+---@return Element[]
+function KeyboardNavigation:_getScopedFocusableList()
+  local Context = KeyboardNavigation._Context
+  local container = Context.getNavigationContainer()
+  if container then
+    return container:getFocusableChildren()
+  end
+  return Context.getFocusableElements()
+end
+
+--- Navigate to next focusable element (Tab)
+---@return boolean success
+function KeyboardNavigation:nextFocusable()
+  local Context = KeyboardNavigation._Context
+
+  local current = Context.getFocused()
+  if KeyboardNavigation.config.debugMode then
+    print(
+      string.format("[KeyboardNavigation] Tab pressed - Current focus: %s", tostring(current and current.id or "nil"))
+    )
+  end
+
+  local focusableList = self:_getScopedFocusableList()
+  local nextElem = self:_findNextInList(focusableList, current)
+
+  if nextElem then
+    self:_focusElement(nextElem)
+    return true
+  end
+
+  return false
+end
+
+--- Find previous focusable element in the focusable list
+---@param focusableList table<Element> List of focusable elements in tab order
+---@param current Element? Currently focused element
+---@return Element?
+function KeyboardNavigation:_findPreviousInList(focusableList, current)
+  local currentIndex = #focusableList + 1
+  if current then
+    for i, elem in ipairs(focusableList) do
+      if elem.id == current.id then
+        currentIndex = i
+        break
+      end
+    end
+  end
+
+  -- Search backward
+  if currentIndex - 1 >= 1 then
+    return focusableList[currentIndex - 1]
+  end
+
+  -- Wrap around if enabled
+  if KeyboardNavigation.config.wrapAround and #focusableList > 0 then
+    return focusableList[#focusableList]
+  end
+
+  return nil
+end
+
+--- Navigate to previous focusable element (Shift+Tab)
+---@return boolean success
+function KeyboardNavigation:previousFocusable()
+  local Context = KeyboardNavigation._Context
+
+  local current = Context.getFocused()
+
+  local focusableList = self:_getScopedFocusableList()
+  local prevElem = self:_findPreviousInList(focusableList, current)
+
+  if prevElem then
+    self:_focusElement(prevElem)
+    return true
+  end
+
+  return false
+end
+
+--- Navigate using arrow keys
+---@param direction "up"|"down"|"left"|"right"
+---@return boolean success
+function KeyboardNavigation:navigateDirectional(direction)
+  local Context = KeyboardNavigation._Context
+  local current = Context.getFocused()
+
+  if not current then
+    return false
+  end
+
+  local nextElem = KeyboardNavigation:_findDirectionalNeighbor(current, direction)
+
+  if nextElem then
+    self:_focusElement(nextElem)
+    return true
+  end
+
+  return false
+end
+
+--- Find closest focusable element in the given direction
+---@param current Element
+---@param direction "up"|"down"|"left"|"right"
+---@return Element?
+function KeyboardNavigation:_findDirectionalNeighbor(current, direction)
+  -- Try spatial index first if enabled
+  if KeyboardNavigation._spatialIndex.enabled then
+    local spatialResult = self:_findDirectionalNeighborSpatial(current, direction)
+    if spatialResult then
+      return spatialResult
+    end
+  end
+
+  -- Collect all focusable elements visible this frame
+  local Context = KeyboardNavigation._Context
+  local focusable = {}
+
+  local function collectFocusable(elem)
+    if elem:isFocusable() and elem ~= current then
+      table.insert(focusable, elem)
+    end
+    for _, child in ipairs(elem.children) do
+      collectFocusable(child)
+    end
+  end
+
+  -- Mode-agnostic: collect from Context's focusable list
+  local allFocusable = Context.getFocusableElements()
+  for _, elem in ipairs(allFocusable) do
+    if elem ~= current then
+      table.insert(focusable, elem)
+    end
+  end
+
+  if #focusable == 0 then
+    return nil
+  end
+
+  local currentRect = {
+    x = current.x,
+    y = current.y,
+    width = current.width or 0,
+    height = current.height or 0,
+  }
+
+  local closest = nil
+  local closestDistance = math.huge
+
+  for _, elem in ipairs(focusable) do
+    local elemRect = {
+      x = elem.x,
+      y = elem.y,
+      width = elem.width or 0,
+      height = elem.height or 0,
+    }
+
+    local distance, isInDirection = self:_calculateDirectionalDistance(currentRect, elemRect, direction)
+
+    if isInDirection and distance < closestDistance then
+      closest = elem
+      closestDistance = distance
+    end
+  end
+
+  -- If no element found in exact direction, try with looser criteria
+  if not closest then
+    closest = self:_findClosestInDirection(current, focusable, direction)
+  end
+
+  return closest
+end
+
+--- Calculate distance and direction between elements
+---@param from table {x, y, width, height}
+---@param to table {x, y, width, height}
+---@param direction string
+---@return number distance, boolean isInDirection
+function KeyboardNavigation:_calculateDirectionalDistance(from, to, direction)
+  -- Calculate bounding box edges
+  local fromLeft = from.x
+  local fromRight = from.x + from.width
+  local fromTop = from.y
+  local fromBottom = from.y + from.height
+
+  local toLeft = to.x
+  local toRight = to.x + to.width
+  local toTop = to.y
+  local toBottom = to.y + to.height
+
+  local distance = math.huge
+  local isInDirection = false
+
+  if direction == "up" then
+    if toBottom < fromTop then
+      isInDirection = true
+      distance = fromTop - toBottom
+    end
+  elseif direction == "down" then
+    if toTop > fromBottom then
+      isInDirection = true
+      distance = toTop - fromBottom
+    end
+  elseif direction == "left" then
+    if toRight < fromLeft then
+      isInDirection = true
+      distance = fromLeft - toRight
+    end
+  elseif direction == "right" then
+    if toLeft > fromRight then
+      isInDirection = true
+      distance = toLeft - fromRight
+    end
+  end
+
+  return distance, isInDirection
+end
+
+--- Find closest element in direction using center-to-center distance
+---@param current Element
+---@param focusable Element[]
+---@param direction string
+---@return Element?
+function KeyboardNavigation:_findClosestInDirection(current, focusable, direction)
+  local currentCenterX = current.x + (current.width or 0) / 2
+  local currentCenterY = current.y + (current.height or 0) / 2
+
+  local closest = nil
+  local closestDistance = math.huge
+
+  for _, elem in ipairs(focusable) do
+    if elem ~= current then
+      local elemCenterX = elem.x + (elem.width or 0) / 2
+      local elemCenterY = elem.y + (elem.height or 0) / 2
+
+      local dx = elemCenterX - currentCenterX
+      local dy = elemCenterY - currentCenterY
+
+      -- Check if element is generally in the right direction
+      local isInDirection = false
+
+      if direction == "up" and dy < 0 then
+        isInDirection = true
+      elseif direction == "down" and dy > 0 then
+        isInDirection = true
+      elseif direction == "left" and dx < 0 then
+        isInDirection = true
+      elseif direction == "right" and dx > 0 then
+        isInDirection = true
+      end
+
+      if isInDirection then
+        local distance = math.sqrt(dx * dx + dy * dy)
+        if distance < closestDistance then
+          closest = elem
+          closestDistance = distance
+        end
+      end
+    end
+  end
+
+  return closest
+end
+
+--- Focus an element
+---@param element Element
+function KeyboardNavigation:_focusElement(element)
+  local Context = KeyboardNavigation._Context
+
+  if element and element:isFocusable() then
+    if KeyboardNavigation.config.debugMode then
+      print(
+        string.format(
+          "[KeyboardNavigation] Focusing element: %s (id: %s)",
+          element.themeComponent or "unknown",
+          tostring(element.id)
+        )
+      )
+    end
+    Context.setFocused(element)
+
+    -- Update focus indicator
+    if KeyboardNavigation.FocusIndicator then
+      KeyboardNavigation.FocusIndicator.setFocused(element)
+    end
+
+    -- Call onFocus callback if it exists
+    if element.onFocus then
+      local success, err = pcall(function()
+        if element.onFocusDeferred then
+          table.insert(Context._deferredCallbacks or {}, function()
+            element:onFocus(element)
+          end)
+        else
+          element:onFocus(element)
+        end
+      end)
+
+      if not success then
+        KeyboardNavigation._ErrorHandler:warn("KeyboardNavigation", "NAV_001", {
+          elementId = element.id or "unknown",
+          error = tostring(err),
+        })
+      end
+    end
+  end
+end
+
+---@param element Element
+---@return boolean
+function KeyboardNavigation:_shouldDropFocusOnSelection(element)
+  if element and element.dropFocusOnSelection ~= nil then
+    return element.dropFocusOnSelection == true
+  end
+
+  return KeyboardNavigation.config.dropFocusOnSelection == true
+end
+
+--- Activate currently focused element
+---@return boolean success
+function KeyboardNavigation:activateElement()
+  local Context = KeyboardNavigation._Context
+  local focused = Context.getFocused()
+
+  if not focused then
+    return false
+  end
+
+  if focused.disabled then
+    return false
+  end
+
+  -- Fire press and release events
+  if focused.onEvent then
+    local modifiers = KeyboardNavigation._utils.getModifiers()
+    local pressEvent = KeyboardNavigation._InputEvent.new({
+      type = "press",
+      button = 1,
+      x = focused.x,
+      y = focused.y,
+      modifiers = modifiers,
+      clickCount = 1,
+    })
+
+    local releaseEvent = KeyboardNavigation._InputEvent.new({
+      type = "release",
+      button = 1,
+      x = focused.x,
+      y = focused.y,
+      modifiers = modifiers,
+      clickCount = 1,
+    })
+
+    local success, err = pcall(function()
+      focused.onEvent(focused, pressEvent)
+      focused.onEvent(focused, releaseEvent)
+    end)
+
+    if not success then
+      KeyboardNavigation._ErrorHandler:warn("KeyboardNavigation", "NAV_002", {
+        elementId = focused.id or "unknown",
+        error = tostring(err),
+      })
+    end
+
+    -- Drop focus after selection based on per-element override or global config.
+    if KeyboardNavigation:_shouldDropFocusOnSelection(focused) then
+      Context.clearFocus()
+      if KeyboardNavigation.FocusIndicator then
+        KeyboardNavigation.FocusIndicator.setFocused(nil)
+      end
+    end
+
+    return true
+  end
+
+  return false
+end
+
+--- Dismiss currently focused element
+---@return boolean success
+function KeyboardNavigation:dismissElement()
+  local Context = KeyboardNavigation._Context
+  local focused = Context.getFocused()
+
+  if not focused then
+    return false
+  end
+
+  -- Check if element has a dismiss handler
+  if focused.onDismiss then
+    local success, err = pcall(function()
+      if focused.onDismissDeferred then
+        table.insert(Context._deferredCallbacks or {}, function()
+          focused:onDismiss(focused)
+        end)
+      else
+        focused:onDismiss(focused)
+      end
+    end)
+
+    if not success then
+      KeyboardNavigation._ErrorHandler:warn("KeyboardNavigation", "NAV_003", {
+        elementId = focused.id or "unknown",
+        error = tostring(err),
+      })
+    end
+
+    return true -- Handler took care of dismissal
+  end
+
+  -- Default behavior: blur the element (only if no onDismiss handler)
+  Context.clearFocus()
+  return true
+end
+
+--- Update keyboard navigation (for animations, etc.)
+---@param dt number
+function KeyboardNavigation:update(dt)
+  -- Update focus indicator if it exists
+  if KeyboardNavigation.FocusIndicator then
+    KeyboardNavigation.FocusIndicator:update(dt)
+  end
+end
+
+--- Push current focus onto stack (for modals/dialogs)
+--- Saves current focus and sets new focus to the given element
+---@param element Element? The element to focus (e.g., modal dialog)
+function KeyboardNavigation:pushFocus(element)
+  local Context = KeyboardNavigation._Context
+
+  table.insert(KeyboardNavigation._navigationStack, Context.getFocused())
+  Context.pushFocusStack(element)
+end
+
+--- Pop focus from stack (return from modal)
+--- Restores previously focused element from the stack
+---@return Element? The previously focused element, or nil if stack was empty
+function KeyboardNavigation:popFocus()
+  local Context = KeyboardNavigation._Context
+
+  local previous = Context.popFocusStack()
+  if #KeyboardNavigation._navigationStack > 0 then
+    previous = table.remove(KeyboardNavigation._navigationStack)
+  end
+
+  return previous
+end
+
+-- ====================
+-- Spatial Index (Performance Optimization)
+-- ====================
+
+--- Enable spatial index for faster directional navigation
+---@param enabled boolean
+function KeyboardNavigation.enableSpatialIndex(enabled)
+  KeyboardNavigation._spatialIndex.enabled = enabled
+  if not enabled then
+    KeyboardNavigation:_clearSpatialIndex()
+  end
+end
+
+--- Clear spatial index
+function KeyboardNavigation:_clearSpatialIndex()
+  KeyboardNavigation._spatialIndex.grid = {}
+  KeyboardNavigation._spatialIndex.elementPositions = {}
+end
+
+--- Find directional neighbor using spatial index
+---@param current Element
+---@param direction "up"|"down"|"left"|"right"
+---@return Element?
+function KeyboardNavigation:_findDirectionalNeighborSpatial(current, direction)
+  local index = KeyboardNavigation._spatialIndex
+  local cellSize = index.cellSize
+
+  -- Get current element's grid position
+  local currentPos = index.elementPositions[current]
+  if not currentPos then
+    return nil
+  end
+
+  local centerX = currentPos.x + currentPos.w / 2
+  local centerY = currentPos.y + currentPos.h / 2
+  local currentCellX = math.floor(centerX / cellSize)
+  local currentCellY = math.floor(centerY / cellSize)
+
+  -- Search in direction, expanding outward
+  local maxSearchRadius = 20 -- Maximum cells to search
+  local visited = {}
+
+  for radius = 1, maxSearchRadius do
+    local candidates = {}
+
+    -- Get cells in the search ring
+    if direction == "up" then
+      table.insert(candidates, { currentCellX, currentCellY - radius })
+      if radius > 1 then
+        table.insert(candidates, { currentCellX - 1, currentCellY - radius })
+        table.insert(candidates, { currentCellX + 1, currentCellY - radius })
+      end
+    elseif direction == "down" then
+      table.insert(candidates, { currentCellX, currentCellY + radius })
+      if radius > 1 then
+        table.insert(candidates, { currentCellX - 1, currentCellY + radius })
+        table.insert(candidates, { currentCellX + 1, currentCellY + radius })
+      end
+    elseif direction == "left" then
+      table.insert(candidates, { currentCellX - radius, currentCellY })
+      if radius > 1 then
+        table.insert(candidates, { currentCellX - radius, currentCellY - 1 })
+        table.insert(candidates, { currentCellX - radius, currentCellY + 1 })
+      end
+    elseif direction == "right" then
+      table.insert(candidates, { currentCellX + radius, currentCellY })
+      if radius > 1 then
+        table.insert(candidates, { currentCellX + radius, currentCellY - 1 })
+        table.insert(candidates, { currentCellX + radius, currentCellY + 1 })
+      end
+    end
+
+    -- Check each candidate cell
+    for _, cell in ipairs(candidates) do
+      local cellKey = string.format("%d,%d", cell[1], cell[2])
+      local cellElements = index.grid[cellKey]
+
+      if cellElements then
+        for _, elem in ipairs(cellElements) do
+          if elem ~= current and not visited[elem] then
+            visited[elem] = true
+            local elemPos = index.elementPositions[elem]
+            if elemPos then
+              local elemCenterX = elemPos.x + elemPos.w / 2
+              local elemCenterY = elemPos.y + elemPos.h / 2
+
+              -- Check if element is in the correct direction
+              local isInDirection = false
+              if direction == "up" and elemCenterY < centerY then
+                isInDirection = true
+              elseif direction == "down" and elemCenterY > centerY then
+                isInDirection = true
+              elseif direction == "left" and elemCenterX < centerX then
+                isInDirection = true
+              elseif direction == "right" and elemCenterX > centerX then
+                isInDirection = true
+              end
+
+              if isInDirection then
+                return elem
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+
+  return nil
+end
+
+return KeyboardNavigation

libs/flexlove/modules/MemoryScanner.lua

@@ -0,0 +1,697 @@
+---@class MemoryScanner
+---@field _StateManager table
+---@field _Context table
+---@field _ImageCache table
+---@field _ErrorHandler table
+local MemoryScanner = {}
+
+---Initialize MemoryScanner with dependencies
+---@param deps {StateManager: table, Context: table, ImageCache: table, ErrorHandler: table}
+function MemoryScanner.init(deps)
+  MemoryScanner._StateManager = deps.StateManager
+  MemoryScanner._Context = deps.Context
+  MemoryScanner._ImageCache = deps.ImageCache
+  MemoryScanner._ErrorHandler = deps.ErrorHandler
+end
+
+---Count items in a table
+---@param tbl table
+---@return number
+local function countTable(tbl)
+  local count = 0
+  for _ in pairs(tbl) do
+    count = count + 1
+  end
+  return count
+end
+
+---Calculate memory size estimate for a table (recursive)
+---@param tbl table
+---@param visited table? Tracking table to prevent circular references
+---@param depth number? Current recursion depth
+---@return number bytes Estimated memory usage in bytes
+local function estimateTableSize(tbl, visited, depth)
+  if type(tbl) ~= "table" then
+    return 0
+  end
+
+  visited = visited or {}
+  depth = depth or 0
+
+  -- Limit recursion depth to prevent stack overflow
+  if depth > 10 then
+    return 0
+  end
+
+  -- Check for circular references
+  if visited[tbl] then
+    return 0
+  end
+  visited[tbl] = true
+
+  local size = 40 -- Base table overhead (approximate)
+
+  for k, v in pairs(tbl) do
+    -- Key size
+    if type(k) == "string" then
+      size = size + #k + 24 -- String overhead
+    elseif type(k) == "number" then
+      size = size + 8
+    else
+      size = size + 8 -- Reference
+    end
+
+    -- Value size
+    if type(v) == "string" then
+      size = size + #v + 24
+    elseif type(v) == "number" then
+      size = size + 8
+    elseif type(v) == "boolean" then
+      size = size + 4
+    elseif type(v) == "table" then
+      size = size + estimateTableSize(v, visited, depth + 1)
+    elseif type(v) == "function" then
+      size = size + 16 -- Function reference
+    else
+      size = size + 8 -- Other references
+    end
+  end
+
+  return size
+end
+
+---Scan StateManager for memory issues
+---@return table report Detailed report of StateManager memory usage
+function MemoryScanner.scanStateManager()
+  local report = {
+    stateCount = 0,
+    stateStoreSize = 0,
+    metadataSize = 0,
+    callSiteCounterSize = 0,
+    orphanedStates = {},
+    staleStates = {},
+    largeStates = {},
+    issues = {},
+  }
+
+  if not MemoryScanner._StateManager then
+    table.insert(report.issues, {
+      severity = "error",
+      message = "StateManager not initialized",
+    })
+    return report
+  end
+
+  local internal = MemoryScanner._StateManager._getInternalState()
+  local stateStore = internal.stateStore
+  local stateMetadata = internal.stateMetadata
+  local callSiteCounters = internal.callSiteCounters
+  local currentFrame = MemoryScanner._StateManager.getFrameNumber()
+
+  -- Count states
+  report.stateCount = countTable(stateStore)
+
+  -- Estimate sizes
+  report.stateStoreSize = estimateTableSize(stateStore)
+  report.metadataSize = estimateTableSize(stateMetadata)
+  report.callSiteCounterSize = estimateTableSize(callSiteCounters)
+
+  -- Check for orphaned states (metadata without state)
+  for id, _ in pairs(stateMetadata) do
+    if not stateStore[id] then
+      table.insert(report.orphanedStates, id)
+    end
+  end
+
+  -- Check for stale states (not accessed in many frames)
+  local staleThreshold = 120 -- 2 seconds at 60fps
+  for id, meta in pairs(stateMetadata) do
+    local framesSinceAccess = currentFrame - meta.lastFrame
+    if framesSinceAccess > staleThreshold then
+      table.insert(report.staleStates, {
+        id = id,
+        framesSinceAccess = framesSinceAccess,
+        createdFrame = meta.createdFrame,
+        accessCount = meta.accessCount,
+      })
+    end
+  end
+
+  -- Check for large states (may indicate memory bloat)
+  for id, state in pairs(stateStore) do
+    local stateSize = estimateTableSize(state)
+    if stateSize > 1024 then -- More than 1KB
+      table.insert(report.largeStates, {
+        id = id,
+        size = stateSize,
+        keyCount = countTable(state),
+      })
+    end
+  end
+
+  -- Check callSiteCounters (should be near 0 after frame cleanup)
+  local callSiteCount = countTable(callSiteCounters)
+  if callSiteCount > 100 then
+    table.insert(report.issues, {
+      severity = "warning",
+      message = string.format("callSiteCounters has %d entries (expected near 0)", callSiteCount),
+      suggestion = "incrementFrame() may not be called properly, or counters aren't being reset",
+    })
+  end
+
+  -- Check for excessive state count
+  if report.stateCount > 500 then
+    table.insert(report.issues, {
+      severity = "warning",
+      message = string.format("High state count: %d states", report.stateCount),
+      suggestion = "Consider reducing element count or implementing more aggressive cleanup",
+    })
+  end
+
+  -- Check for orphaned states
+  if #report.orphanedStates > 0 then
+    table.insert(report.issues, {
+      severity = "error",
+      message = string.format("Found %d orphaned states (metadata without state)", #report.orphanedStates),
+      suggestion = "This indicates a bug in state management - metadata should be cleaned up with state",
+    })
+  end
+
+  -- Check for stale states
+  if #report.staleStates > 10 then
+    table.insert(report.issues, {
+      severity = "warning",
+      message = string.format("Found %d stale states (not accessed in 2+ seconds)", #report.staleStates),
+      suggestion = "Cleanup may not be aggressive enough - consider reducing stateRetentionFrames",
+    })
+  end
+
+  return report
+end
+
+---Scan Context for memory issues
+---@return table report Detailed report of Context memory usage
+function MemoryScanner.scanContext()
+  local report = {
+    topElementCount = 0,
+    zIndexElementCount = 0,
+    frameElementCount = 0,
+    issues = {},
+  }
+
+  if not MemoryScanner._Context then
+    table.insert(report.issues, {
+      severity = "error",
+      message = "Context not initialized",
+    })
+    return report
+  end
+
+  -- Count elements
+  report.topElementCount = #MemoryScanner._Context.topElements
+  report.zIndexElementCount = #MemoryScanner._Context._zIndexOrderedElements
+  report.frameElementCount = #MemoryScanner._Context._currentFrameElements
+
+  -- Check for stale z-index elements (should be cleared each frame)
+  if MemoryScanner._Context.isImmediateMode() then
+    -- In immediate mode, _zIndexOrderedElements should be cleared at frame start
+    -- If it has elements outside of frame rendering, that's a leak
+    if not MemoryScanner._Context._frameStarted and report.zIndexElementCount > 0 then
+      table.insert(report.issues, {
+        severity = "warning",
+        message = string.format("Z-index array has %d elements outside of frame", report.zIndexElementCount),
+        suggestion = "clearFrameElements() may not be called properly in beginFrame()",
+      })
+    end
+  end
+
+  -- Check for excessive element count
+  if report.topElementCount > 100 then
+    table.insert(report.issues, {
+      severity = "info",
+      message = string.format("High top-level element count: %d", report.topElementCount),
+      suggestion = "Consider consolidating elements or using fewer top-level containers",
+    })
+  end
+
+  return report
+end
+
+---Scan ImageCache for memory issues
+---@return table report Detailed report of ImageCache memory usage
+function MemoryScanner.scanImageCache()
+  local report = {
+    imageCount = 0,
+    estimatedMemory = 0,
+    issues = {},
+  }
+
+  if not MemoryScanner._ImageCache then
+    table.insert(report.issues, {
+      severity = "error",
+      message = "ImageCache not initialized",
+    })
+    return report
+  end
+
+  local stats = MemoryScanner._ImageCache.getStats()
+  report.imageCount = stats.count
+  report.estimatedMemory = stats.memoryEstimate
+
+  -- Check for excessive memory usage (>100MB)
+  if report.estimatedMemory > 100 * 1024 * 1024 then
+    table.insert(report.issues, {
+      severity = "warning",
+      message = string.format("ImageCache using ~%.2f MB", report.estimatedMemory / 1024 / 1024),
+      suggestion = "Consider implementing cache eviction or clearing unused images",
+    })
+  end
+
+  -- Check for excessive image count
+  if report.imageCount > 50 then
+    table.insert(report.issues, {
+      severity = "info",
+      message = string.format("ImageCache has %d images", report.imageCount),
+      suggestion = "Review if all cached images are necessary",
+    })
+  end
+
+  return report
+end
+
+---Check if a circular reference is intentional (parent-child, module, or metatable)
+---@param path string The current path where circular ref was detected
+---@param originalPath string The original path where the table was first seen
+---@return boolean True if this is an intentional circular reference
+local function isIntentionalCircularReference(path, originalPath)
+  -- Pattern 1: child.parent points back to parent
+  -- Example: "topElements.1.children.1.parent" -> "topElements.1"
+  if path:match("%.parent$") then
+    local parentPath = path:match("^(.+)%.children%.[^.]+%.parent$")
+    if parentPath == originalPath then
+      return true
+    end
+  end
+
+  -- Pattern 2: parent.children[n] points to child, child points back somewhere in parent tree
+  -- Example: "topElements.1" -> "topElements.1.children.1.parent"
+  if originalPath:match("%.parent$") then
+    local childParentPath = originalPath:match("^(.+)%.children%.[^.]+%.parent$")
+    if childParentPath == path then
+      return true
+    end
+  end
+
+  -- Pattern 3: Check for nested parent-child cycles
+  -- child.children[n].parent -> child
+  local segments = {}
+  for segment in path:gmatch("[^.]+") do
+    table.insert(segments, segment)
+  end
+
+  -- Look for .children.N.parent pattern
+  for i = 1, #segments - 2 do
+    if segments[i] == "children" and segments[i + 2] == "parent" then
+      -- Reconstruct path without the .children.N.parent suffix
+      local reconstructedPath = table.concat(segments, ".", 1, i - 1)
+      if reconstructedPath == originalPath then
+        return true
+      end
+    end
+  end
+
+  -- Pattern 4: Metatable __index self-references (modules)
+  -- Example: "element._renderer._Theme.__index" -> "element._renderer._Theme"
+  if path:match("%.__index$") then
+    local basePath = path:match("^(.+)%.__index$")
+    if basePath == originalPath then
+      return true
+    end
+  end
+
+  -- Pattern 5: Shared module references (elements sharing same module instances)
+  -- Example: Multiple elements referencing _utils, _Theme, _Blur, etc.
+  -- These start with _ and are typically modules
+  local pathModuleName = path:match("%.(_[%w]+)%.")
+  local originalModuleName = originalPath:match("%.(_[%w]+)%.")
+
+  if pathModuleName and originalModuleName then
+    -- If both paths reference the same internal module (starting with _), it's intentional
+    if pathModuleName == originalModuleName then
+      return true
+    end
+  end
+
+  -- Pattern 6: Shared Color/Transform objects between elements
+  -- These are value objects that can be safely shared
+  if path:match("Color") and originalPath:match("Color") then
+    return true
+  end
+  if path:match("Transform") and originalPath:match("Transform") then
+    return true
+  end
+
+  -- Pattern 7: LayoutEngine holding reference to its element
+  -- Example: "element._layoutEngine.element" -> "element"
+  if path:match("%._layoutEngine%.element$") then
+    local elementPath = path:match("^(.+)%._layoutEngine%.element$")
+    if elementPath == originalPath then
+      return true
+    end
+  end
+
+  -- Pattern 8: Renderer holding references to element properties
+  -- Example: "element._renderer.cornerRadius" -> "element.cornerRadius"
+  if path:match("%._renderer%.") then
+    local rendererBasePath = path:match("^(.+)%._renderer%.")
+    local originalBasePath = originalPath:match("^(.+)%.")
+    if rendererBasePath == originalBasePath then
+      return true
+    end
+  end
+
+  -- Pattern 9: Context reference from layout engine (shared singleton)
+  -- Example: "element._layoutEngine._Context.topElements" -> "topElements"
+  if path:match("%._layoutEngine%._Context%.") and originalPath == "topElements" then
+    return true
+  end
+
+  return false
+end
+
+---Detect circular references in a table
+---@param tbl table Table to check
+---@param path string? Current path (for reporting)
+---@param visited table? Tracking table
+---@return table[] circularRefs Array of circular reference paths
+---@return table[] intentionalRefs Array of intentional parent-child refs
+local function detectCircularReferences(tbl, path, visited)
+  if type(tbl) ~= "table" then
+    return {}, {}
+  end
+
+  path = path or "root"
+  visited = visited or {}
+  local circularRefs = {}
+  local intentionalRefs = {}
+
+  -- Check if we've seen this table before
+  if visited[tbl] then
+    local ref = {
+      path = path,
+      originalPath = visited[tbl],
+    }
+
+    -- Determine if this is an intentional circular reference
+    if isIntentionalCircularReference(path, visited[tbl]) then
+      table.insert(intentionalRefs, ref)
+    else
+      table.insert(circularRefs, ref)
+    end
+
+    return circularRefs, intentionalRefs
+  end
+
+  -- Mark as visited
+  visited[tbl] = path
+
+  -- Recursively check children
+  for k, v in pairs(tbl) do
+    if type(v) == "table" then
+      local childPath = path .. "." .. tostring(k)
+      local childRefs, childIntentionalRefs = detectCircularReferences(v, childPath, visited)
+      for _, ref in ipairs(childRefs) do
+        table.insert(circularRefs, ref)
+      end
+      for _, ref in ipairs(childIntentionalRefs) do
+        table.insert(intentionalRefs, ref)
+      end
+    end
+  end
+
+  return circularRefs, intentionalRefs
+end
+
+---Scan for circular references in immediate mode
+---@return table report Detailed report of circular references
+function MemoryScanner.scanCircularReferences()
+  local report = {
+    stateStoreCircularRefs = {},
+    stateStoreIntentionalRefs = {},
+    contextCircularRefs = {},
+    contextIntentionalRefs = {},
+    issues = {},
+  }
+
+  if MemoryScanner._StateManager then
+    local internal = MemoryScanner._StateManager._getInternalState()
+    report.stateStoreCircularRefs, report.stateStoreIntentionalRefs =
+      detectCircularReferences(internal.stateStore, "stateStore")
+  end
+
+  if MemoryScanner._Context then
+    report.contextCircularRefs, report.contextIntentionalRefs =
+      detectCircularReferences(MemoryScanner._Context.topElements, "topElements")
+  end
+
+  -- Report issues only for cross-module circular references
+  if #report.stateStoreCircularRefs > 0 then
+    table.insert(report.issues, {
+      severity = "info",
+      message = string.format(
+        "Found %d cross-module circular references in StateManager",
+        #report.stateStoreCircularRefs
+      ),
+      suggestion = "These are typically architectural dependencies between modules, not memory leaks",
+    })
+  end
+
+  if #report.contextCircularRefs > 0 then
+    table.insert(report.issues, {
+      severity = "info",
+      message = string.format("Found %d cross-module circular references in Context", #report.contextCircularRefs),
+      suggestion = "These are typically architectural dependencies (e.g., layout engine ↔ renderer), not memory leaks",
+    })
+  end
+
+  return report
+end
+
+---Run comprehensive memory scan
+---@return table report Complete memory analysis report
+function MemoryScanner.scan()
+  local startMemory = collectgarbage("count")
+
+  local report = {
+    timestamp = os.time(),
+    startMemory = startMemory / 1024, -- MB
+    stateManager = MemoryScanner.scanStateManager(),
+    context = MemoryScanner.scanContext(),
+    imageCache = MemoryScanner.scanImageCache(),
+    circularRefs = MemoryScanner.scanCircularReferences(),
+    summary = {
+      totalIssues = 0,
+      criticalIssues = 0,
+      warnings = 0,
+      info = 0,
+    },
+  }
+
+  -- Count issues by severity
+  local function countIssues(subReport)
+    for _, issue in ipairs(subReport.issues or {}) do
+      report.summary.totalIssues = report.summary.totalIssues + 1
+      if issue.severity == "error" then
+        report.summary.criticalIssues = report.summary.criticalIssues + 1
+      elseif issue.severity == "warning" then
+        report.summary.warnings = report.summary.warnings + 1
+      elseif issue.severity == "info" then
+        report.summary.info = report.summary.info + 1
+      end
+    end
+  end
+
+  countIssues(report.stateManager)
+  countIssues(report.context)
+  countIssues(report.imageCache)
+  countIssues(report.circularRefs)
+
+  -- Force GC and measure freed memory
+  local beforeGC = collectgarbage("count")
+  collectgarbage("collect")
+  collectgarbage("collect")
+  local afterGC = collectgarbage("count")
+
+  report.gcAnalysis = {
+    beforeGC = beforeGC / 1024, -- MB
+    afterGC = afterGC / 1024, -- MB
+    freed = (beforeGC - afterGC) / 1024, -- MB
+    freedPercent = ((beforeGC - afterGC) / beforeGC) * 100,
+  }
+
+  -- Analyze GC effectiveness
+  if report.gcAnalysis.freedPercent < 5 then
+    table.insert(report.stateManager.issues, {
+      severity = "info",
+      message = string.format("GC freed only %.1f%% of memory", report.gcAnalysis.freedPercent),
+      suggestion = "Most memory is still referenced - this is normal if UI is active",
+    })
+  elseif report.gcAnalysis.freedPercent > 30 then
+    table.insert(report.stateManager.issues, {
+      severity = "warning",
+      message = string.format("GC freed %.1f%% of memory", report.gcAnalysis.freedPercent),
+      suggestion = "Significant memory was unreferenced - may indicate cleanup issues",
+    })
+  end
+
+  return report
+end
+
+---Format report as human-readable string
+---@param report table Memory scan report
+---@return string formatted Formatted report
+function MemoryScanner.formatReport(report)
+  local lines = {}
+
+  table.insert(lines, "=== FlexLöve Memory Scanner Report ===")
+  table.insert(lines, string.format("Timestamp: %s", os.date("%Y-%m-%d %H:%M:%S", report.timestamp)))
+  table.insert(lines, string.format("Memory: %.2f MB", report.startMemory))
+  table.insert(lines, "")
+
+  -- Summary
+  table.insert(lines, "--- Summary ---")
+  table.insert(lines, string.format("Total Issues: %d", report.summary.totalIssues))
+  table.insert(lines, string.format("  Critical: %d", report.summary.criticalIssues))
+  table.insert(lines, string.format("  Warnings: %d", report.summary.warnings))
+  table.insert(lines, string.format("  Info: %d", report.summary.info))
+  table.insert(lines, "")
+
+  -- StateManager
+  table.insert(lines, "--- StateManager ---")
+  table.insert(lines, string.format("State Count: %d", report.stateManager.stateCount))
+  table.insert(lines, string.format("State Store Size: %.2f KB", report.stateManager.stateStoreSize / 1024))
+  table.insert(lines, string.format("Metadata Size: %.2f KB", report.stateManager.metadataSize / 1024))
+  table.insert(lines, string.format("CallSite Counters: %.2f KB", report.stateManager.callSiteCounterSize / 1024))
+  table.insert(lines, string.format("Orphaned States: %d", #report.stateManager.orphanedStates))
+  table.insert(lines, string.format("Stale States: %d", #report.stateManager.staleStates))
+  table.insert(lines, string.format("Large States: %d", #report.stateManager.largeStates))
+
+  if #report.stateManager.issues > 0 then
+    table.insert(lines, "Issues:")
+    for _, issue in ipairs(report.stateManager.issues) do
+      table.insert(lines, string.format("  [%s] %s", string.upper(issue.severity), issue.message))
+      if issue.suggestion then
+        table.insert(lines, string.format("    → %s", issue.suggestion))
+      end
+    end
+  end
+  table.insert(lines, "")
+
+  -- Context
+  table.insert(lines, "--- Context ---")
+  table.insert(lines, string.format("Top Elements: %d", report.context.topElementCount))
+  table.insert(lines, string.format("Z-Index Elements: %d", report.context.zIndexElementCount))
+  table.insert(lines, string.format("Frame Elements: %d", report.context.frameElementCount))
+
+  if #report.context.issues > 0 then
+    table.insert(lines, "Issues:")
+    for _, issue in ipairs(report.context.issues) do
+      table.insert(lines, string.format("  [%s] %s", string.upper(issue.severity), issue.message))
+      if issue.suggestion then
+        table.insert(lines, string.format("    → %s", issue.suggestion))
+      end
+    end
+  end
+  table.insert(lines, "")
+
+  -- ImageCache
+  table.insert(lines, "--- ImageCache ---")
+  table.insert(lines, string.format("Image Count: %d", report.imageCache.imageCount))
+  table.insert(lines, string.format("Estimated Memory: %.2f MB", report.imageCache.estimatedMemory / 1024 / 1024))
+
+  if #report.imageCache.issues > 0 then
+    table.insert(lines, "Issues:")
+    for _, issue in ipairs(report.imageCache.issues) do
+      table.insert(lines, string.format("  [%s] %s", string.upper(issue.severity), issue.message))
+      if issue.suggestion then
+        table.insert(lines, string.format("    → %s", issue.suggestion))
+      end
+    end
+  end
+  table.insert(lines, "")
+
+  -- Circular References
+  table.insert(lines, "--- Circular References ---")
+  table.insert(lines, string.format("StateStore (Cross-module refs): %d", #report.circularRefs.stateStoreCircularRefs))
+  table.insert(
+    lines,
+    string.format(
+      "StateStore (Intentional - parent-child, modules, metatables): %d",
+      #report.circularRefs.stateStoreIntentionalRefs
+    )
+  )
+  table.insert(lines, string.format("Context (Cross-module refs): %d", #report.circularRefs.contextCircularRefs))
+  table.insert(
+    lines,
+    string.format(
+      "Context (Intentional - parent-child, modules, metatables): %d",
+      #report.circularRefs.contextIntentionalRefs
+    )
+  )
+
+  if #report.circularRefs.issues > 0 then
+    table.insert(lines, "Issues:")
+    for _, issue in ipairs(report.circularRefs.issues) do
+      table.insert(lines, string.format("  [%s] %s", string.upper(issue.severity), issue.message))
+      if issue.suggestion then
+        table.insert(lines, string.format("    → %s", issue.suggestion))
+      end
+    end
+  else
+    table.insert(lines, "  ✓ No unexpected circular references detected")
+  end
+  table.insert(lines, "  Note: Cross-module refs are typically architectural dependencies, not memory leaks")
+  table.insert(lines, "")
+
+  -- GC Analysis
+  table.insert(lines, "--- Garbage Collection Analysis ---")
+  table.insert(lines, string.format("Before GC: %.2f MB", report.gcAnalysis.beforeGC))
+  table.insert(lines, string.format("After GC: %.2f MB", report.gcAnalysis.afterGC))
+  table.insert(lines, string.format("Freed: %.2f MB (%.1f%%)", report.gcAnalysis.freed, report.gcAnalysis.freedPercent))
+  table.insert(lines, "")
+
+  table.insert(lines, "=== End Report ===")
+
+  return table.concat(lines, "\n")
+end
+
+---Save report to file
+---@param report table Memory scan report
+---@param filename string? Output filename (default: memory_report.txt)
+function MemoryScanner.saveReport(report, filename)
+  filename = filename or "memory_report.txt"
+  local formatted = MemoryScanner.formatReport(report)
+
+  local file = io.open(filename, "w")
+  if file then
+    file:write(formatted)
+    file:close()
+    if MemoryScanner._ErrorHandler then
+      MemoryScanner._ErrorHandler:warn("MemoryScanner", "RES_004", {
+        resourceType = "report",
+        path = filename,
+        status = "saved",
+      })
+    end
+  else
+    if MemoryScanner._ErrorHandler then
+      MemoryScanner._ErrorHandler:warn("MemoryScanner", "RES_004", {
+        resourceType = "report",
+        path = filename,
+        status = "failed to save",
+      })
+    end
+  end
+end
+
+return MemoryScanner

libs/flexlove/modules/ModuleLoader.lua

@@ -0,0 +1,202 @@
+---@class ModuleLoader
+local ModuleLoader = {}
+
+-- Module registry to track loaded vs. stub modules
+ModuleLoader._registry = {}
+ModuleLoader._ErrorHandler = nil
+
+--- Initialize ModuleLoader with dependencies
+---@param deps table
+function ModuleLoader.init(deps)
+  ModuleLoader._ErrorHandler = deps.ErrorHandler
+end
+
+--- Create a null-object stub for a missing optional module
+--- Provides safe defaults that won't cause runtime errors
+---@param moduleName string
+---@return table
+local function createNullObject(moduleName)
+  local stub = {
+    _isStub = true,
+    _moduleName = moduleName,
+  }
+
+  -- Common method stubs that return safe defaults
+  local metatable = {
+    __index = function(_, key)
+      -- Common initialization method
+      if key == "init" then
+        return function()
+          return stub
+        end
+      end
+
+      -- Common constructor method
+      if key == "new" then
+        return function()
+          return stub
+        end
+      end
+
+      -- Common draw method
+      if key == "draw" then
+        return function() end
+      end
+
+      -- Common update method
+      if key == "update" then
+        return function() end
+      end
+
+      -- Common render method
+      if key == "render" then
+        return function() end
+      end
+
+      -- Common cleanup method
+      if key == "destroy" then
+        return function() end
+      end
+
+      -- Common cleanup method
+      if key == "cleanup" then
+        return function() end
+      end
+
+      -- Common clear method
+      if key == "clear" then
+        return function() end
+      end
+
+      -- Common reset method
+      if key == "reset" then
+        return function() end
+      end
+
+      -- Common get method
+      if key == "get" then
+        return function()
+          return nil
+        end
+      end
+
+      -- Common set method
+      if key == "set" then
+        return function() end
+      end
+
+      -- Common load method
+      if key == "load" then
+        return function()
+          return stub
+        end
+      end
+
+      -- Common cache-related methods
+      if key == "cache" or key == "getCache" or key == "clearCache" then
+        return function()
+          return {}
+        end
+      end
+
+      -- For any unknown method, return a no-op function that accepts any arguments
+      -- This allows safe method calls on stub objects (e.g., Performance:startFrame())
+      return function()
+        return stub
+      end
+    end,
+
+    -- Make function calls safe (in case the stub itself is called)
+    __call = function()
+      return stub
+    end,
+  }
+
+  setmetatable(stub, metatable)
+  return stub
+end
+
+--- Safely require a module with graceful fallback for optional modules
+--- Returns the module if it exists, or a null-object stub if it's optional and missing
+--- Throws an error if a required module is missing
+---@param modulePath string Full path to the module (e.g., "modules.Performance")
+---@param isOptional boolean If true, returns null-object on failure; if false, throws error
+---@return table module The loaded module or a null-object stub
+function ModuleLoader.safeRequire(modulePath, isOptional)
+  -- Check if already loaded
+  if ModuleLoader._registry[modulePath] then
+    return ModuleLoader._registry[modulePath]
+  end
+
+  -- Attempt to load the module
+  local success, result = pcall(require, modulePath)
+
+  if success then
+    -- Module loaded successfully
+    ModuleLoader._registry[modulePath] = result
+    return result
+  else
+    -- Module failed to load
+    if isOptional then
+      -- Create null-object stub for optional module
+      local stub = createNullObject(modulePath)
+      ModuleLoader._registry[modulePath] = stub
+
+      -- Log warning about missing optional module
+      if ModuleLoader._ErrorHandler then
+        ModuleLoader._ErrorHandler:warn("ModuleLoader", "MOD_001", {
+          modulePath = modulePath,
+        })
+      end
+
+      return stub
+    else
+      -- Required module is missing - throw error
+      error(string.format("Required module '%s' not found: %s", modulePath, tostring(result)))
+    end
+  end
+end
+
+--- Check if a module is actually loaded (not a stub)
+---@param modulePath string Full path to the module
+---@return boolean isLoaded True if module is loaded, false if it's a stub or not loaded
+function ModuleLoader.isModuleLoaded(modulePath)
+  local module = ModuleLoader._registry[modulePath]
+  if not module then
+    return false
+  end
+
+  -- Check if it's a stub
+  return not module._isStub
+end
+
+--- Get list of all loaded modules
+---@return table modules List of module paths that are actually loaded (not stubs)
+function ModuleLoader.getLoadedModules()
+  local loaded = {}
+  for path, module in pairs(ModuleLoader._registry) do
+    if not module._isStub then
+      table.insert(loaded, path)
+    end
+  end
+  return loaded
+end
+
+--- Get list of all stub modules
+---@return table stubs List of module paths that are stubs
+function ModuleLoader.getStubModules()
+  local stubs = {}
+  for path, module in pairs(ModuleLoader._registry) do
+    if module._isStub then
+      table.insert(stubs, path)
+    end
+  end
+  return stubs
+end
+
+--- Clear the module registry (useful for testing)
+function ModuleLoader._clearRegistry()
+  ModuleLoader._registry = {}
+end
+
+return ModuleLoader

libs/flexlove/modules/NinePatch.lua

@@ -0,0 +1,217 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local ImageScaler = require(modulePath .. "ImageScaler")
+
+local NinePatch = {}
+
+-- ErrorHandler will be injected via init
+local ErrorHandler = nil
+
+--- Initialize NinePatch with dependencies
+---@param deps table Dependencies table with ErrorHandler
+function NinePatch.init(deps)
+  if deps and deps.ErrorHandler then
+    ErrorHandler = deps.ErrorHandler
+  end
+  -- Also initialize ImageScaler since it's a dependency
+  if ImageScaler.init then
+    ImageScaler.init(deps)
+  end
+end
+
+--- Draw a 9-patch component using Android-style rendering
+--- Corners are scaled by scaleCorners multiplier, edges stretch in one dimension only
+---@param component ThemeComponent
+---@param atlas love.Image
+---@param x number -- X position (top-left corner)
+---@param y number -- Y position (top-left corner)
+---@param width number -- Total width (border-box)
+---@param height number -- Total height (border-box)
+---@param opacity number?
+---@param elementScaleCorners number? -- Element-level override for scaleCorners (scale multiplier)
+---@param elementScalingAlgorithm "nearest"|"bilinear"? -- Element-level override for scalingAlgorithm
+function NinePatch.draw(component, atlas, x, y, width, height, opacity, elementScaleCorners, elementScalingAlgorithm)
+  if not component or not atlas then
+    return
+  end
+
+  opacity = opacity or 1
+  love.graphics.setColor(1, 1, 1, opacity)
+
+  local regions = component.regions
+
+  -- Extract border dimensions from regions (in pixels)
+  local left = regions.topLeft.w
+  local right = regions.topRight.w
+  local top = regions.topLeft.h
+  local bottom = regions.bottomLeft.h
+  local centerW = regions.middleCenter.w
+  local centerH = regions.middleCenter.h
+
+  -- Calculate content area (space remaining after borders)
+  local contentWidth = width - left - right
+  local contentHeight = height - top - bottom
+
+  -- Clamp to prevent negative dimensions
+  contentWidth = math.max(0, contentWidth)
+  contentHeight = math.max(0, contentHeight)
+
+  -- Calculate stretch scales for edges and center
+  local scaleX = contentWidth / centerW
+  local scaleY = contentHeight / centerH
+
+  -- Create quads for each region
+  local atlasWidth, atlasHeight = atlas:getDimensions()
+
+  local function makeQuad(region)
+    return love.graphics.newQuad(region.x, region.y, region.w, region.h, atlasWidth, atlasHeight)
+  end
+
+  -- Get corner scale multiplier
+  -- Priority: element-level override > component setting > default (nil = no scaling)
+  local scaleCorners = elementScaleCorners
+  if scaleCorners == nil then
+    scaleCorners = component.scaleCorners
+  end
+
+  -- Priority: element-level override > component setting > default ("bilinear")
+  local scalingAlgorithm = elementScalingAlgorithm
+  if scalingAlgorithm == nil then
+    scalingAlgorithm = component.scalingAlgorithm or "bilinear"
+  end
+
+  if scaleCorners and type(scaleCorners) == "number" and scaleCorners > 0 then
+    -- Initialize cache if needed
+    if not component._scaledRegionCache then
+      component._scaledRegionCache = {}
+    end
+
+    -- Use the numeric scale multiplier directly
+    local scaleFactor = scaleCorners
+
+    -- Helper to get or create scaled region
+    local function getScaledRegion(regionName, region, targetWidth, targetHeight)
+      local cacheKey = string.format("%s_%.2f_%s", regionName, scaleFactor, scalingAlgorithm)
+
+      if component._scaledRegionCache[cacheKey] then
+        return component._scaledRegionCache[cacheKey]
+      end
+
+      -- Get ImageData from component (stored during theme loading)
+      local atlasData = component._loadedAtlasData
+      if not atlasData then
+        ErrorHandler.error(
+          "NinePatch",
+          "REN_007",
+          "No ImageData available for atlas. Image must be loaded with safeLoadImage.",
+          {
+            componentType = component.type,
+          }
+        )
+      end
+
+      local scaledData
+
+      if scalingAlgorithm == "nearest" then
+        scaledData =
+          ImageScaler.scaleNearest(atlasData, region.x, region.y, region.w, region.h, targetWidth, targetHeight)
+      else
+        scaledData =
+          ImageScaler.scaleBilinear(atlasData, region.x, region.y, region.w, region.h, targetWidth, targetHeight)
+      end
+
+      -- Convert to image and cache
+      local scaledImage = love.graphics.newImage(scaledData)
+      component._scaledRegionCache[cacheKey] = scaledImage
+
+      return scaledImage
+    end
+
+    -- Calculate scaled dimensions for corners
+    local scaledLeft = math.floor(left * scaleFactor + 0.5)
+    local scaledRight = math.floor(right * scaleFactor + 0.5)
+    local scaledTop = math.floor(top * scaleFactor + 0.5)
+    local scaledBottom = math.floor(bottom * scaleFactor + 0.5)
+
+    -- CORNERS (scaled using algorithm)
+    local topLeftScaled = getScaledRegion("topLeft", regions.topLeft, scaledLeft, scaledTop)
+    local topRightScaled = getScaledRegion("topRight", regions.topRight, scaledRight, scaledTop)
+    local bottomLeftScaled = getScaledRegion("bottomLeft", regions.bottomLeft, scaledLeft, scaledBottom)
+    local bottomRightScaled = getScaledRegion("bottomRight", regions.bottomRight, scaledRight, scaledBottom)
+
+    love.graphics.draw(topLeftScaled, x, y)
+    love.graphics.draw(topRightScaled, x + width - scaledRight, y)
+    love.graphics.draw(bottomLeftScaled, x, y + height - scaledBottom)
+    love.graphics.draw(bottomRightScaled, x + width - scaledRight, y + height - scaledBottom)
+
+    -- Update content dimensions to account for scaled borders
+    local adjustedContentWidth = width - scaledLeft - scaledRight
+    local adjustedContentHeight = height - scaledTop - scaledBottom
+    adjustedContentWidth = math.max(0, adjustedContentWidth)
+    adjustedContentHeight = math.max(0, adjustedContentHeight)
+
+    -- Recalculate stretch scales
+    local adjustedScaleX = adjustedContentWidth / centerW
+    local adjustedScaleY = adjustedContentHeight / centerH
+
+    -- TOP/BOTTOM EDGES (stretch horizontally, scale vertically)
+    if adjustedContentWidth > 0 then
+      local topCenterScaled = getScaledRegion("topCenter", regions.topCenter, regions.topCenter.w, scaledTop)
+      local bottomCenterScaled =
+        getScaledRegion("bottomCenter", regions.bottomCenter, regions.bottomCenter.w, scaledBottom)
+
+      love.graphics.draw(topCenterScaled, x + scaledLeft, y, 0, adjustedScaleX, 1)
+      love.graphics.draw(bottomCenterScaled, x + scaledLeft, y + height - scaledBottom, 0, adjustedScaleX, 1)
+    end
+
+    -- LEFT/RIGHT EDGES (stretch vertically, scale horizontally)
+    if adjustedContentHeight > 0 then
+      local middleLeftScaled = getScaledRegion("middleLeft", regions.middleLeft, scaledLeft, regions.middleLeft.h)
+      local middleRightScaled = getScaledRegion("middleRight", regions.middleRight, scaledRight, regions.middleRight.h)
+
+      love.graphics.draw(middleLeftScaled, x, y + scaledTop, 0, 1, adjustedScaleY)
+      love.graphics.draw(middleRightScaled, x + width - scaledRight, y + scaledTop, 0, 1, adjustedScaleY)
+    end
+
+    -- CENTER (stretch both dimensions, no scaling)
+    if adjustedContentWidth > 0 and adjustedContentHeight > 0 then
+      love.graphics.draw(
+        atlas,
+        makeQuad(regions.middleCenter),
+        x + scaledLeft,
+        y + scaledTop,
+        0,
+        adjustedScaleX,
+        adjustedScaleY
+      )
+    end
+  else
+    -- Original rendering logic (no scaling)
+    -- CORNERS (no scaling - 1:1 pixel perfect)
+    love.graphics.draw(atlas, makeQuad(regions.topLeft), x, y)
+    love.graphics.draw(atlas, makeQuad(regions.topRight), x + left + contentWidth, y)
+    love.graphics.draw(atlas, makeQuad(regions.bottomLeft), x, y + top + contentHeight)
+    love.graphics.draw(atlas, makeQuad(regions.bottomRight), x + left + contentWidth, y + top + contentHeight)
+
+    -- TOP/BOTTOM EDGES (stretch horizontally only)
+    if contentWidth > 0 then
+      love.graphics.draw(atlas, makeQuad(regions.topCenter), x + left, y, 0, scaleX, 1)
+      love.graphics.draw(atlas, makeQuad(regions.bottomCenter), x + left, y + top + contentHeight, 0, scaleX, 1)
+    end
+
+    -- LEFT/RIGHT EDGES (stretch vertically only)
+    if contentHeight > 0 then
+      love.graphics.draw(atlas, makeQuad(regions.middleLeft), x, y + top, 0, 1, scaleY)
+      love.graphics.draw(atlas, makeQuad(regions.middleRight), x + left + contentWidth, y + top, 0, 1, scaleY)
+    end
+
+    -- CENTER (stretch both dimensions)
+    if contentWidth > 0 and contentHeight > 0 then
+      love.graphics.draw(atlas, makeQuad(regions.middleCenter), x + left, y + top, 0, scaleX, scaleY)
+    end
+  end
+
+  -- Reset color
+  love.graphics.setColor(1, 1, 1, 1)
+end
+
+return NinePatch

libs/flexlove/modules/NumberValidation.lua

@@ -0,0 +1,351 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+-- All numeric, range, type, and enum validation lives here.
+-- `clamp` is injected via init() to avoid a cross-import into utils.
+-- `ErrorHandler` is injected via init() so error reporting routes through
+-- the shared handler (matching the pre-split behavior of utils.validate*).
+
+local ErrorHandler = nil
+local clamp = nil
+
+--- Initialize dependencies
+---@param deps table Dependencies: { ErrorHandler = table, clamp = function }
+local function init(deps)
+  if type(deps) == "table" then
+    ErrorHandler = deps.ErrorHandler or ErrorHandler
+    clamp = deps.clamp or clamp
+  end
+end
+
+-- Numeric validation utilities
+
+--- Check if a value is NaN (not-a-number)
+--- @param value any Value to check
+--- @return boolean
+local function isNaN(value)
+  return type(value) == "number" and value ~= value
+end
+
+--- Check if a value is Infinity
+--- @param value any Value to check
+--- @return boolean
+local function isInfinity(value)
+  return type(value) == "number" and (value == math.huge or value == -math.huge)
+end
+
+--- Validate a numeric value with comprehensive checks
+--- @param value any Value to validate
+--- @param options table? Validation options
+--- @return boolean, string?, number? Returns valid, errorMessage, sanitizedValue
+local function validateNumber(value, options)
+  options = options or {}
+
+  -- Check if value is a number type
+  if type(value) ~= "number" then
+    if options.default ~= nil then
+      return true, nil, options.default
+    end
+    return false, string.format("Value must be a number, got %s", type(value)), nil
+  end
+
+  -- Check for NaN
+  if isNaN(value) then
+    if not options.allowNaN then
+      if options.default ~= nil then
+        return true, nil, options.default
+      end
+      return false, "Value is NaN (not-a-number)", nil
+    end
+  end
+
+  -- Check for Infinity
+  if isInfinity(value) then
+    if not options.allowInfinity then
+      if options.default ~= nil then
+        return true, nil, options.default
+      end
+      return false, "Value is Infinity", nil
+    end
+  end
+
+  -- Check for integer requirement
+  if options.integer and math.floor(value) ~= value then
+    return false, string.format("Value must be an integer, got %s", value), nil
+  end
+
+  -- Check for positive requirement
+  if options.positive and value <= 0 then
+    return false, string.format("Value must be positive, got %s", value), nil
+  end
+
+  -- Check bounds
+  if options.min and value < options.min then
+    return false, string.format("Value %s is below minimum %s", value, options.min), nil
+  end
+
+  if options.max and value > options.max then
+    return false, string.format("Value %s is above maximum %s", value, options.max), nil
+  end
+
+  return true, nil, value
+end
+
+--- Sanitize a numeric value (never errors, always returns valid number)
+--- @param value any Value to sanitize
+--- @param min number? Minimum value
+--- @param max number? Maximum value
+--- @param default number? Default value for invalid inputs
+--- @return number Sanitized value
+local function sanitizeNumber(value, min, max, default)
+  default = default or 0
+  min = min or -math.huge
+  max = max or math.huge
+
+  -- Convert to number if possible
+  if type(value) == "string" then
+    value = tonumber(value)
+  end
+
+  -- Handle non-numeric
+  if type(value) ~= "number" then
+    return default
+  end
+
+  -- Handle NaN
+  if isNaN(value) then
+    return default
+  end
+
+  -- Handle Infinity
+  if value == math.huge then
+    return max
+  end
+  if value == -math.huge then
+    return min
+  end
+
+  -- Clamp to range
+  return clamp(value, min, max)
+end
+
+--- Validate and convert to integer
+--- @param value any Value to validate
+--- @param min number? Minimum value
+--- @param max number? Maximum value
+--- @return boolean, string?, number? Returns valid, errorMessage, integerValue
+local function validateInteger(value, min, max)
+  local valid, err, sanitized = validateNumber(value, {
+    min = min,
+    max = max,
+    integer = true,
+  })
+
+  if not valid then
+    return false, err, nil
+  end
+
+  return true, nil, math.floor(sanitized or value)
+end
+
+--- Validate and normalize percentage value
+--- @param value any Value to validate (can be "50%", 0.5, or 50)
+--- @return boolean, string?, number? Returns valid, errorMessage, normalizedValue (0-1)
+local function validatePercentage(value)
+  -- Handle string percentage
+  if type(value) == "string" then
+    local num = value:match("^(%d+%.?%d*)%%$")
+    if num then
+      value = tonumber(num)
+      if value then
+        value = value / 100
+      end
+    else
+      value = tonumber(value)
+    end
+  end
+
+  if type(value) ~= "number" then
+    return false, "Percentage must be a number", nil
+  end
+
+  if isNaN(value) or isInfinity(value) then
+    return false, "Percentage cannot be NaN or Infinity", nil
+  end
+
+  -- If value is > 1, assume it's 0-100 range
+  if value > 1 then
+    value = value / 100
+  end
+
+  -- Clamp to 0-1
+  value = clamp(value, 0, 1)
+
+  return true, nil, value
+end
+
+--- Validate opacity value (0-1)
+--- @param value any Value to validate
+--- @return boolean, string?, number? Returns valid, errorMessage, opacityValue
+local function validateOpacity(value)
+  return validateNumber(value, { min = 0, max = 1, default = 1 })
+end
+
+--- Validate degree value (0-360)
+--- @param value any Value to validate
+--- @return boolean, string?, number? Returns valid, errorMessage, degreeValue
+local function validateDegrees(value)
+  local valid, err, sanitized = validateNumber(value)
+  if not valid then
+    return false, err, nil
+  end
+
+  -- Normalize to 0-360 range
+  local degrees = sanitized or value
+  degrees = degrees % 360
+  if degrees < 0 then
+    degrees = degrees + 360
+  end
+
+  return true, nil, degrees
+end
+
+--- Validate coordinate value (pixel position)
+--- @param value any Value to validate
+--- @return boolean, string?, number? Returns valid, errorMessage, coordinateValue
+local function validateCoordinate(value)
+  return validateNumber(value, {
+    allowNaN = false,
+    allowInfinity = false,
+  })
+end
+
+--- Validate dimension value (width/height, must be non-negative)
+--- @param value any Value to validate
+--- @return boolean, string?, number? Returns valid, errorMessage, dimensionValue
+local function validateDimension(value)
+  return validateNumber(value, {
+    min = 0,
+    allowNaN = false,
+    allowInfinity = false,
+  })
+end
+
+--- Validate that a value is in an enum table
+---@param value any Value to validate
+---@param enumTable table Enum table with valid values
+---@param propName string Property name for error messages
+---@param moduleName string? Module name for error messages (default: "Element")
+---@return boolean True if valid
+local function validateEnum(value, enumTable, propName, moduleName)
+  if value == nil then
+    return true
+  end
+
+  for _, validValue in pairs(enumTable) do
+    if value == validValue then
+      return true
+    end
+  end
+
+  -- Build list of valid options
+  local validOptions = {}
+  for _, v in pairs(enumTable) do
+    table.insert(validOptions, "'" .. v .. "'")
+  end
+  table.sort(validOptions)
+
+  if ErrorHandler then
+    ErrorHandler:error(moduleName or "Element", "VAL_007", {
+      property = propName,
+      expected = table.concat(validOptions, ", "),
+      got = tostring(value),
+    })
+  else
+    error(
+      string.format("%s must be one of: %s. Got: '%s'", propName, table.concat(validOptions, ", "), tostring(value))
+    )
+  end
+end
+
+--- Validate that a numeric value is within a range
+---@param value any Value to validate
+---@param min number Minimum allowed value
+---@param max number Maximum allowed value
+---@param propName string Property name for error messages
+---@param moduleName string? Module name for error messages (default: "Element")
+---@return boolean True if valid
+local function validateRange(value, min, max, propName, moduleName)
+  if value == nil then
+    return true
+  end
+  if type(value) ~= "number" then
+    if ErrorHandler then
+      ErrorHandler:error(moduleName or "Element", "VAL_001", {
+        property = propName,
+        expected = "number",
+        got = type(value),
+      })
+    else
+      error(string.format("%s must be a number, got %s", propName, type(value)))
+    end
+  elseif value < min or value > max then
+    if ErrorHandler then
+      ErrorHandler:error(moduleName or "Element", "VAL_002", {
+        property = propName,
+        min = tostring(min),
+        max = tostring(max),
+        value = tostring(value),
+      })
+    else
+      error(
+        string.format("%s must be between %s and %s, got %s", propName, tostring(min), tostring(max), tostring(value))
+      )
+    end
+  end
+  return true
+end
+
+--- Validate that a value is of the expected type
+---@param value any Value to validate
+---@param expectedType string Expected type name
+---@param propName string Property name for error messages
+---@param moduleName string? Module name for error messages (default: "Element")
+---@return boolean True if valid
+local function validateType(value, expectedType, propName, moduleName)
+  if value == nil then
+    return true
+  end
+  local actualType = type(value)
+  if actualType ~= expectedType then
+    if ErrorHandler then
+      ErrorHandler:error(moduleName or "Element", "VAL_001", {
+        property = propName,
+        expected = expectedType,
+        got = actualType,
+      })
+    else
+      error(string.format("%s must be %s, got %s", propName, expectedType, actualType))
+    end
+  end
+  return true
+end
+
+return {
+  init = init,
+  isNaN = isNaN,
+  isInfinity = isInfinity,
+  validateNumber = validateNumber,
+  sanitizeNumber = sanitizeNumber,
+  validateInteger = validateInteger,
+  validatePercentage = validatePercentage,
+  validateOpacity = validateOpacity,
+  validateDegrees = validateDegrees,
+  validateCoordinate = validateCoordinate,
+  validateDimension = validateDimension,
+  validateEnum = validateEnum,
+  validateRange = validateRange,
+  validateType = validateType,
+}

libs/flexlove/modules/PathValidator.lua

@@ -0,0 +1,198 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+-- Path sanitization, validation, and file-extension helpers.
+-- Uses love.filesystem when available (optional) for existence checks.
+
+--- Normalize a file path for consistent cache keys
+---@param path string File path to normalize
+---@return string Normalized path
+local function normalizePath(path)
+  path = path:match("^%s*(.-)%s*$")
+  path = path:gsub("\\", "/")
+  path = path:gsub("/+", "/")
+  return path
+end
+
+--- Sanitize a file path
+--- @param path string Path to sanitize
+--- @return string Sanitized path
+local function sanitizePath(path)
+  if path == nil then
+    return ""
+  end
+  path = tostring(path)
+
+  -- Trim whitespace
+  path = path:match("^%s*(.-)%s*$") or ""
+
+  -- Normalize separators to forward slash
+  path = path:gsub("\\", "/")
+
+  -- Remove duplicate slashes
+  path = path:gsub("/+", "/")
+
+  -- Remove trailing slash (except for root)
+  if #path > 1 and path:sub(-1) == "/" then
+    path = path:sub(1, -2)
+  end
+
+  return path
+end
+
+--- Check if a path is safe (no traversal attacks)
+--- @param path string Path to check
+--- @param baseDir string? Base directory to check against (optional)
+--- @return boolean, string? Returns true if safe, or false with reason
+local function isPathSafe(path, baseDir)
+  if path == nil or path == "" then
+    return false, "Path is empty"
+  end
+
+  -- Sanitize the path
+  path = sanitizePath(path)
+
+  -- Check for suspicious patterns
+  if path:match("%.%.") then
+    return false, "Path contains '..' (parent directory reference)"
+  end
+
+  -- Check for null bytes
+  if path:match("%z") then
+    return false, "Path contains null bytes"
+  end
+
+  -- Check for encoded traversal attempts (including double-encoding)
+  local lowerPath = path:lower()
+  if
+    lowerPath:match("%%2e")
+    or lowerPath:match("%%2f")
+    or lowerPath:match("%%5c")
+    or lowerPath:match("%%252e")
+    or lowerPath:match("%%252f")
+    or lowerPath:match("%%255c")
+  then
+    return false, "Path contains URL-encoded directory separators"
+  end
+
+  -- If baseDir is provided, ensure path is within it
+  if baseDir then
+    baseDir = sanitizePath(baseDir)
+
+    -- For relative paths, prepend baseDir
+    local fullPath = path
+    if not path:match("^/") and not path:match("^%a:") then
+      fullPath = baseDir .. "/" .. path
+    end
+    fullPath = sanitizePath(fullPath)
+
+    -- Check if fullPath starts with baseDir
+    if not fullPath:match("^" .. baseDir:gsub("[%(%)%.%%%+%-%*%?%[%]%^%$]", "%%%1")) then
+      return false, "Path is outside allowed directory"
+    end
+  end
+
+  return true, nil
+end
+
+--- Validate a file path with comprehensive checks
+--- @param path string Path to validate
+--- @param options table? Validation options
+--- @return boolean, string? Returns true if valid, or false with error message
+local function validatePath(path, options)
+  options = options or {}
+
+  -- Check path is not nil/empty
+  if path == nil or path == "" then
+    return false, "Path is empty"
+  end
+
+  path = tostring(path)
+
+  -- Check maximum length
+  local maxLength = options.maxLength or 4096
+  if #path > maxLength then
+    return false, string.format("Path exceeds maximum length of %d characters", maxLength)
+  end
+
+  -- Sanitize path
+  path = sanitizePath(path)
+
+  -- Check for safety (traversal attacks)
+  local safe, reason = isPathSafe(path, options.baseDir)
+  if not safe then
+    return false, reason
+  end
+
+  -- Check allowed extensions
+  if options.allowedExtensions then
+    local ext = path:match("%.([^%.]+)$")
+    if not ext then
+      return false, "Path has no file extension"
+    end
+
+    ext = ext:lower()
+    local allowed = false
+    for _, allowedExt in ipairs(options.allowedExtensions) do
+      if ext == allowedExt:lower() then
+        allowed = true
+        break
+      end
+    end
+
+    if not allowed then
+      return false, string.format("File extension '%s' is not allowed", ext)
+    end
+  end
+
+  -- Check if file must exist
+  if options.mustExist and love and love.filesystem then
+    local info = love.filesystem.getInfo(path)
+    if not info then
+      return false, "File does not exist"
+    end
+  end
+
+  return true, nil
+end
+
+--- Get file extension from path
+--- @param path string File path
+--- @return string? extension File extension (lowercase) or nil
+local function getFileExtension(path)
+  if not path then
+    return nil
+  end
+  local ext = path:match("%.([^%.]+)$")
+  return ext and ext:lower() or nil
+end
+
+--- Check if path has allowed extension
+--- @param path string File path
+--- @param allowedExtensions table Array of allowed extensions
+--- @return boolean
+local function hasAllowedExtension(path, allowedExtensions)
+  local ext = getFileExtension(path)
+  if not ext then
+    return false
+  end
+
+  for _, allowedExt in ipairs(allowedExtensions) do
+    if ext == allowedExt:lower() then
+      return true
+    end
+  end
+
+  return false
+end
+
+return {
+  normalizePath = normalizePath,
+  sanitizePath = sanitizePath,
+  isPathSafe = isPathSafe,
+  validatePath = validatePath,
+  getFileExtension = getFileExtension,
+  hasAllowedExtension = hasAllowedExtension,
+}

libs/flexlove/modules/Performance.lua

@@ -0,0 +1,560 @@
+---@class Performance
+---@field enabled boolean
+---@field hudEnabled boolean
+---@field hudToggleKey string
+---@field hudPosition {x: number, y: number}
+---@field warningThresholdMs number
+---@field criticalThresholdMs number
+---@field logToConsole boolean
+---@field logWarnings boolean
+---@field warningsEnabled boolean
+---@field _ErrorHandler table?
+---@field _timers table
+---@field _metrics table
+---@field _lastMetricsCleanup number
+---@field _frameMetrics table
+---@field _memoryMetrics table
+---@field _warnings table
+---@field _lastFrameStart number?
+---@field _shownWarnings table
+---@field _memoryProfiler table
+local Performance = {}
+Performance.__index = Performance
+
+---@type Performance|nil
+local instance = nil
+
+local METRICS_CLEANUP_INTERVAL = 30
+local METRICS_RETENTION_TIME = 10
+local MAX_METRICS_COUNT = 500
+local CORE_METRICS = { frame = true, layout = true, render = true }
+
+---@param config {enabled?: boolean, hudEnabled?: boolean, hudToggleKey?: string, hudPosition?: {x: number, y: number}, warningThresholdMs?: number, criticalThresholdMs?: number, logToConsole?: boolean, logWarnings?: boolean, warningsEnabled?: boolean, memoryProfiling?: boolean}?
+---@param deps {ErrorHandler: ErrorHandler}
+---@return Performance
+function Performance.init(config, deps)
+  if instance == nil then
+    local self = setmetatable({}, Performance)
+
+    -- Configuration
+    self.enabled = config and config.enabled or false
+    self.hudEnabled = config and config.hudEnabled or false
+    self.hudToggleKey = config and config.hudToggleKey or "f3"
+    self.hudPosition = config and config.hudPosition or { x = 10, y = 10 }
+    self.warningThresholdMs = config and config.warningThresholdMs or 13.0
+    self.criticalThresholdMs = config and config.criticalThresholdMs or 16.67
+    self.logToConsole = config and config.logToConsole or false
+    self.logWarnings = config and config.logWarnings or true
+    self.warningsEnabled = config and config.warningsEnabled or true
+
+    self._timers = {}
+    self._metrics = {}
+    self._lastMetricsCleanup = 0
+    self._frameMetrics = {
+      frameCount = 0,
+      totalTime = 0,
+      lastFrameTime = 0,
+      minFrameTime = math.huge,
+      maxFrameTime = 0,
+      fps = 0,
+      lastFpsUpdate = 0,
+      fpsUpdateInterval = 0.5,
+    }
+    self._memoryMetrics = {
+      current = 0,
+      peak = 0,
+      gcCount = 0,
+      lastGcCheck = 0,
+    }
+    self._warnings = {}
+    self._lastFrameStart = nil
+    self._shownWarnings = {}
+    self._memoryProfiler = {
+      enabled = config and config.memoryProfiling or false,
+      sampleInterval = 60,
+      framesSinceLastSample = 0,
+      samples = {},
+      maxSamples = 20,
+      monitoredTables = {},
+    }
+    self._ErrorHandler = deps and deps.ErrorHandler
+    instance = self
+  end
+  return instance
+end
+
+--- Toggle HUD visibility
+function Performance:toggleHUD()
+  self.hudEnabled = not self.hudEnabled
+end
+
+function Performance:startTimer(name)
+  if not self.enabled then
+    return
+  end
+  self._timers[name] = love.timer.getTime()
+end
+
+function Performance:stopTimer(name)
+  if not self.enabled then
+    return nil
+  end
+
+  local startTime = self._timers[name]
+  if not startTime then
+    -- Silently return nil if timer wasn't started
+    -- This can happen legitimately when Performance is toggled mid-frame
+    -- or when layout functions have early returns
+    return nil
+  end
+
+  local elapsed = (love.timer.getTime() - startTime) * 1000
+  self._timers[name] = nil
+
+  -- Update metrics
+  if not self._metrics[name] then
+    self._metrics[name] = {
+      total = 0,
+      count = 0,
+      min = math.huge,
+      max = 0,
+      average = 0,
+      lastUsed = love.timer.getTime(),
+    }
+  end
+
+  local m = self._metrics[name]
+  m.total = m.total + elapsed
+  m.count = m.count + 1
+  m.min = math.min(m.min, elapsed)
+  m.max = math.max(m.max, elapsed)
+  m.average = m.total / m.count
+  m.lastUsed = love.timer.getTime()
+
+  -- Check for warnings
+  if elapsed > self.criticalThresholdMs then
+    self:_addWarning(name, elapsed, "critical")
+  elseif elapsed > self.warningThresholdMs then
+    self:_addWarning(name, elapsed, "warning")
+  end
+
+  if self.logToConsole then
+    -- Use ErrorHandler if available, otherwise fall back to print
+    if self._ErrorHandler and self._ErrorHandler.warn then
+      self._ErrorHandler:warn("Performance", "PERF_001", {
+        metric = name,
+        elapsed = string.format("%.3fms", elapsed),
+      })
+    else
+      print(string.format("[Performance] %s: %.3fms", name, elapsed))
+    end
+  end
+
+  return elapsed
+end
+
+--- Update with actual delta time from LÖVE (call from love.update)
+---@param dt number Delta time in seconds
+function Performance:updateDeltaTime(dt)
+  if not self.enabled then
+    return
+  end
+  local now = love.timer.getTime()
+  if now - self._frameMetrics.lastFpsUpdate >= self._frameMetrics.fpsUpdateInterval then
+    if dt > 0 then
+      self._frameMetrics.fps = math.floor(1 / dt + 0.5)
+    end
+    self._frameMetrics.lastFpsUpdate = now
+  end
+end
+
+--- Start frame timing (call at beginning of frame)
+function Performance:startFrame()
+  if not self.enabled then
+    return
+  end
+  self._lastFrameStart = love.timer.getTime()
+  self:_updateMemory()
+end
+
+function Performance:endFrame()
+  if not self.enabled or not self._lastFrameStart then
+    return
+  end
+
+  local now = love.timer.getTime()
+  local frameTime = (now - self._lastFrameStart) * 1000
+
+  self._frameMetrics.lastFrameTime = frameTime
+  self._frameMetrics.totalTime = self._frameMetrics.totalTime + frameTime
+  self._frameMetrics.frameCount = self._frameMetrics.frameCount + 1
+  self._frameMetrics.minFrameTime = math.min(self._frameMetrics.minFrameTime, frameTime)
+  self._frameMetrics.maxFrameTime = math.max(self._frameMetrics.maxFrameTime, frameTime)
+
+  if frameTime > self.criticalThresholdMs then
+    self:_addWarning("frame", frameTime, "critical")
+  end
+
+  self:updateMemoryProfiling()
+
+  -- Periodic metrics cleanup
+  if now - self._lastMetricsCleanup >= METRICS_CLEANUP_INTERVAL then
+    local cleanupTime = now - METRICS_RETENTION_TIME
+    for name, data in pairs(self._metrics) do
+      if not CORE_METRICS[name] and data.lastUsed and data.lastUsed < cleanupTime then
+        self._metrics[name] = nil
+      end
+    end
+    self._lastMetricsCleanup = now
+  end
+
+  -- Enforce max metrics limit
+  local metricsCount = 0
+  for _ in pairs(self._metrics) do
+    metricsCount = metricsCount + 1
+  end
+
+  if metricsCount > MAX_METRICS_COUNT then
+    local sortedMetrics = {}
+    for name, data in pairs(self._metrics) do
+      if not CORE_METRICS[name] then
+        table.insert(sortedMetrics, { name = name, lastUsed = data.lastUsed or 0 })
+      end
+    end
+
+    table.sort(sortedMetrics, function(a, b)
+      return a.lastUsed < b.lastUsed
+    end)
+
+    local toRemove = metricsCount - MAX_METRICS_COUNT
+    for i = 1, math.min(toRemove, #sortedMetrics) do
+      self._metrics[sortedMetrics[i].name] = nil
+    end
+  end
+end
+
+--- Update memory metrics
+function Performance:_updateMemory()
+  if not self.enabled then
+    return
+  end
+
+  local memKb = collectgarbage("count")
+  self._memoryMetrics.current = memKb
+  self._memoryMetrics.peak = math.max(self._memoryMetrics.peak, memKb)
+
+  local now = love.timer.getTime()
+  if now - self._memoryMetrics.lastGcCheck >= 1.0 then
+    self._memoryMetrics.gcCount = self._memoryMetrics.gcCount + 1
+    self._memoryMetrics.lastGcCheck = now
+  end
+end
+
+--- Add a performance warning (private)
+--- @param name string Metric name
+--- @param value number Metric value
+--- @param level "warning"|"critical" Warning level
+function Performance:_addWarning(name, value, level)
+  if not self.logWarnings then
+    return
+  end
+
+  local warning = {
+    name = name,
+    value = value,
+    level = level,
+    time = love.timer.getTime(),
+  }
+
+  table.insert(self._warnings, warning)
+
+  if #self._warnings > 100 then
+    table.remove(self._warnings, 1)
+  end
+
+  if self.logToConsole or self.warningsEnabled then
+    local warningKey = name .. "_" .. level
+    local lastWarningTime = self._shownWarnings[warningKey] or 0
+    local now = love.timer.getTime()
+
+    if now - lastWarningTime >= 60 then
+      if self._ErrorHandler and self._ErrorHandler.warn then
+        local code = level == "critical" and "PERF_002" or "PERF_001"
+
+        self._ErrorHandler:warn("Performance", code, {
+          metric = name,
+          value = string.format("%.2fms", value),
+          threshold = level == "critical" and self.criticalThresholdMs or self.warningThresholdMs,
+        })
+      end
+
+      self._shownWarnings[warningKey] = now
+    end
+  end
+end
+
+--- Render performance HUD
+--- @param x number? X position (default: 10)
+--- @param y number? Y position (default: 10)
+function Performance:renderHUD(x, y)
+  if not self.hudEnabled then
+    return
+  end
+
+  x = x or self.hudPosition.x
+  y = y or self.hudPosition.y
+
+  self:_updateMemory()
+
+  local fm = self._frameMetrics
+  local mm = self._memoryMetrics
+
+  love.graphics.setColor(0, 0, 0, 0.8)
+  love.graphics.rectangle("fill", x, y, 300, 220)
+
+  love.graphics.setColor(1, 1, 1, 1)
+  local lineHeight = 18
+  local currentY = y + 10
+
+  -- FPS
+  local fpsColor = { 1, 1, 1 }
+  if fm.lastFrameTime > self.criticalThresholdMs then
+    fpsColor = { 1, 0, 0 }
+  elseif fm.lastFrameTime > self.warningThresholdMs then
+    fpsColor = { 1, 1, 0 }
+  end
+  love.graphics.setColor(fpsColor)
+  love.graphics.print(string.format("FPS: %d (%.2fms)", fm.fps, fm.lastFrameTime), x + 10, currentY)
+  currentY = currentY + lineHeight
+
+  love.graphics.setColor(1, 1, 1, 1)
+  local avgFrame = fm.frameCount > 0 and fm.totalTime / fm.frameCount or 0
+  love.graphics.print(string.format("Avg Frame: %.2fms", avgFrame), x + 10, currentY)
+  currentY = currentY + lineHeight
+  love.graphics.print(string.format("Min/Max: %.2f/%.2fms", fm.minFrameTime, fm.maxFrameTime), x + 10, currentY)
+  currentY = currentY + lineHeight
+
+  local currentMb = mm.current / 1024
+  local peakMb = mm.peak / 1024
+  love.graphics.print(string.format("Memory: %.2f MB (peak: %.2f MB)", currentMb, peakMb), x + 10, currentY)
+  currentY = currentY + lineHeight
+
+  local metricsCount = 0
+  for _ in pairs(self._metrics) do
+    metricsCount = metricsCount + 1
+  end
+  local metricsColor = metricsCount > MAX_METRICS_COUNT * 0.8 and { 1, 0.5, 0 } or { 1, 1, 1 }
+  love.graphics.setColor(metricsColor)
+  love.graphics.print(string.format("Metrics: %d/%d", metricsCount, MAX_METRICS_COUNT), x + 10, currentY)
+  currentY = currentY + lineHeight + 5
+
+  -- Top timings
+  love.graphics.setColor(1, 1, 1, 1)
+  local sortedMetrics = {}
+  for name, data in pairs(self._metrics) do
+    table.insert(sortedMetrics, { name = name, average = data.average })
+  end
+  table.sort(sortedMetrics, function(a, b)
+    return a.average > b.average
+  end)
+
+  love.graphics.print("Top Timings:", x + 10, currentY)
+  currentY = currentY + lineHeight
+
+  for i = 1, math.min(5, #sortedMetrics) do
+    local m = sortedMetrics[i]
+    love.graphics.print(string.format("  %s: %.3fms", m.name, m.average), x + 10, currentY)
+    currentY = currentY + lineHeight
+  end
+
+  if #self._warnings > 0 then
+    love.graphics.setColor(1, 0.5, 0, 1)
+    love.graphics.print(string.format("Warnings: %d", #self._warnings), x + 10, currentY)
+  end
+end
+
+--- Handle keyboard input for HUD toggle
+--- @param key string Key pressed
+function Performance:keypressed(key)
+  if key == self.hudToggleKey then
+    self:toggleHUD()
+  end
+end
+
+--- Log a performance warning (only once per warning key)
+--- @param warningKey string Unique key for this warning type
+--- @param module string Module name (e.g., "LayoutEngine", "Element")
+--- @param message string Warning message
+--- @param details table? Additional details
+--- @param suggestion string? Optimization suggestion
+function Performance:logWarning(warningKey, module, message, details, suggestion)
+  if not self.warningsEnabled then
+    return
+  end
+
+  if self._shownWarnings[warningKey] then
+    return
+  end
+
+  self._shownWarnings[warningKey] = true
+
+  local count = 0
+  for _ in pairs(self._shownWarnings) do
+    count = count + 1
+  end
+  if count > 1000 then
+    self._shownWarnings = { [warningKey] = true }
+  end
+
+  if self._ErrorHandler and self._ErrorHandler.warn then
+    self._ErrorHandler:warn(module, "PERF_001", details or {})
+  end
+end
+
+--- Track a counter metric (increments per frame)
+--- @param name string Counter name
+--- @param value number? Value to add (default: 1)
+function Performance:incrementCounter(name, value)
+  if not self.enabled then
+    return
+  end
+
+  value = value or 1
+
+  if not self._metrics[name] then
+    self._metrics[name] = {
+      total = 0,
+      count = 0,
+      min = math.huge,
+      max = 0,
+      average = 0,
+      frameValue = 0,
+      lastUsed = love.timer.getTime(),
+    }
+  end
+
+  local m = self._metrics[name]
+  m.frameValue = (m.frameValue or 0) + value
+  m.lastUsed = love.timer.getTime()
+end
+
+--- Reset frame counters (call at end of frame)
+function Performance:resetFrameCounters()
+  if not self.enabled then
+    return
+  end
+
+  local now = love.timer.getTime()
+  local toRemove = {}
+
+  for name, data in pairs(self._metrics) do
+    if data.frameValue then
+      if data.frameValue > 0 then
+        data.total = data.total + data.frameValue
+        data.count = data.count + 1
+        data.min = math.min(data.min, data.frameValue)
+        data.max = math.max(data.max, data.frameValue)
+        data.average = data.total / data.count
+        data.lastUsed = now
+      end
+
+      data.frameValue = 0
+
+      if data.count == 0 and not CORE_METRICS[name] then
+        table.insert(toRemove, name)
+      end
+    end
+  end
+
+  for _, name in ipairs(toRemove) do
+    self._metrics[name] = nil
+  end
+end
+
+--- Register a table for memory leak monitoring
+--- @param name string Friendly name for the table
+--- @param tableRef table Reference to the table to monitor
+function Performance:registerTableForMonitoring(name, tableRef)
+  self._memoryProfiler.monitoredTables[name] = tableRef
+end
+
+function Performance:_sampleMemory()
+  local sample = {
+    time = love.timer.getTime(),
+    memory = collectgarbage("count") / 1024, -- MB
+    tableSizes = {},
+  }
+  local function getTableSize(tbl)
+    local count = 0
+    for _ in pairs(tbl) do
+      count = count + 1
+    end
+    return count
+  end
+
+  for name, tableRef in pairs(self._memoryProfiler.monitoredTables) do
+    sample.tableSizes[name] = getTableSize(tableRef)
+  end
+
+  table.insert(self._memoryProfiler.samples, sample)
+
+  -- Keep only maxSamples
+  if #self._memoryProfiler.samples > self._memoryProfiler.maxSamples then
+    table.remove(self._memoryProfiler.samples, 1)
+  end
+
+  -- Check for memory leaks (consistent growth)
+  if #self._memoryProfiler.samples >= 5 then
+    for name, _ in pairs(self._memoryProfiler.monitoredTables) do
+      local sizes = {}
+      for i = math.max(1, #self._memoryProfiler.samples - 4), #self._memoryProfiler.samples do
+        table.insert(sizes, self._memoryProfiler.samples[i].tableSizes[name])
+      end
+
+      -- Check if table is consistently growing
+      local growing = true
+      for i = 2, #sizes do
+        if sizes[i] <= sizes[i - 1] then
+          growing = false
+          break
+        end
+      end
+
+      if growing and sizes[#sizes] > sizes[1] * 1.5 then
+        self:_addWarning("memory_leak", sizes[#sizes], "warning")
+
+        if not self._shownWarnings[name] then
+          local message = string.format("Table '%s' growing consistently", name)
+          if self._ErrorHandler and self._ErrorHandler.warn then
+            self._ErrorHandler:warn("Performance", "MEM_001", {
+              table = name,
+              initialSize = sizes[1],
+              currentSize = sizes[#sizes],
+              growthPercent = math.floor(((sizes[#sizes] / sizes[1]) - 1) * 100),
+            })
+          end
+
+          self._shownWarnings[name] = true
+        end
+      elseif not growing then
+        self._shownWarnings[name] = nil
+      end
+    end
+  end
+end
+
+--- Update memory profiling (call from endFrame)
+function Performance:updateMemoryProfiling()
+  if not self._memoryProfiler.enabled then
+    return
+  end
+
+  self._memoryProfiler.framesSinceLastSample = self._memoryProfiler.framesSinceLastSample + 1
+
+  if self._memoryProfiler.framesSinceLastSample >= self._memoryProfiler.sampleInterval then
+    self:_sampleMemory()
+    self._memoryProfiler.framesSinceLastSample = 0
+  end
+end
+
+return Performance

libs/flexlove/modules/PropertySchema.lua

@@ -0,0 +1,505 @@
+-- modules/PropertySchema.lua
+--
+-- Declarative source of truth for every Element prop.
+--
+-- Each entry describes one prop that Element.new / Element:setProperty currently
+-- handles inline. Downstream tasks (03 data-driven prop binding, 05 registry-driven
+-- setProperty dispatch) read this metadata instead of hardcoding property names.
+--
+-- Design constraints (locked — tasks 03/05 depend on this API):
+--   * Pure Lua — NO `love` import, NO dependency on utils/Color/Units/ErrorHandler.
+--     Normalizers/validators are small, dependency-free closures so the module is
+--     unit-testable standalone. Color/^/unit/enum *defaults* that require those
+--     modules are left as `nil` here and applied by construction-time special
+--     handlers in Task 03; only defaults expressible as literals are stored.
+--   * O(1) lookup — `get(name)` is a single table index into a pre-built registry;
+--     no per-call construction.
+--   * Additive — `define(specs)` merges entries by name so build profiles can
+--     extend/override without rebuilding the whole table.
+--
+-- Metadata shape per prop (all fields present, false/nil when not applicable):
+--   type         string   — type tag for tooling ("number"|"string"|"boolean"|
+--                                    "table"|"function"|"color"|"any")
+--   default      any|nil   — literal default value applied when prop is absent
+--   normalizer   fn|nil    — pure fn(value) -> value; transforms input before
+--                            storage (e.g. single-value padding -> 4-side table)
+--   validator    fn|nil    — pure fn(value) -> bool; returns false for invalid
+--                            input (Task 03 warns + falls back on false)
+--   isDimension  boolean   — true for width/height: setProperty routes these
+--                            through _resolveDimensionProperty (unit-string
+--                            resolution + border-box sync). Other unit-accepting
+--                            props (x/y/gap/padding/etc.) are resolved at
+--                            construction via special handlers, NOT via this flag.
+--   affectsLayout boolean  — true for props in the legacy setProperty
+--                            `layoutProperties` table; setting one invalidates
+--                            layout (matches baseline behavior exactly).
+--   syncsTheme   boolean   — true for props whose setProperty path must reach
+--                            ThemeManager/Renderer (disabled/active/themeComponent)
+--   hasDeferred  boolean   — true for callbacks that have an `on<Name>Deferred`
+--                            boolean companion prop (auto-wired by Task 03)
+--   storageKey   string|nil— when set, the prop is stored on the element under
+--                            this key instead of its own name (prop aliases, e.g.
+--                            isDisabled -> stored as `disabled`)
+
+local PropertySchema = {}
+
+---@type table<string, table>
+local registry = {}
+
+-- ---------------------------------------------------------------------------
+-- Pure normalizers (small + dependency-free; hot-pathed during construction)
+-- ---------------------------------------------------------------------------
+
+--- Expand a single value to a 4-side table. Leaves tables unchanged. nil passthrough.
+--- Used by padding/margin: `padding = 5` -> `{top=5,right=5,bottom=5,left=5}`.
+local function expandSides(value)
+  if value == nil then
+    return nil
+  end
+  if type(value) == "table" then
+    return value
+  end
+  return { top = value, right = value, bottom = value, left = value }
+end
+
+--- Normalize flex direction aliases to internal enum names.
+--- "row" -> "horizontal", "column" -> "vertical",
+--- "row-reverse" -> "horizontal-reverse", "column-reverse" -> "vertical-reverse";
+--- everything else passes through.
+local function normalizeFlexDirection(value)
+  if value == "row" then
+    return "horizontal"
+  elseif value == "column" then
+    return "vertical"
+  elseif value == "row-reverse" then
+    return "horizontal-reverse"
+  elseif value == "column-reverse" then
+    return "vertical-reverse"
+  end
+  return value
+end
+
+--- Replicate Element.new's border-shape normalization (pure).
+--- * table with sides: true -> 1, number -> value, false/nil -> false; nil if no
+---   truthy side remains.
+--- * number / other truthy scalar: kept as-is.
+--- * nil / false: nil.
+local function normalizeBorder(value)
+  if value == nil or value == false then
+    return nil
+  end
+  if type(value) == "table" then
+    local function side(v)
+      if v == true then
+        return 1
+      elseif type(v) == "number" then
+        return v
+      else
+        return false
+      end
+    end
+    local t = side(value.top)
+    local r = side(value.right)
+    local b = side(value.bottom)
+    local l = side(value.left)
+    if not (t or r or b or l) then
+      return nil
+    end
+    return { top = t, right = r, bottom = b, left = l }
+  end
+  return value
+end
+
+--- Replicate Element.new's cornerRadius-shape normalization (pure).
+--- * number: 0 -> nil, else the number.
+--- * table: nil if all four sides are zero/absent, else fill zeros for absent sides.
+--- * nil -> nil.
+local function normalizeCornerRadius(value)
+  if value == nil then
+    return nil
+  end
+  if type(value) == "number" then
+    if value == 0 then
+      return nil
+    end
+    return value
+  end
+  if type(value) == "table" then
+    -- Mirrors Element.new: `or` truthiness (0 is truthy in Lua). Only an all-
+    -- nil/false table collapses to nil; any present side — including 0 — yields
+    -- the 4-side table with zero-filled absent sides.
+    local hasAny = value.topLeft or value.topRight or value.bottomLeft or value.bottomRight
+    if not hasAny then
+      return nil
+    end
+    return {
+      topLeft = value.topLeft or 0,
+      topRight = value.topRight or 0,
+      bottomLeft = value.bottomLeft or 0,
+      bottomRight = value.bottomRight or 0,
+    }
+  end
+  return value
+end
+
+-- ---------------------------------------------------------------------------
+-- Pure validators (dependency-free; return boolean)
+-- ---------------------------------------------------------------------------
+
+--- Range validator factory: returns fn(v) -> bool. nil is treated as valid
+--- (absence handling is the default mechanism's job).
+local function rangeValidator(min, max)
+  return function(v)
+    if v == nil then
+      return true
+    end
+    return type(v) == "number" and v >= min and v <= max
+  end
+end
+
+--- Enum validator factory: returns fn(v) -> bool for membership in `set` (set may
+--- be an array or a map of value->truthy).
+local function enumValidator(set)
+  local lookup = {}
+  if type(set) == "table" then
+    for k, v in pairs(set) do
+      if type(k) == "number" then
+        lookup[v] = true
+      else
+        lookup[k] = true
+      end
+    end
+  end
+  return function(v)
+    if v == nil then
+      return true
+    end
+    return lookup[v] == true
+  end
+end
+
+--- Boolean validator: nil is valid (absence); otherwise must be a boolean.
+local function booleanValidator(v)
+  return v == nil or type(v) == "boolean"
+end
+
+-- ---------------------------------------------------------------------------
+-- Registry construction
+-- ---------------------------------------------------------------------------
+
+--- Build a fully-populated metadata entry, filling omitted fields with defaults.
+local function entry(spec)
+  return {
+    type = spec.type or "any",
+    default = spec.default,
+    normalizer = spec.normalizer,
+    validator = spec.validator,
+    isDimension = spec.isDimension == true,
+    affectsLayout = spec.affectsLayout == true,
+    syncsTheme = spec.syncsTheme == true,
+    hasDeferred = spec.hasDeferred == true,
+    storageKey = spec.storageKey,
+  }
+end
+
+--- Merge prop specs into the registry (additive; later entries override earlier).
+---@param specs table<string, table> map of prop-name -> spec
+---@return table registry the live registry table (for chaining/inspection)
+function PropertySchema.define(specs)
+  for name, spec in pairs(specs) do
+    registry[name] = entry(spec)
+  end
+  return registry
+end
+
+--- O(1) metadata lookup.
+---@param name string prop name
+---@return table|nil metadata nil for unknown props (no error)
+function PropertySchema.get(name)
+  return registry[name]
+end
+
+--- Return the live registry (for inspection / coverage assertions only — not for
+--- per-call construction).
+---@return table
+function PropertySchema.all()
+  return registry
+end
+
+--- True if a prop is registered.
+---@param name string
+---@return boolean
+function PropertySchema.has(name)
+  return registry[name] ~= nil
+end
+
+--- True if setting this prop invalidates layout (legacy `layoutProperties` set).
+--- O(1) registry lookup — no per-call table construction. Unknown props return false,
+--- matching the legacy `layoutProperties[name]` nil-lookup behavior exactly.
+---@param name string prop name
+---@return boolean
+function PropertySchema.affectsLayout(name)
+  local meta = registry[name]
+  return meta ~= nil and meta.affectsLayout == true
+end
+
+--- True for dimension props (width/height) that `setProperty` routes through
+--- `_resolveDimensionProperty` (unit-string resolution + border-box sync).
+--- O(1) registry lookup — no per-call table construction. Unknown props return false,
+--- matching the legacy `dimensionProperties[name]` nil-lookup behavior exactly.
+---@param name string prop name
+---@return boolean
+function PropertySchema.isDimension(name)
+  local meta = registry[name]
+  return meta ~= nil and meta.isDimension == true
+end
+
+--- True for props whose setProperty path must reach ThemeManager/Renderer
+--- (disabled/active/themeComponent). O(1) registry lookup — no per-call table
+--- construction. Unknown props return false, matching a legacy nil-lookup exactly.
+---@param name string prop name
+---@return boolean
+function PropertySchema.syncsTheme(name)
+  local meta = registry[name]
+  return meta ~= nil and meta.syncsTheme == true
+end
+
+-- ---------------------------------------------------------------------------
+-- Default schema (covers every prop handled in Element.new lines 259-1909 and
+-- Element:setProperty lines 4291-4417 of the Task-01 baseline).
+-- ---------------------------------------------------------------------------
+local function defineDefaults()
+  PropertySchema.define({
+    -- ------------------------------------------------------------------ identity
+    id = { type = "string" },
+    userdata = { type = "any" },
+    parent = { type = "table", affectsLayout = true },
+    children = { type = "table" },
+
+    -- ------------------------------------------------------------------ callbacks
+    onEvent = { type = "function", hasDeferred = true },
+    onFocus = { type = "function", hasDeferred = true },
+    onBlur = { type = "function", hasDeferred = true },
+    onTextInput = { type = "function", hasDeferred = true },
+    onTextChange = { type = "function", hasDeferred = true },
+    onEnter = { type = "function", hasDeferred = true },
+    onCreate = { type = "function", hasDeferred = true },
+    onTouchEvent = { type = "function", hasDeferred = true },
+    onGesture = { type = "function", hasDeferred = true },
+    onImageLoad = { type = "function", hasDeferred = true },
+    onImageError = { type = "function", hasDeferred = true },
+
+    -- Deferred companion flags (stored directly; no further Deferred companion)
+    onEventDeferred = { type = "boolean", default = false },
+    onFocusDeferred = { type = "boolean", default = false },
+    onBlurDeferred = { type = "boolean", default = false },
+    onTextInputDeferred = { type = "boolean", default = false },
+    onTextChangeDeferred = { type = "boolean", default = false },
+    onEnterDeferred = { type = "boolean", default = false },
+    onCreateDeferred = { type = "boolean", default = false },
+    onTouchEventDeferred = { type = "boolean", default = false },
+    onGestureDeferred = { type = "boolean", default = false },
+    onImageLoadDeferred = { type = "boolean", default = false },
+    onImageErrorDeferred = { type = "boolean", default = false },
+
+    -- focus / touch behavior
+    dropFocusOnSelection = { type = "boolean" },
+    customDraw = { type = "function" },
+    touchEnabled = { type = "boolean", default = true },
+    multiTouchEnabled = { type = "boolean", default = false },
+
+    -- ------------------------------------------------------------------ theme
+    theme = { type = "table" },
+    themeComponent = { type = "string", syncsTheme = true },
+    disabled = { type = "boolean", default = false, syncsTheme = true },
+    isDisabled = {
+      type = "boolean",
+      default = false,
+      syncsTheme = true,
+      storageKey = "disabled",
+    },
+    active = { type = "boolean", default = false, syncsTheme = true },
+    disableHighlight = { type = "boolean" },
+    themeStateLock = { type = "boolean" },
+    themeComponentDisabledStates = { type = "table" },
+    scaleCorners = { type = "boolean" },
+    scalingAlgorithm = { type = "string" },
+    contentAutoSizingMultiplier = { type = "table" },
+    contentBlur = { type = "table" },
+    backdropBlur = { type = "table" },
+
+    -- ------------------------------------------------------------------ text editing
+    editable = { type = "boolean", default = false },
+    multiline = { type = "boolean", default = false },
+    passwordMode = { type = "boolean", default = false },
+    textWrap = { type = "string" }, -- default computed from multiline
+    maxLines = { type = "number" },
+    maxLength = { type = "number" },
+    placeholder = { type = "string" },
+    inputType = { type = "string", default = "text" },
+    textOverflow = { type = "string", default = "clip" },
+    scrollable = { type = "boolean" }, -- default = multiline
+    autoGrow = { type = "boolean" }, -- default = multiline
+    selectOnFocus = { type = "boolean", default = false },
+    cursorColor = { type = "color" },
+    selectionColor = { type = "color" },
+    cursorBlinkRate = { type = "number", default = 0.5 },
+    text = { type = "string" },
+    textAlign = {
+      type = "string",
+      default = "start",
+      validator = enumValidator({ "start", "center", "end", "justify" }),
+    },
+    -- textAlignVertical is a derived storage field split out from textAlign
+    -- (bindVisualState resolves table/compound-string input into H + V). Its
+    -- validator is exposed for bindVisualState to validate the V component; the
+    -- prop itself stays in SPECIAL_PROPS because compound parsing needs
+    -- ErrorHandler warnings (schema is pure-Lua, cannot warn).
+    textAlignVertical = {
+      type = "string",
+      default = "start",
+      validator = enumValidator({ "start", "center", "end" }),
+    },
+    textColor = { type = "color" },
+    fontFamily = { type = "string" },
+    textSize = { type = "any" }, -- number | preset string; resolved by special handler
+    minTextSize = { type = "number" },
+    maxTextSize = { type = "number" },
+    autoScaleText = { type = "boolean", default = true },
+
+    -- ------------------------------------------------------------------ dimensions / box model
+    width = { type = "any", isDimension = true, affectsLayout = true },
+    height = { type = "any", isDimension = true, affectsLayout = true },
+    x = { type = "any", affectsLayout = false },
+    y = { type = "any", affectsLayout = false },
+    minWidth = { type = "any" },
+    maxWidth = { type = "any" },
+    minHeight = { type = "any" },
+    maxHeight = { type = "any" },
+    gap = { type = "any", affectsLayout = true },
+    padding = {
+      type = "any",
+      affectsLayout = true,
+      normalizer = expandSides,
+    },
+    margin = {
+      type = "any",
+      affectsLayout = true,
+      normalizer = expandSides,
+    },
+    flexDirection = {
+      type = "string",
+      default = "horizontal",
+      affectsLayout = true,
+      normalizer = normalizeFlexDirection,
+    },
+    flexWrap = { type = "string", default = "nowrap", affectsLayout = true },
+    justifyContent = { type = "string", default = "flex-start", affectsLayout = true },
+    alignItems = { type = "string", default = "stretch", affectsLayout = true },
+    alignContent = { type = "string", default = "stretch", affectsLayout = true },
+    positioning = { type = "string", default = "relative", affectsLayout = true },
+    gridRows = { type = "number", affectsLayout = true },
+    gridColumns = { type = "number", affectsLayout = true },
+    top = { type = "any", affectsLayout = true },
+    right = { type = "any", affectsLayout = true },
+    bottom = { type = "any", affectsLayout = true },
+    left = { type = "any", affectsLayout = true },
+    columnGap = { type = "any" },
+    rowGap = { type = "any" },
+    flex = { type = "any" }, -- shorthand: expands to flexGrow/flexShrink/flexBasis
+    flexGrow = { type = "number", default = 0, validator = rangeValidator(0, math.huge) },
+    flexShrink = { type = "number", default = 1, validator = rangeValidator(0, math.huge) },
+    flexBasis = { type = "any", default = "auto" },
+    alignSelf = { type = "string", default = "auto" },
+    justifySelf = { type = "string" },
+    z = { type = "number", default = 0 },
+    tabIndex = { type = "number" },
+
+    -- ------------------------------------------------------------------ border / background / visual
+    border = { type = "any", normalizer = normalizeBorder },
+    borderColor = { type = "color" }, -- default Color.new(0,0,0,1) via special handler
+    backgroundColor = { type = "color" }, -- default transparent via special handler
+    opacity = {
+      type = "number",
+      default = 1,
+      validator = rangeValidator(0, 1),
+    },
+    visibility = { type = "string", default = "visible" },
+    display = {
+      type = "boolean",
+      default = true,
+      validator = booleanValidator,
+    },
+    transform = { type = "table" },
+    cornerRadius = { type = "any", normalizer = normalizeCornerRadius },
+
+    -- ------------------------------------------------------------------ image
+    imagePath = { type = "string" },
+    image = { type = "table" },
+    objectFit = {
+      type = "string",
+      default = "fill",
+      validator = enumValidator({ "fill", "contain", "cover", "scale-down", "none" }),
+    },
+    objectPosition = { type = "string", default = "center center" },
+    imageOpacity = {
+      type = "number",
+      default = 1,
+      validator = rangeValidator(0, 1),
+    },
+    imageRepeat = {
+      type = "string",
+      default = "no-repeat",
+      validator = enumValidator({
+        "no-repeat",
+        "repeat",
+        "repeat-x",
+        "repeat-y",
+        "space",
+        "round",
+      }),
+    },
+    imageTint = { type = "color" },
+
+    -- ------------------------------------------------------------------ scroll / scrollbar
+    overflow = { type = "string" },
+    overflowX = { type = "string" },
+    overflowY = { type = "string" },
+    scrollbarWidth = { type = "number" },
+    scrollbarColor = { type = "color" },
+    scrollbarTrackColor = { type = "color" },
+    scrollbarRadius = { type = "number" },
+    scrollbarPadding = { type = "number" },
+    scrollSpeed = { type = "number" },
+    invertScroll = { type = "boolean" },
+    smoothScrollEnabled = { type = "boolean" },
+    scrollBarStyle = { type = "string" },
+    scrollbarKnobOffset = { type = "number" },
+    hideScrollbars = { type = "boolean" },
+    scrollbarPlacement = { type = "string" },
+    scrollbarBalance = { type = "number" },
+    _scrollX = { type = "number", storageKey = "_scrollX" },
+    _scrollY = { type = "number", storageKey = "_scrollY" },
+
+    -- ------------------------------------------------------------------ select
+    selectParent = { type = "table" },
+    selectOption = { type = "table" },
+
+    -- ------------------------------------------------------------------ transition
+    transition = { type = "table", default = {} },
+  })
+end
+
+--- (Re)populate the default schema. Idempotent: safe to call from Element.init
+--- for build profiles that re-require the module. Returns the live registry.
+---@return table registry
+function PropertySchema.populate()
+  defineDefaults()
+  return registry
+end
+
+-- Auto-populate on require so the registry is ready without an explicit init call
+-- (pure module, no external deps — safe at load time).
+PropertySchema.populate()
+
+return PropertySchema

libs/flexlove/modules/RoundedRect.lua

@@ -0,0 +1,124 @@
+local RoundedRect = {}
+
+--- Generate points for a rounded rectangle
+---@param x number
+---@param y number
+---@param width number
+---@param height number
+---@param cornerRadius {topLeft:number, topRight:number, bottomLeft:number, bottomRight:number}|number
+---@param segments number? -- Number of segments per corner arc (default: 10)
+---@return table -- Array of vertices for love.graphics.polygon
+function RoundedRect.getPoints(x, y, width, height, cornerRadius, segments)
+  segments = segments or 10
+  local points = {}
+
+  -- Helper to add arc points
+  local function addArc(cx, cy, radius, startAngle, endAngle)
+    if radius <= 0 then
+      table.insert(points, cx)
+      table.insert(points, cy)
+      return
+    end
+
+    for i = 0, segments do
+      local angle = startAngle + (endAngle - startAngle) * (i / segments)
+      table.insert(points, cx + math.cos(angle) * radius)
+      table.insert(points, cy + math.sin(angle) * radius)
+    end
+  end
+
+  -- Handle uniform corner radius (number)
+  if type(cornerRadius) == "number" then
+    cornerRadius = {
+      topLeft = cornerRadius,
+      topRight = cornerRadius,
+      bottomLeft = cornerRadius,
+      bottomRight = cornerRadius,
+    }
+  end
+
+  local r1 = math.min(cornerRadius.topLeft, width / 2, height / 2)
+  local r2 = math.min(cornerRadius.topRight, width / 2, height / 2)
+  local r3 = math.min(cornerRadius.bottomRight, width / 2, height / 2)
+  local r4 = math.min(cornerRadius.bottomLeft, width / 2, height / 2)
+
+  -- Top-right corner
+  addArc(x + width - r2, y + r2, r2, -math.pi / 2, 0)
+
+  -- Bottom-right corner
+  addArc(x + width - r3, y + height - r3, r3, 0, math.pi / 2)
+
+  -- Bottom-left corner
+  addArc(x + r4, y + height - r4, r4, math.pi / 2, math.pi)
+
+  -- Top-left corner
+  addArc(x + r1, y + r1, r1, math.pi, math.pi * 1.5)
+
+  return points
+end
+
+--- Draw a filled rounded rectangle
+---@param mode string -- "fill" or "line"
+---@param x number
+---@param y number
+---@param width number
+---@param height number
+---@param cornerRadius {topLeft:number, topRight:number, bottomLeft:number, bottomRight:number}|number|nil
+function RoundedRect.draw(mode, x, y, width, height, cornerRadius)
+  -- OPTIMIZATION: Handle nil cornerRadius (no rounding)
+  if not cornerRadius then
+    love.graphics.rectangle(mode, x, y, width, height)
+    return
+  end
+
+  -- Handle uniform corner radius (number)
+  if type(cornerRadius) == "number" then
+    if cornerRadius <= 0 then
+      love.graphics.rectangle(mode, x, y, width, height)
+      return
+    end
+    -- Convert to table format for processing
+    cornerRadius = {
+      topLeft = cornerRadius,
+      topRight = cornerRadius,
+      bottomLeft = cornerRadius,
+      bottomRight = cornerRadius,
+    }
+  end
+
+  -- Check if any corners are rounded
+  local hasRoundedCorners = cornerRadius.topLeft > 0
+    or cornerRadius.topRight > 0
+    or cornerRadius.bottomLeft > 0
+    or cornerRadius.bottomRight > 0
+
+  if not hasRoundedCorners then
+    -- No rounded corners, use regular rectangle
+    love.graphics.rectangle(mode, x, y, width, height)
+    return
+  end
+
+  local points = RoundedRect.getPoints(x, y, width, height, cornerRadius)
+
+  if mode == "fill" then
+    love.graphics.polygon("fill", points)
+  else
+    -- For line mode, draw the outline
+    love.graphics.polygon("line", points)
+  end
+end
+
+--- Create a stencil function for rounded rectangle clipping
+---@param x number
+---@param y number
+---@param width number
+---@param height number
+---@param cornerRadius {topLeft:number, topRight:number, bottomLeft:number, bottomRight:number}|number|nil
+---@return function
+function RoundedRect.stencilFunction(x, y, width, height, cornerRadius)
+  return function()
+    RoundedRect.draw("fill", x, y, width, height, cornerRadius)
+  end
+end
+
+return RoundedRect

libs/flexlove/modules/Select.lua

@@ -0,0 +1,719 @@
+---@class Select
+local Select = {}
+
+---Initialize Select module with required dependencies
+---@param deps table
+function Select.init(deps)
+  Select._ErrorHandler = deps.ErrorHandler
+  Select._Context = deps.Context
+  Select._StateManager = deps.StateManager
+  Select._utils = deps.utils
+  Select._Element = deps.Element
+end
+
+---Initialize selectParent state on an element
+---@param element Element
+---@param selectParentConfig table
+function Select.initSelectParent(element, selectParentConfig)
+  element._selectState = {
+    value = selectParentConfig.value,
+    open = selectParentConfig.open or false,
+    placeholder = selectParentConfig.placeholder,
+    selectFrame = nil,
+    selectAnchor = nil,
+    onChange = selectParentConfig.onChange,
+    options = {},
+    optionLookup = {},
+    expectedFrameParent = nil,
+    frameAdopted = false,
+  }
+
+  -- Restore select state from StateManager. Mode-aware via
+  -- Context.isImmediateMode (behavior-mode-unification task 11).
+  if Select._Context.isImmediateMode() and element._stateId and element._stateId ~= "" then
+    local state = Select._StateManager.getState(element._stateId)
+    if state and state._selectOpen ~= nil then
+      element._selectState.open = state._selectOpen
+    end
+    if state and state._selectValue ~= nil then
+      element._selectState.value = state._selectValue
+      if element.selectParent then
+        element.selectParent.value = state._selectValue
+      end
+    end
+    if state and state._selectSelectedLabel ~= nil then
+      element._selectState.selectedLabel = state._selectSelectedLabel
+    end
+  end
+end
+
+---Initialize selectOption on an element
+---@param element Element
+---@param selectOptionConfig table
+function Select.initSelectOption(element, selectOptionConfig)
+  element.selectOption = {
+    value = selectOptionConfig.value,
+    label = selectOptionConfig.label or element.text,
+    disabled = selectOptionConfig.disabled or false,
+  }
+end
+
+---@param selectParent Element
+function Select.rebuildOptionLookup(selectParent)
+  if not selectParent or not selectParent._selectState then
+    return
+  end
+
+  selectParent._selectState.optionLookup = {}
+  for _, optionElement in ipairs(selectParent._selectState.options) do
+    if optionElement and optionElement.selectOption then
+      selectParent._selectState.optionLookup[optionElement.selectOption.value] = optionElement
+    end
+  end
+end
+
+---@param selectParent Element
+function Select.syncOptionStates(selectParent)
+  if not selectParent or not selectParent._selectState then
+    return
+  end
+
+  local selectedOption = nil
+  local selectedLabel = selectParent._selectState.selectedLabel
+
+  for _, optionElement in ipairs(selectParent._selectState.options) do
+    local isSelected = optionElement.selectOption
+      and optionElement.selectOption.value == selectParent._selectState.value
+    optionElement._selectSelected = isSelected
+    optionElement.ariaChecked = isSelected
+
+    if isSelected then
+      selectedOption = optionElement
+      selectedLabel = optionElement.selectOption.label or optionElement.text
+    end
+  end
+
+  selectParent._selectState.selectedOption = selectedOption
+  selectParent._selectState.selectedLabel = selectedLabel
+end
+
+---@param element Element
+function Select.resetOptions(element)
+  if not element._selectState then
+    return
+  end
+
+  element._selectState.options = {}
+  element._selectState.optionLookup = {}
+  element._selectState.selectedOption = nil
+end
+
+---@param frame any
+---@return boolean
+function Select.isValidSelectFrame(frame)
+  local Element = Select._Element
+  return type(frame) == "table" and getmetatable(frame) == Element
+end
+
+---@param element Element
+---@param code string
+---@param details table?
+function Select.warnSelectFrame(element, code, details)
+  Select._ErrorHandler:warn("Element", code, details or { element = element.id })
+end
+
+---@param element Element
+---@param frame Element
+function Select.trackManagedFrame(element, frame)
+  element._selectState.selectFrame = frame
+  local expectedParent = element._selectState.selectAnchor or element
+  element._selectState.expectedFrameParent = expectedParent
+  element._selectState.frameAdopted = frame.parent == expectedParent
+  if frame._managedSelectBaseOpacity == nil then
+    frame._managedSelectBaseOpacity = frame.opacity
+  end
+  if frame._managedSelectBaseVisibility == nil then
+    frame._managedSelectBaseVisibility = frame.visibility or "visible"
+  end
+  if frame._managedSelectBaseDisabled == nil then
+    frame._managedSelectBaseDisabled = frame.disabled or false
+  end
+  frame._managedSelectOwner = element
+  frame._managedSelectFrame = true
+end
+
+---@param element Element
+---@return Element
+function Select.getOrCreateManagedAnchor(element)
+  if element._selectState.selectAnchor then
+    return element._selectState.selectAnchor
+  end
+
+  local Element = Select._Element
+  local anchor = Element.new({
+    id = string.format("%s__select_anchor", element.id or "select"),
+    parent = element,
+    positioning = Select._utils.enums.Positioning.ABSOLUTE,
+    left = 0,
+    top = element:getBorderBoxHeight(),
+    width = element:getBorderBoxWidth(),
+    opacity = 1,
+    visibility = "hidden",
+    disabled = true,
+  })
+
+  anchor._managedSelectAnchor = true
+  anchor._managedSelectOwner = element
+  element._selectState.selectAnchor = anchor
+  return anchor
+end
+
+---@param element Element
+---@param frame Element
+function Select.applyManagedFrameLayout(element, frame)
+  local anchor = Select.getOrCreateManagedAnchor(element)
+  local triggerBorderBoxWidth = element:getBorderBoxWidth()
+  anchor.left = 0
+  anchor.top = element:getBorderBoxHeight()
+  anchor.width = triggerBorderBoxWidth
+  anchor.units.left = { value = 0, unit = "px" }
+  anchor.units.top = { value = element:getBorderBoxHeight(), unit = "px" }
+  anchor.units.width = { value = triggerBorderBoxWidth, unit = "px" }
+  frame._managedSelectMinimumBorderBoxWidth = triggerBorderBoxWidth
+
+  frame.positioning = frame.positioning or Select._utils.enums.Positioning.RELATIVE
+  frame._explicitlyAbsolute = false
+  frame.left = nil
+  frame.top = nil
+  frame.right = nil
+  frame.bottom = nil
+
+  if frame.parent ~= anchor then
+    frame:setParent(anchor)
+  end
+
+  if frame.autosizing and frame.autosizing.width then
+    local contentWidth = frame:calculateAutoWidth()
+    frame._borderBoxWidth = contentWidth + frame.padding.left + frame.padding.right
+    frame.width = contentWidth
+  end
+
+  if frame.parent == anchor then
+    anchor.width = math.max(triggerBorderBoxWidth, frame:getBorderBoxWidth())
+    anchor.units.width = { value = anchor.width, unit = "px" }
+  end
+
+  element._selectState.expectedFrameParent = anchor
+  element._selectState.frameAdopted = frame.parent == anchor
+end
+
+---@param element Element
+---@param frame Element
+function Select.adoptSelectFrame(element, frame)
+  if not element._selectState then
+    return
+  end
+
+  if not Select.isValidSelectFrame(frame) then
+    Select.warnSelectFrame(element, "ELEM_007", {
+      element = element.id,
+      property = "selectParent.selectFrame",
+      got = type(frame),
+    })
+    return
+  end
+
+  if frame == element then
+    Select.warnSelectFrame(element, "ELEM_007", {
+      element = element.id,
+      property = "selectParent.selectFrame",
+      reason = "select cannot use itself as its managed frame",
+    })
+    return
+  end
+
+  local anchor = Select.getOrCreateManagedAnchor(element)
+
+  if frame.parent and frame.parent ~= element and frame.parent ~= anchor then
+    Select.warnSelectFrame(element, "ELEM_008", {
+      element = element.id,
+      frame = frame.id,
+      parent = frame.parent.id,
+    })
+  end
+
+  Select.trackManagedFrame(element, frame)
+  Select.applyManagedFrameLayout(element, frame)
+  Select.syncManagedFrameVisibility(element)
+
+  -- Layout is deferred to endFrame in immediate mode. shouldLayout()
+  -- encapsulates the mode check (behavior-mode-unification task 11).
+  if Select._StateManager.shouldLayout() then
+    anchor:layoutChildren()
+    element:layoutChildren()
+  end
+
+  local pendingOptions = {}
+  for _, child in ipairs(element.children) do
+    if child ~= frame and child.selectOption then
+      table.insert(pendingOptions, child)
+    end
+  end
+
+  for _, option in ipairs(pendingOptions) do
+    Select.attachOptionToManagedFrame(option)
+  end
+end
+
+---@param element Element
+function Select.ensureFrameState(element)
+  if not element._selectState or not element._selectState.selectFrame then
+    return
+  end
+
+  local frame = element._selectState.selectFrame
+  local anchor = element._selectState.selectAnchor
+  if anchor then
+    local triggerBorderBoxWidth = element:getBorderBoxWidth()
+    anchor.left = 0
+    anchor.top = element:getBorderBoxHeight()
+    anchor.width = triggerBorderBoxWidth
+    anchor.units.left = { value = 0, unit = "px" }
+    anchor.units.top = { value = element:getBorderBoxHeight(), unit = "px" }
+    anchor.units.width = { value = triggerBorderBoxWidth, unit = "px" }
+    frame._managedSelectMinimumBorderBoxWidth = triggerBorderBoxWidth
+    if frame.autosizing and frame.autosizing.width then
+      local contentWidth = frame:calculateAutoWidth()
+      frame._borderBoxWidth = contentWidth + frame.padding.left + frame.padding.right
+      frame.width = contentWidth
+    end
+    if frame.parent == anchor then
+      anchor.width = math.max(triggerBorderBoxWidth, frame:getBorderBoxWidth())
+      anchor.units.width = { value = anchor.width, unit = "px" }
+    end
+    if frame.parent == anchor then
+      anchor:layoutChildren()
+    end
+  elseif frame.parent == element then
+    Select.applyManagedFrameLayout(element, frame)
+  end
+
+  local expectedParent = anchor or element._selectState.expectedFrameParent
+  if frame.parent ~= expectedParent then
+    Select.warnSelectFrame(element, "ELEM_009", {
+      element = element.id,
+      frame = frame.id,
+      expectedParent = expectedParent and expectedParent.id or nil,
+      actualParent = frame.parent and frame.parent.id or nil,
+    })
+    element._selectState.expectedFrameParent = frame.parent
+    element._selectState.frameAdopted = frame.parent == expectedParent
+  end
+end
+
+---@param element Element
+function Select.syncManagedFrameVisibility(element)
+  if not element._selectState or not element._selectState.selectFrame then
+    return
+  end
+
+  local frame = element._selectState.selectFrame
+  local anchor = element._selectState.selectAnchor
+  local isOpen = element._selectState.open == true
+  frame.visibility = isOpen and (frame._managedSelectBaseVisibility or "visible") or "hidden"
+  frame.opacity = frame._managedSelectBaseOpacity or 1
+  if isOpen then
+    frame.disabled = frame._managedSelectBaseDisabled == true
+  else
+    frame.disabled = true
+  end
+  if anchor then
+    anchor.visibility = isOpen and "visible" or "hidden"
+    anchor.opacity = 1
+    anchor.disabled = not isOpen
+  end
+end
+
+---@param element Element
+---@return Element?
+function Select.findOwningSelectParent(element)
+  if element._selectParentHint and element._selectParentHint._selectState then
+    return element._selectParentHint
+  end
+
+  local current = element.parent
+  while current do
+    if current._selectState then
+      return current
+    end
+    current = current.parent
+  end
+
+  return nil
+end
+
+---@param element Element
+function Select.registerWithSelectParent(element)
+  if not element.selectOption then
+    return
+  end
+
+  local selectParent = Select.findOwningSelectParent(element)
+  if not selectParent then
+    return
+  end
+
+  element._selectParentElement = selectParent
+
+  for _, optionElement in ipairs(selectParent._selectState.options) do
+    if optionElement == element then
+      return
+    end
+  end
+
+  table.insert(selectParent._selectState.options, element)
+  Select.rebuildOptionLookup(selectParent)
+  Select.syncOptionStates(selectParent)
+end
+
+---@param element Element
+function Select.attachOptionToManagedFrame(element)
+  if not element.selectOption then
+    return
+  end
+
+  local selectParent = Select.findOwningSelectParent(element)
+  if not selectParent or not selectParent._selectState or not selectParent._selectState.selectFrame then
+    return
+  end
+
+  local selectFrame = selectParent._selectState.selectFrame
+  if element.parent ~= selectFrame then
+    element._selectParentHint = selectParent
+
+    if
+      element._originalPositioning == Select._utils.enums.Positioning.ABSOLUTE
+      and element._managedSelectOptionUsesFrameLayout == nil
+    then
+      element._managedSelectOptionUsesFrameLayout = true
+      element.positioning = Select._utils.enums.Positioning.RELATIVE
+      element._originalPositioning = nil
+      element._explicitlyAbsolute = false
+      element.left = nil
+      element.top = nil
+      element.right = nil
+      element.bottom = nil
+    end
+
+    element:setParent(selectFrame)
+    -- Ensure frame geometry eagerly only in retained mode; deferred to the
+    -- per-frame update in immediate mode (behavior-mode-unification task 11).
+    if Select._StateManager.shouldLayout() then
+      Select.ensureFrameState(selectParent)
+    end
+  end
+end
+
+---@param element Element
+function Select.unregisterFromSelectParent(element)
+  if not element.selectOption or not element._selectParentElement or not element._selectParentElement._selectState then
+    element._selectParentElement = nil
+    return
+  end
+
+  local selectParent = element._selectParentElement
+  for index, optionElement in ipairs(selectParent._selectState.options) do
+    if optionElement == element then
+      table.remove(selectParent._selectState.options, index)
+      break
+    end
+  end
+
+  Select.rebuildOptionLookup(selectParent)
+  Select.syncOptionStates(selectParent)
+  element._selectParentElement = nil
+end
+
+---@param element Element
+function Select.saveStateToStateManager(element)
+  if not element._selectState then
+    return
+  end
+  if element._stateId and Select._Context.isImmediateMode() and element._stateId ~= "" then
+    Select._StateManager.updateState(element._stateId, {
+      _selectOpen = element._selectState.open,
+      _selectValue = element._selectState.value,
+      _selectSelectedLabel = element._selectState.selectedLabel,
+    })
+  end
+end
+
+---@param element Element
+function Select.openSelect(element)
+  if not element._selectState then
+    return
+  end
+
+  Select.ensureFrameState(element)
+  element._selectState.open = true
+  element.ariaExpanded = true
+  if element.selectParent then
+    element.selectParent.open = true
+  end
+  Select.syncManagedFrameVisibility(element)
+  Select.saveStateToStateManager(element)
+end
+
+---@param element Element
+function Select.closeSelect(element)
+  if not element._selectState then
+    return
+  end
+
+  Select.ensureFrameState(element)
+  element._selectState.open = false
+  element.ariaExpanded = false
+  if element.selectParent then
+    element.selectParent.open = false
+  end
+  Select.syncManagedFrameVisibility(element)
+  Select.saveStateToStateManager(element)
+end
+
+---@param element Element
+function Select.toggleSelect(element)
+  if not element._selectState then
+    return
+  end
+
+  if element.disabled then
+    return
+  end
+
+  if element._selectState.open then
+    Select.closeSelect(element)
+  else
+    Select.openSelect(element)
+  end
+
+  if element.onEvent then
+    element.onEvent(element, { type = "selecttoggle", open = element._selectState.open })
+  end
+end
+
+---@param element Element
+---@return boolean
+function Select.isSelectOpen(element)
+  return element._selectState ~= nil and element._selectState.open == true
+end
+
+---@param element Element
+---@return any
+function Select.getSelectValue(element)
+  if not element._selectState then
+    return nil
+  end
+  return element._selectState.value
+end
+
+---@param element Element
+---@return string?
+function Select.getSelectLabel(element)
+  if not element._selectState then
+    return nil
+  end
+
+  local selectedOption = element._selectState.selectedOption
+    or element._selectState.optionLookup[element._selectState.value]
+  if selectedOption and selectedOption.selectOption then
+    return selectedOption.selectOption.label or selectedOption.text
+  end
+
+  return element._selectState.selectedLabel or element._selectState.placeholder
+end
+
+---@param element Element
+---@return boolean
+function Select.isSelectedOption(element)
+  if not element.selectOption or not element._selectParentElement or not element._selectParentElement._selectState then
+    return false
+  end
+  return element._selectParentElement._selectState.value == element.selectOption.value
+end
+
+---@param element Element
+---@param value any
+---@param optionElement Element?
+function Select.setSelectValue(element, value, optionElement)
+  if not element._selectState then
+    return
+  end
+
+  if element.disabled then
+    return
+  end
+
+  local didChange = element._selectState.value ~= value
+  element._selectState.value = value
+  if element.selectParent then
+    element.selectParent.value = value
+  end
+
+  if optionElement and optionElement.selectOption then
+    element._selectState.selectedLabel = optionElement.selectOption.label or optionElement.text
+  end
+
+  Select.syncOptionStates(element)
+  Select.closeSelect(element)
+  Select.saveStateToStateManager(element)
+
+  if element.onEvent then
+    element.onEvent(element, { type = "selectchange", value = value, option = optionElement })
+  end
+
+  if didChange and element._selectState.onChange then
+    element._selectState.onChange(element, value, optionElement and optionElement.selectOption or nil)
+  end
+end
+
+---@param element Element
+function Select.handleRelease(element)
+  if element.disabled then
+    return
+  end
+
+  if element.selectOption then
+    local selectParent = element._selectParentElement or Select.findOwningSelectParent(element)
+    if not selectParent then
+      return
+    end
+
+    if element.selectOption.disabled then
+      Select.closeSelect(selectParent)
+      return
+    end
+
+    Select.setSelectValue(selectParent, element.selectOption.value, element)
+    return
+  end
+
+  if element._selectState then
+    Select.toggleSelect(element)
+  end
+end
+
+---Save select state for state persistence (called from Element:saveState)
+---@param element Element
+---@return table?
+function Select.saveState(element)
+  if not element._selectState then
+    return nil
+  end
+  return {
+    value = element._selectState.value,
+    open = element._selectState.open,
+    selectedLabel = element._selectState.selectedLabel,
+  }
+end
+
+---Restore select state (called from Element:restoreState)
+---@param element Element
+---@param state table
+function Select.restoreState(element, state)
+  if not element._selectState or not state then
+    return
+  end
+  element._selectState.value = state.value
+  element._selectState.open = state.open or false
+  element._selectState.selectedLabel = state.selectedLabel
+  if element.selectParent then
+    element.selectParent.value = state.value
+    element.selectParent.open = state.open or false
+  end
+  element.ariaExpanded = element._selectState.open
+  Select.syncOptionStates(element)
+end
+
+---Clean up select-related resources (called from Element:destroy)
+---@param element Element
+function Select.cleanupDestroy(element)
+  if element._selectState then
+    local frame = element._selectState.selectFrame
+    local anchor = element._selectState.selectAnchor
+    if frame then
+      frame._managedSelectOwner = nil
+      frame._managedSelectFrame = nil
+      frame._managedSelectBaseOpacity = nil
+      frame._managedSelectBaseVisibility = nil
+      frame._managedSelectBaseDisabled = nil
+    end
+    if anchor then
+      anchor._managedSelectOwner = nil
+      anchor._managedSelectAnchor = nil
+    end
+    element._selectState = nil
+  end
+  if element._managedSelectFrame and element._managedSelectOwner then
+    if element._managedSelectOwner._selectState then
+      element._managedSelectOwner._selectState.selectFrame = nil
+      element._managedSelectOwner._selectState.expectedFrameParent = nil
+      element._managedSelectOwner._selectState.frameAdopted = false
+    end
+    element._managedSelectOwner = nil
+    element._managedSelectFrame = nil
+    element._managedSelectBaseOpacity = nil
+    element._managedSelectBaseVisibility = nil
+    element._managedSelectBaseDisabled = nil
+  end
+  if element._managedSelectAnchor and element._managedSelectOwner then
+    if element._managedSelectOwner._selectState then
+      element._managedSelectOwner._selectState.selectAnchor = nil
+    end
+    element._managedSelectOwner = nil
+    element._managedSelectAnchor = nil
+  end
+  if element.selectParent then
+    element.selectParent.onChange = nil
+  end
+end
+
+--- Called when a select parent removes a child: clears frame/anchor refs if the removed child was the
+--- select-managed frame or anchor. Keeps select state-mutation logic owned by the Select module.
+---@param element Element The select parent whose child was removed.
+---@param child Element The removed child.
+function Select.handleChildRemoved(element, child)
+  if not element._selectState then
+    return
+  end
+  if element._selectState.selectFrame == child then
+    element._selectState.selectFrame = nil
+    element._selectState.expectedFrameParent = nil
+    element._selectState.frameAdopted = false
+  end
+  if element._selectState.selectAnchor == child then
+    element._selectState.selectAnchor = nil
+  end
+end
+
+--- Layout-path hook: adjust an auto-width child's border-box width for a managed-select frame.
+--- Invoked from LayoutEngine (via the Element delegate) during vertical-flex auto-width calculation.
+---@param element Element The managed-select frame (the dropdown container).
+---@param child Element The flex child being measured.
+---@param childBorderBoxWidth number Current computed border-box width of `child`.
+---@return number Possibly-adjusted border-box width.
+function Select.adjustAutoWidthChild(element, child, childBorderBoxWidth)
+  if
+    element._managedSelectFrame
+    and element.autosizing
+    and element.autosizing.width
+    and child.units
+    and child.units.width
+    and child.units.width.unit == "%"
+  then
+    local intrinsicBorderBoxWidth = child:calculateAutoWidth() + child.padding.left + child.padding.right
+    return math.max(childBorderBoxWidth, intrinsicBorderBoxWidth)
+  end
+  return childBorderBoxWidth
+end
+
+return Select

libs/flexlove/modules/StateManager.lua

@@ -0,0 +1,790 @@
+---@class StateManager
+local StateManager = {}
+
+-- ErrorHandler will be injected via init
+local ErrorHandler
+
+-- State storage: ID -> state table
+local stateStore = {}
+
+-- Frame tracking metadata: ID -> {lastFrame, createdFrame, accessCount}
+local stateMetadata = {}
+
+-- Frame counter
+local frameNumber = 0
+
+-- Counter to track multiple elements created at the same source location (e.g., in loops)
+local callSiteCounters = {}
+
+-- Stateful element mapping: stateId -> element instance
+-- Used in retained mode for cache-through: StateManager resolves id -> element -> field
+local statefulElements = {}
+
+-- Dirty state tracking for flushFrame: set of {id, key} pairs modified this frame
+local dirtyState = {}
+
+-- Immediate mode flag
+local _immediateMode = false
+
+-- Configuration
+local config = {
+  stateRetentionFrames = 2, -- Keep unused state for 2 frames
+  maxStateEntries = 1000, -- Maximum state entries before forced GC
+}
+
+-- Default state values (sparse storage - don't store these)
+local stateDefaults = {
+  -- Interaction states
+  hover = false,
+  pressed = false,
+  focused = false,
+  disabled = false,
+  active = false,
+
+  -- Scrollbar states
+  scrollbarHoveredVertical = false,
+  scrollbarHoveredHorizontal = false,
+  scrollbarDragging = false,
+  hoveredScrollbar = nil,
+  scrollbarDragOffset = 0,
+  dragStartMouseX = 0,
+  dragStartMouseY = 0,
+  dragStartScrollX = 0,
+  dragStartScrollY = 0,
+
+  -- Scroll position
+  scrollX = 0,
+  scrollY = 0,
+  _scrollX = 0,
+  _scrollY = 0,
+
+  -- Click tracking
+  _clickCount = 0,
+  _lastClickTime = nil,
+  _lastClickButton = nil,
+
+  -- Internal states
+  _hovered = nil,
+  _focused = nil,
+  _cursorPosition = nil,
+  _selectionStart = nil,
+  _selectionEnd = nil,
+  _textBuffer = "",
+  _cursorBlinkTimer = 0,
+  _cursorVisible = true,
+  _cursorBlinkPaused = false,
+  _cursorBlinkPauseTimer = 0,
+}
+
+--- Check if a value equals the default for a key
+---@param key string State key
+---@param value any Value to check
+---@return boolean isDefault True if value equals default
+local function isDefaultValue(key, value)
+  local defaultVal = stateDefaults[key]
+
+  -- If no default defined, check for common defaults
+  if defaultVal == nil then
+    -- Empty tables are default
+    if type(value) == "table" and next(value) == nil then
+      return true
+    end
+    -- nil values are default
+    if value == nil then
+      return true
+    end
+    -- Otherwise, not a default value
+    return false
+  end
+
+  -- Compare values
+  if type(value) == "table" then
+    -- Empty tables are considered default
+    if next(value) == nil then
+      return true
+    end
+    -- For other tables, compare contents (shallow)
+    if type(defaultVal) ~= "table" then
+      return false
+    end
+    for k, v in pairs(value) do
+      if defaultVal[k] ~= v then
+        return false
+      end
+    end
+    return true
+  else
+    return value == defaultVal
+  end
+end
+
+-- ====================
+-- ID Generation
+-- ====================
+
+--- Generate a hash from a table of properties
+---@param props table
+---@param visited table|nil Tracking table to prevent circular references
+---@param depth number|nil Current recursion depth
+---@return string
+local function hashProps(props, visited, depth)
+  if not props then
+    return ""
+  end
+
+  -- Initialize visited table on first call
+  visited = visited or {}
+  depth = depth or 0
+
+  -- Limit recursion depth to prevent deep nesting issues
+  if depth > 3 then
+    return "[deep]"
+  end
+
+  -- Check if we've already visited this table (circular reference)
+  if visited[props] then
+    return "[circular]"
+  end
+
+  -- Mark this table as visited
+  visited[props] = true
+
+  local parts = {}
+  local keys = {}
+
+  -- Properties to skip (they cause issues or aren't relevant for ID generation)
+  local skipKeys = {
+    onEvent = true,
+    parent = true,
+    children = true,
+    onFocus = true,
+    onBlur = true,
+    onTextInput = true,
+    onTextChange = true,
+    onEnter = true,
+    userdata = true,
+    -- Dynamic input/state properties that should not affect ID stability
+    text = true, -- Text content changes as user types
+    placeholder = true, -- Placeholder text is presentational
+    editable = true, -- Editable state can be toggled dynamically
+    selectOnFocus = true, -- Input behavior flag
+    autoGrow = true, -- Auto-grow behavior flag
+    passwordMode = true, -- Password mode can be toggled
+  }
+
+  -- Collect and sort keys for consistent ordering
+  for k in pairs(props) do
+    if not skipKeys[k] then
+      table.insert(keys, k)
+    end
+  end
+  table.sort(keys)
+
+  -- Build hash string from sorted key-value pairs
+  for _, k in ipairs(keys) do
+    local v = props[k]
+    local vtype = type(v)
+
+    if vtype == "string" or vtype == "number" or vtype == "boolean" then
+      table.insert(parts, k .. "=" .. tostring(v))
+    elseif vtype == "table" then
+      table.insert(parts, k .. "={" .. hashProps(v, visited, depth + 1) .. "}")
+    end
+  end
+
+  return table.concat(parts, ";")
+end
+
+--- Generate a unique ID from call site and properties
+---@param props table|nil Optional properties to include in ID generation
+---@param parent table|nil Optional parent element for tree-based ID generation
+---@return string
+function StateManager.generateID(props, parent)
+  -- Get call stack information
+  local info = debug.getinfo(3, "Sl") -- Level 3: caller of Element.new -> caller of generateID
+
+  if not info then
+    -- Fallback to random ID if debug info unavailable
+    return "auto_" .. tostring(math.random(1000000, 9999999))
+  end
+
+  local source = info.source or "unknown"
+  local line = info.currentline or 0
+
+  -- Create base location key from source file and line number
+  local filename = source:match("([^/\\]+)$") or source -- Get filename
+  filename = filename:gsub("%.lua$", "") -- Remove .lua extension
+  local locationKey = filename .. "_L" .. line
+
+  -- If we have a parent, use tree-based ID generation for stability
+  if parent and parent.id and parent.id ~= "" then
+    -- For child elements, use call-site (file + line) like top-level elements
+    -- This ensures the same call site always generates the same ID, even when
+    -- retained children persist in parent.children array
+    local baseID = parent.id .. "_" .. locationKey
+
+    -- Count how many children have been created at THIS call site
+    local callSiteKey = parent.id .. "_" .. locationKey
+    callSiteCounters[callSiteKey] = (callSiteCounters[callSiteKey] or 0) + 1
+    local instanceNum = callSiteCounters[callSiteKey]
+
+    if instanceNum > 1 then
+      baseID = baseID .. "_" .. instanceNum
+    end
+
+    -- Add property hash if provided (for additional differentiation)
+    if props then
+      local propHash = hashProps(props)
+      if propHash ~= "" then
+        -- Use first 8 chars of a simple hash
+        local hash = 0
+        for i = 1, #propHash do
+          hash = (hash * 31 + string.byte(propHash, i)) % 1000000
+        end
+        baseID = baseID .. "_" .. hash
+      end
+    end
+
+    return baseID
+  end
+
+  -- No parent (top-level element): use call-site counter approach
+  -- Track how many elements have been created at this location
+  callSiteCounters[locationKey] = (callSiteCounters[locationKey] or 0) + 1
+  local instanceNum = callSiteCounters[locationKey]
+
+  local baseID = locationKey
+
+  -- Add instance number if multiple elements created at same location (e.g., in loops)
+  if instanceNum > 1 then
+    baseID = baseID .. "_" .. instanceNum
+  end
+
+  -- Add property hash if provided (for additional differentiation)
+  if props then
+    local propHash = hashProps(props)
+    if propHash ~= "" then
+      -- Use first 8 chars of a simple hash
+      local hash = 0
+      for i = 1, #propHash do
+        hash = (hash * 31 + string.byte(propHash, i)) % 1000000
+      end
+      baseID = baseID .. "_" .. hash
+    end
+  end
+
+  return baseID
+end
+
+-- ====================
+-- State Management
+-- ====================
+
+--- Initialize StateManager with dependencies
+---@param deps table Dependencies: { ErrorHandler = ErrorHandler }
+function StateManager.init(deps)
+  if type(deps) == "table" then
+    ErrorHandler = deps.ErrorHandler
+  end
+end
+
+--- Get state for an element ID, creating if it doesn't exist
+---@param id string Element ID
+---@param defaultState table|nil Default state if creating new
+---@return table state State table for the element
+function StateManager.getState(id, defaultState)
+  if not id then
+    ErrorHandler:error("StateManager", "SYS_001", {
+      parameter = "id",
+      value = "nil",
+    })
+  end
+
+  -- Create state if it doesn't exist
+  if not stateStore[id] then
+    -- Start with empty state (sparse storage)
+    stateStore[id] = defaultState or {}
+
+    -- Create metadata
+    stateMetadata[id] = {
+      lastFrame = frameNumber,
+      createdFrame = frameNumber,
+      accessCount = 0,
+    }
+  else
+    -- Update metadata
+    local meta = stateMetadata[id]
+    meta.lastFrame = frameNumber
+    meta.accessCount = meta.accessCount + 1
+  end
+
+  return stateStore[id]
+end
+
+--- Set state for an element ID (replaces entire state)
+---@param id string Element ID
+---@param state table State to store
+function StateManager.setState(id, state)
+  if not id then
+    ErrorHandler:error("StateManager", "SYS_001", {
+      parameter = "id",
+      value = "nil",
+    })
+  end
+
+  -- Create sparse state (remove default values)
+  local sparseState = {}
+  for key, value in pairs(state) do
+    if not isDefaultValue(key, value) then
+      sparseState[key] = value
+    end
+  end
+
+  stateStore[id] = sparseState
+
+  -- Update or create metadata
+  if not stateMetadata[id] then
+    stateMetadata[id] = {
+      lastFrame = frameNumber,
+      createdFrame = frameNumber,
+      accessCount = 1,
+    }
+  else
+    stateMetadata[id].lastFrame = frameNumber
+  end
+end
+
+--- Update state for an element ID (merges with existing state)
+---@param id string Element ID
+---@param newState table New state values to merge
+function StateManager.updateState(id, newState)
+  local state = StateManager.getState(id)
+
+  -- Merge new state into existing state (with diffing optimization)
+  local changed = false
+  for key, value in pairs(newState) do
+    if state[key] ~= value then
+      state[key] = value
+      changed = true
+    end
+  end
+
+  -- Only update metadata if something actually changed
+  if changed then
+    stateMetadata[id].lastFrame = frameNumber
+  end
+end
+
+--- Update state only if values have changed (optimized for immediate mode)
+---@param id string Element ID
+---@param newState table New state values to merge
+---@return boolean changed True if any values changed
+function StateManager.updateStateIfChanged(id, newState)
+  local state = StateManager.getState(id)
+  local changed = false
+
+  for key, value in pairs(newState) do
+    -- Skip if value hasn't changed (optimization)
+    if state[key] ~= value then
+      state[key] = value
+      changed = true
+    end
+  end
+
+  if changed then
+    stateMetadata[id].lastFrame = frameNumber
+  end
+
+  return changed
+end
+
+--- Clear state for a specific element ID
+---@param id string Element ID
+function StateManager.clearState(id)
+  stateStore[id] = nil
+  stateMetadata[id] = nil
+end
+
+--- Mark state as used this frame (updates last accessed frame)
+---@param id string Element ID
+function StateManager.markStateUsed(id)
+  if stateMetadata[id] then
+    stateMetadata[id].lastFrame = frameNumber
+  end
+end
+
+-- ====================
+-- Frame Management
+-- ====================
+
+--- Increment frame counter (called at frame start)
+function StateManager.incrementFrame()
+  frameNumber = frameNumber + 1
+  -- Reset call site counters for new frame
+  callSiteCounters = {}
+end
+
+--- Get current frame number
+---@return number
+function StateManager.getFrameNumber()
+  return frameNumber
+end
+
+-- ====================
+-- Granular State Access (Unified API for both modes)
+-- ====================
+
+--- Get a single state value by key for a given element ID.
+--- Works identically in both modes — the caller does not need to know the mode.
+---
+--- Immediate mode: reads from persistent state store.
+--- Retained mode: resolves through registered element field (cache-through).
+---
+---@param id string Element state ID
+---@param key string State key
+---@return any value The stored value, or nil if not found
+function StateManager.getStateValue(id, key)
+  if not id or not key then
+    ErrorHandler:error("StateManager", "SYS_001", {
+      parameter = "id and key",
+      value = "missing",
+    })
+  end
+
+  -- Update metadata for access tracking
+  if stateMetadata[id] then
+    stateMetadata[id].lastFrame = frameNumber
+    stateMetadata[id].accessCount = stateMetadata[id].accessCount + 1
+  end
+
+  if _immediateMode then
+    -- Immediate mode: read from persistent state store
+    local state = stateStore[id]
+    if state then
+      return state[key]
+    end
+    return nil
+  else
+    -- Retained mode: resolve through element field
+    local element = statefulElements[id]
+    if element then
+      return element[key]
+    end
+    return nil
+  end
+end
+
+--- Set a single state value by key for a given element ID.
+--- Works identically in both modes — the caller does not need to know the mode.
+---
+--- Immediate mode: marks dirty for flushFrame() persistence.
+--- Retained mode: writes directly to element field (cache-through).
+---
+---@param id string Element state ID
+---@param key string State key
+---@param value any Value to store
+function StateManager.setStateValue(id, key, value)
+  if not id or not key then
+    ErrorHandler:error("StateManager", "SYS_001", {
+      parameter = "id and key",
+      value = "missing",
+    })
+  end
+
+  -- Update metadata
+  if not stateMetadata[id] then
+    stateMetadata[id] = {
+      lastFrame = frameNumber,
+      createdFrame = frameNumber,
+      accessCount = 1,
+    }
+  else
+    stateMetadata[id].lastFrame = frameNumber
+  end
+
+  if _immediateMode then
+    -- Immediate mode: mark dirty for flushFrame persistence
+    local state = StateManager.getState(id)
+    state[key] = value
+    dirtyState[id] = dirtyState[id] or {}
+    dirtyState[id][key] = true
+  else
+    -- Retained mode: write directly to element field
+    local element = statefulElements[id]
+    if element then
+      element[key] = value
+    end
+  end
+end
+
+-- ====================
+-- Stateful Element Registration (Retained Mode Cache-Through)
+-- ====================
+
+--- Register an element instance for retained-mode cache-through.
+--- After registration, getStateValue/setStateValue will resolve through the element's fields.
+---
+--- Called by Element in _construct phase.
+---
+---@param id string State ID (typically element.id)
+---@param element table Element instance to link
+function StateManager.registerStateful(id, element)
+  if not id or not element then
+    return
+  end
+  statefulElements[id] = element
+end
+
+--- Unregister an element instance.
+--- After unregistration, retained-mode access will fall back to nil.
+---
+--- Called by Element in _cleanup phase.
+---
+---@param id string State ID to unregister
+function StateManager.unregisterStateful(id)
+  if id then
+    statefulElements[id] = nil
+  end
+end
+
+-- ====================
+-- Frame Flush (Immediate Mode Dirty State Persistence)
+-- ====================
+
+--- Flush dirty state to persistent store at end of frame.
+--- Called automatically at frame end in immediate mode.
+--- Behaviors call setStateValue during update without knowing the mode.
+---
+--- In retained mode, this is a no-op (state is written directly to elements).
+function StateManager.flushFrame()
+  if not _immediateMode then
+    return
+  end
+
+  -- All dirty writes were already applied to stateStore during setStateValue
+  -- This method exists for future extensions (e.g., batching, analytics)
+  -- Reset dirty tracking for next frame
+  dirtyState = {}
+end
+
+-- ====================
+-- Mode Configuration
+-- ====================
+
+--- Configure immediate mode state.
+--- Called by Context when immediate mode is enabled/disabled.
+---
+---@param enabled boolean Whether immediate mode is active
+function StateManager.setImmediateMode(enabled)
+  _immediateMode = enabled
+end
+
+--- Check if immediate mode is active.
+---@return boolean
+function StateManager.isImmediateMode()
+  return _immediateMode
+end
+
+--- Whether at-construction layout / eager initialization should run now.
+--- Returns true in retained mode (layout eagerly), false in immediate mode
+--- (layout is deferred to `FlexLove.endFrame` / FlexLove so it runs once all
+--- elements for the frame have been created). This replaces the scattered
+--- `if not _immediateMode then layoutChildren()` mode checks with a single
+--- mode-aware query (behavior-mode-unification task 11).
+---@return boolean
+function StateManager.shouldLayout()
+  return not _immediateMode
+end
+
+-- ====================
+-- Cleanup & Maintenance
+-- ====================
+
+--- Clean up stale states (not accessed recently)
+---@return number count Number of states cleaned up
+function StateManager.cleanup()
+  local cleanedCount = 0
+  local retentionFrames = config.stateRetentionFrames
+
+  for id, meta in pairs(stateMetadata) do
+    local framesSinceAccess = frameNumber - meta.lastFrame
+
+    if framesSinceAccess > retentionFrames then
+      stateStore[id] = nil
+      stateMetadata[id] = nil
+      cleanedCount = cleanedCount + 1
+    end
+  end
+
+  -- Clean up empty states (sparse storage optimization)
+  for id, state in pairs(stateStore) do
+    if next(state) == nil then
+      stateStore[id] = nil
+      stateMetadata[id] = nil
+      cleanedCount = cleanedCount + 1
+    end
+  end
+
+  return cleanedCount
+end
+
+--- Force cleanup if state count exceeds maximum
+---@return number count Number of states cleaned up
+function StateManager.forceCleanupIfNeeded()
+  local stateCount = StateManager.getStateCount()
+
+  if stateCount > config.maxStateEntries then
+    -- Clean up states not accessed in last 10 frames (aggressive)
+    local cleanedCount = 0
+
+    for id, meta in pairs(stateMetadata) do
+      local framesSinceAccess = frameNumber - meta.lastFrame
+
+      if framesSinceAccess > 10 then
+        stateStore[id] = nil
+        stateMetadata[id] = nil
+        cleanedCount = cleanedCount + 1
+      end
+    end
+
+    return cleanedCount
+  end
+
+  return 0
+end
+
+--- Get total number of stored states
+---@return number
+function StateManager.getStateCount()
+  local count = 0
+  for _ in pairs(stateStore) do
+    count = count + 1
+  end
+  return count
+end
+
+--- Clear all states
+function StateManager.clearAllStates()
+  stateStore = {}
+  stateMetadata = {}
+end
+
+--- Configure state management
+---@param newConfig {stateRetentionFrames?: number, maxStateEntries?: number}
+function StateManager.configure(newConfig)
+  if newConfig.stateRetentionFrames then
+    config.stateRetentionFrames = newConfig.stateRetentionFrames
+  end
+  if newConfig.maxStateEntries then
+    config.maxStateEntries = newConfig.maxStateEntries
+  end
+end
+
+--- Get state statistics for debugging
+---@return table stats State usage statistics
+function StateManager.getStats()
+  local stateCount = StateManager.getStateCount()
+  local oldest = nil
+  local newest = nil
+
+  for _, meta in pairs(stateMetadata) do
+    if not oldest or meta.createdFrame < oldest then
+      oldest = meta.createdFrame
+    end
+    if not newest or meta.createdFrame > newest then
+      newest = meta.createdFrame
+    end
+  end
+
+  -- Count callSiteCounters
+  local callSiteCount = 0
+  for _ in pairs(callSiteCounters) do
+    callSiteCount = callSiteCount + 1
+  end
+
+  -- Warn if callSiteCounters is unexpectedly large
+  if callSiteCount > 1000 then
+    if ErrorHandler then
+      ErrorHandler.warn("StateManager", "STATE_001", {
+        count = callSiteCount,
+        expected = "near 0",
+        frameNumber = frameNumber,
+      })
+    end
+  end
+
+  return {
+    stateCount = stateCount,
+    frameNumber = frameNumber,
+    oldestState = oldest,
+    newestState = newest,
+    callSiteCounterCount = callSiteCount,
+  }
+end
+
+--- Get internal state (for debugging/profiling only)
+---@return table internal {stateStore, stateMetadata, callSiteCounters}
+function StateManager._getInternalState()
+  return {
+    stateStore = stateStore,
+    stateMetadata = stateMetadata,
+    callSiteCounters = callSiteCounters,
+  }
+end
+
+--- Reset the entire state system (for testing)
+function StateManager.reset()
+  stateStore = {}
+  stateMetadata = {}
+  frameNumber = 0
+  callSiteCounters = {}
+  statefulElements = {}
+  dirtyState = {}
+  _immediateMode = false
+end
+
+-- ====================
+-- Convenience Functions (for backward compatibility)
+-- ====================
+
+--- Check if an element is currently hovered
+---@param id string Element ID
+---@return boolean
+function StateManager.isHovered(id)
+  local state = StateManager.getState(id)
+  return state.hover or false
+end
+
+--- Check if an element is currently pressed
+---@param id string Element ID
+---@return boolean
+function StateManager.isPressed(id)
+  local state = StateManager.getState(id)
+  return state.pressed or false
+end
+
+--- Check if an element is currently focused
+---@param id string Element ID
+---@return boolean
+function StateManager.isFocused(id)
+  local state = StateManager.getState(id)
+  return state.focused or false
+end
+
+--- Check if an element is disabled
+---@param id string Element ID
+---@return boolean
+function StateManager.isDisabled(id)
+  local state = StateManager.getState(id)
+  return state.disabled or false
+end
+
+--- Check if an element is active (e.g., input focused)
+---@param id string Element ID
+---@return boolean
+function StateManager.isActive(id)
+  local state = StateManager.getState(id)
+  return state.active or false
+end
+
+return StateManager

libs/flexlove/modules/TextSanitizer.lua

@@ -0,0 +1,183 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+-- Text sanitization, escaping, and input validation utilities.
+
+-- ErrorHandler is injected via init() for truncation warnings.
+local ErrorHandler = nil
+
+--- Initialize dependencies
+---@param deps table Dependencies: { ErrorHandler = ErrorHandler }
+local function init(deps)
+  if type(deps) == "table" then
+    ErrorHandler = deps.ErrorHandler
+  end
+end
+
+--- Sanitize text to prevent security vulnerabilities
+--- @param text string? Text to sanitize
+--- @param options table? Sanitization options
+--- @return string Sanitized text
+local function sanitizeText(text, options)
+  local utf8 = require("utf8")
+  -- Handle nil or non-string inputs
+  if text == nil then
+    return ""
+  end
+  if type(text) ~= "string" then
+    text = tostring(text)
+  end
+
+  -- Default options
+  options = options or {}
+  local maxLength = options.maxLength or 10000
+  local allowNewlines = options.allowNewlines ~= false -- default true
+  local allowTabs = options.allowTabs ~= false -- default true
+  local stripControls = options.stripControls ~= false -- default true
+  local trimWhitespace = options.trimWhitespace ~= false -- default true
+
+  -- Remove null bytes (critical security risk)
+  text = text:gsub("%z", "")
+
+  -- Strip control characters except allowed ones
+  if stripControls then
+    local pattern = "[\1-\31\127]" -- All control characters
+    if allowNewlines and allowTabs then
+      pattern = "[\1-\8\11\12\14-\31\127]" -- Exclude \t (9), \n (10), \r (13)
+    elseif allowNewlines then
+      pattern = "[\1-\9\11\12\14-\31\127]" -- Exclude \n (10), \r (13)
+    elseif allowTabs then
+      pattern = "[\1-\8\10\12-\31\127]" -- Exclude \t (9)
+    end
+    text = text:gsub(pattern, "")
+  end
+
+  -- Trim leading/trailing whitespace
+  if trimWhitespace then
+    text = text:match("^%s*(.-)%s*$") or ""
+  end
+
+  -- Limit string length (use UTF-8 character count, not byte count)
+  local charCount = utf8.len(text)
+  if charCount and charCount > maxLength then
+    if ErrorHandler then
+      ErrorHandler:warn("utils", "UTIL_001", {
+        original = charCount,
+        truncated = maxLength,
+      })
+    end
+    -- Truncate to maxLength UTF-8 characters
+    local bytePos = utf8.offset(text, maxLength + 1)
+    if bytePos then
+      text = text:sub(1, bytePos - 1)
+    end
+    if ErrorHandler then
+      ErrorHandler:warn("utils", string.format("Text truncated from %d to %d characters", charCount, maxLength))
+    end
+  end
+
+  return text
+end
+
+--- Validate text input against rules
+--- @param text string Text to validate
+--- @param rules table Validation rules
+--- @return boolean, string? Returns true if valid, or false with error message
+local function validateTextInput(text, rules)
+  rules = rules or {}
+
+  -- Check minimum length
+  if rules.minLength and #text < rules.minLength then
+    return false, string.format("Text must be at least %d characters", rules.minLength)
+  end
+
+  -- Check maximum length
+  if rules.maxLength and #text > rules.maxLength then
+    return false, string.format("Text must be at most %d characters", rules.maxLength)
+  end
+
+  -- Check pattern match
+  if rules.pattern and not text:match(rules.pattern) then
+    return false, rules.patternError or "Text does not match required pattern"
+  end
+
+  -- Check character whitelist
+  if rules.allowedChars then
+    local pattern = "[^" .. rules.allowedChars .. "]"
+    if text:match(pattern) then
+      return false, "Text contains invalid characters"
+    end
+  end
+
+  -- Check character blacklist
+  if rules.forbiddenChars then
+    local pattern = "[" .. rules.forbiddenChars .. "]"
+    if text:match(pattern) then
+      return false, "Text contains forbidden characters"
+    end
+  end
+
+  return true, nil
+end
+
+--- Validate text against range/length rules (alias of validateTextInput)
+--- @param text string Text to validate
+--- @param rules table Validation rules (minLength, maxLength, pattern, etc.)
+--- @return boolean, string? Returns true if valid, or false with error message
+local function validateTextRange(text, rules)
+  return validateTextInput(text, rules)
+end
+
+--- Escape HTML special characters
+--- @param text string Text to escape
+--- @return string Escaped text
+local function escapeHtml(text)
+  if text == nil then
+    return ""
+  end
+  text = tostring(text)
+  text = text:gsub("&", "&amp;")
+  text = text:gsub("<", "&lt;")
+  text = text:gsub(">", "&gt;")
+  text = text:gsub('"', "&quot;")
+  text = text:gsub("'", "&#39;")
+  return text
+end
+
+--- Escape Lua pattern special characters
+--- @param text string Text to escape
+--- @return string Escaped text
+local function escapeLuaPattern(text)
+  if text == nil then
+    return ""
+  end
+  text = tostring(text)
+  -- Escape all Lua pattern special characters
+  text = text:gsub("([%^%$%(%)%%%.%[%]%*%+%-%?])", "%%%1")
+  return text
+end
+
+--- Strip all non-printable characters from text
+--- @param text string Text to clean
+--- @return string Cleaned text
+local function stripNonPrintable(text)
+  if text == nil then
+    return ""
+  end
+  text = tostring(text)
+  -- Keep printable ASCII (32-126), newline (10), tab (9), and carriage return (13)
+  text = text:gsub("[^\9\10\13\32-\126]", "")
+  return text
+end
+
+return {
+  init = init,
+  sanitizeText = sanitizeText,
+  validateTextInput = validateTextInput,
+  validateTextRange = validateTextRange,
+  escapeHtml = escapeHtml,
+  escapeLuaPattern = escapeLuaPattern,
+  stripNonPrintable = stripNonPrintable,
+}

libs/flexlove/modules/UTF8.lua

@@ -0,0 +1,44 @@
+---@class UTF8
+---Compatibility layer for UTF-8 support across Lua versions
+---Handles utf8 (Lua 5.3+), lua-utf8 (LuaRocks), and basic fallbacks
+
+local UTF8 = {}
+
+-- Try to load UTF-8 library in order of preference:
+-- 1. Built-in utf8 (Lua 5.3+, LÖVE2D)
+-- 2. lua-utf8 from LuaRocks (Lua 5.1, 5.2)
+-- 3. Error if neither available
+local function loadUTF8()
+  -- Try built-in utf8 first (Lua 5.3+ and LÖVE2D)
+  if utf8 and type(utf8) == "table" and utf8.len then
+    return utf8
+  end
+
+  -- Try lua-utf8 from LuaRocks
+  local ok, luautf8 = pcall(require, "lua-utf8")
+  if ok then
+    return luautf8
+  end
+
+  -- Try standard utf8 module name as fallback
+  ok, luautf8 = pcall(require, "utf8")
+  if ok then
+    return luautf8
+  end
+
+  -- No UTF-8 library available
+  error("No UTF-8 library available. Please install 'luautf8' via LuaRocks: luarocks install luautf8")
+end
+
+-- Load the UTF-8 implementation
+local utf8lib = loadUTF8()
+
+-- Export all utf8 functions
+UTF8.char = utf8lib.char
+UTF8.charpattern = utf8lib.charpattern
+UTF8.codes = utf8lib.codes
+UTF8.codepoint = utf8lib.codepoint
+UTF8.len = utf8lib.len
+UTF8.offset = utf8lib.offset
+
+return UTF8

libs/flexlove/modules/Units.lua

@@ -0,0 +1,335 @@
+--- Utility module for parsing and resolving CSS-like units (px, %, vw, vh)
+--- Provides unit parsing, validation, and conversion to pixel values
+---@class Units
+---@field _Context table? Context module dependency
+---@field _ErrorHandler table? ErrorHandler module dependency
+---@field _Calc table? Calc module dependency
+local Units = {}
+
+--- Initialize Units module with dependencies
+---@param deps table Dependencies: { Context = table?, ErrorHandler = table?, Calc = table? }
+function Units.init(deps)
+  Units._Context = deps.Context
+  Units._ErrorHandler = deps.ErrorHandler
+  Units._Calc = deps.Calc
+end
+
+--- Parse a unit value into numeric value and unit type
+--- Supports: px (pixels), % (percentage), vw/vh (viewport), and calc() expressions
+---@param value string|number|table The value to parse (e.g., "50px", "10%", "2vw", 100, or calc object)
+---@return number|table numericValue The numeric portion of the value or calc object
+---@return string unitType The unit type ("px", "%", "vw", "vh", "calc")
+function Units.parse(value)
+  -- Check if value is a calc expression
+  if Units._Calc and Units._Calc.isCalc(value) then
+    return value, "calc"
+  end
+
+  if type(value) == "number" then
+    return value, "px"
+  end
+
+  if type(value) ~= "string" and type(value) ~= "table" then
+    Units._ErrorHandler:warn("Units", "VAL_001", {
+      property = "unit value",
+      expected = "string, number, or calc object",
+      got = type(value),
+    })
+    return 0, "px"
+  end
+
+  -- Check for unit-only input (e.g., "px", "%", "vw" without a number)
+  local validUnits = { px = true, ["%"] = true, vw = true, vh = true }
+  if validUnits[value] then
+    Units._ErrorHandler:warn("Units", "VAL_005", {
+      input = value,
+      expected = "number + unit (e.g., '50" .. value .. "')",
+    })
+    return 0, "px"
+  end
+
+  -- Check for invalid format (space between number and unit)
+  if value:match("%d%s+%a") then
+    Units._ErrorHandler:warn("Units", "VAL_005", {
+      input = value,
+      issue = "contains space between number and unit",
+    })
+    return 0, "px"
+  end
+
+  -- Match number followed by optional unit
+  local numStr, unit = value:match("^([%-]?[%d%.]+)(.*)$")
+  if not numStr then
+    Units._ErrorHandler:warn("Units", "VAL_005", {
+      input = value,
+    })
+    return 0, "px"
+  end
+
+  local num = tonumber(numStr)
+  if not num then
+    Units._ErrorHandler:warn("Units", "VAL_005", {
+      input = value,
+      issue = "numeric value cannot be parsed",
+    })
+    return 0, "px"
+  end
+
+  -- Default to pixels if no unit specified
+  if unit == "" then
+    unit = "px"
+  end
+
+  -- validUnits is already defined at the top of the function
+  if not validUnits[unit] then
+    Units._ErrorHandler:warn("Units", "VAL_005", {
+      input = value,
+      unit = unit,
+      validUnits = "px, %, vw, vh",
+    })
+    return num, "px"
+  end
+
+  return num, unit
+end
+
+--- Convert relative units to absolute pixel values
+--- Resolves %, vw, vh units based on viewport and parent dimensions, and evaluates calc() expressions
+---@param value number|table Numeric value to convert or calc object
+---@param unit string Unit type ("px", "%", "vw", "vh", "calc")
+---@param viewportWidth number Current viewport width in pixels
+---@param viewportHeight number Current viewport height in pixels
+---@param parentSize number? Required for percentage units (parent dimension in pixels)
+---@return number resolvedValue Resolved pixel value
+function Units.resolve(value, unit, viewportWidth, viewportHeight, parentSize)
+  if unit == "calc" then
+    -- Resolve calc expression
+    if Units._Calc then
+      return Units._Calc.resolve(value, viewportWidth, viewportHeight, parentSize)
+    else
+      Units._ErrorHandler:warn("Units", "VAL_006", {
+        unit = "calc",
+        issue = "Calc module not available",
+      })
+      return 0
+    end
+  elseif unit == "px" then
+    return value
+  elseif unit == "%" then
+    if not parentSize then
+      Units._ErrorHandler:warn("Units", "LAY_003", {
+        unit = "%",
+        issue = "parent dimension not available",
+      })
+      return 0
+    end
+    return (value / 100) * parentSize
+  elseif unit == "vw" then
+    return (value / 100) * viewportWidth
+  elseif unit == "vh" then
+    return (value / 100) * viewportHeight
+  else
+    Units._ErrorHandler:warn("Units", "VAL_005", {
+      unit = unit,
+      validUnits = "px, %, vw, vh, calc",
+    })
+    return 0
+  end
+end
+
+--- Get current viewport dimensions
+--- Uses cached viewport during resize operations, otherwise queries LÖVE graphics
+---@return number width Viewport width in pixels
+---@return number height Viewport height in pixels
+function Units.getViewport()
+  -- Return cached viewport if available (only during resize operations)
+  if Units._Context._cachedViewport and Units._Context._cachedViewport.width > 0 then
+    return Units._Context._cachedViewport.width, Units._Context._cachedViewport.height
+  end
+
+  if love.graphics and love.graphics.getDimensions then
+    return love.graphics.getDimensions()
+  else
+    local w, h = love.window.getMode()
+    return w, h
+  end
+end
+
+--- Apply base scale factor to a value based on axis
+--- Used for responsive scaling of UI elements
+---@param value number The value to scale
+---@param axis "x"|"y" The axis to scale on
+---@param scaleFactors {x:number, y:number} Scale factors for each axis
+---@return number scaledValue The scaled value
+function Units.applyBaseScale(value, axis, scaleFactors)
+  if axis == "x" then
+    return value * scaleFactors.x
+  else
+    return value * scaleFactors.y
+  end
+end
+
+--- Resolve spacing properties (margin, padding) to pixel values
+--- Supports individual sides (top, right, bottom, left) and shortcuts (vertical, horizontal)
+---@param spacingProps table? Spacing properties with top/right/bottom/left/vertical/horizontal
+---@param parentWidth number Parent element width in pixels
+---@param parentHeight number Parent element height in pixels
+---@return table resolvedSpacing Table with top, right, bottom, left in pixels
+function Units.resolveSpacing(spacingProps, parentWidth, parentHeight)
+  if not spacingProps then
+    return { top = 0, right = 0, bottom = 0, left = 0 }
+  end
+
+  local viewportWidth, viewportHeight = Units.getViewport()
+  local result = {}
+
+  local vertical = spacingProps.vertical
+  local horizontal = spacingProps.horizontal
+
+  if vertical then
+    if type(vertical) == "string" or (Units._Calc and Units._Calc.isCalc(vertical)) then
+      local value, unit = Units.parse(vertical)
+      vertical = Units.resolve(value, unit, viewportWidth, viewportHeight, parentHeight)
+    end
+  end
+
+  if horizontal then
+    if type(horizontal) == "string" or (Units._Calc and Units._Calc.isCalc(horizontal)) then
+      local value, unit = Units.parse(horizontal)
+      horizontal = Units.resolve(value, unit, viewportWidth, viewportHeight, parentWidth)
+    end
+  end
+
+  for _, side in ipairs({ "top", "right", "bottom", "left" }) do
+    local value = spacingProps[side]
+    if value then
+      if type(value) == "string" or (Units._Calc and Units._Calc.isCalc(value)) then
+        local numValue, unit = Units.parse(value)
+        local parentSize = (side == "top" or side == "bottom") and parentHeight or parentWidth
+        result[side] = Units.resolve(numValue, unit, viewportWidth, viewportHeight, parentSize)
+      else
+        result[side] = value
+      end
+    else
+      if side == "top" or side == "bottom" then
+        result[side] = vertical or 0
+      else
+        result[side] = horizontal or 0
+      end
+    end
+  end
+
+  return result
+end
+
+--- Validate a unit string format
+--- Checks if the string can be successfully parsed as a valid unit or calc expression
+---@param unitStr string|table The unit string to validate (e.g., "50px", "10%") or calc object
+---@return boolean isValid True if the unit string is valid, false otherwise
+function Units.isValid(unitStr)
+  -- Check if it's a calc expression
+  if Units._Calc and Units._Calc.isCalc(unitStr) then
+    return true
+  end
+
+  if type(unitStr) ~= "string" then
+    return false
+  end
+
+  -- Check for invalid format (space between number and unit)
+  if unitStr:match("%d%s+%a") then
+    return false
+  end
+
+  -- Match number followed by optional unit
+  local numStr, unit = unitStr:match("^([%-]?[%d%.]+)(.*)$")
+  if not numStr then
+    return false
+  end
+
+  -- Check if numeric part is valid
+  local num = tonumber(numStr)
+  if not num then
+    return false
+  end
+
+  -- Default to pixels if no unit specified
+  if unit == "" then
+    unit = "px"
+  end
+
+  -- Check if unit is valid
+  local validUnits = { px = true, ["%"] = true, vw = true, vh = true }
+  return validUnits[unit] == true
+end
+
+--- Parse CSS flex shorthand into flexGrow, flexShrink, flexBasis
+--- Supports: number, "auto", "none", "grow shrink basis"
+---@param flexValue number|string The flex shorthand value
+---@return number flexGrow
+---@return number flexShrink
+---@return string|number flexBasis
+function Units.parseFlexShorthand(flexValue)
+  -- Single number: flex-grow
+  if type(flexValue) == "number" then
+    return flexValue, 1, 0
+  end
+
+  -- String values
+  if type(flexValue) == "string" then
+    -- "auto" = 1 1 auto
+    if flexValue == "auto" then
+      return 1, 1, "auto"
+    end
+
+    -- "none" = 0 0 auto
+    if flexValue == "none" then
+      return 0, 0, "auto"
+    end
+
+    -- Parse "grow shrink basis" format
+    local parts = {}
+    for part in flexValue:gmatch("%S+") do
+      table.insert(parts, part)
+    end
+
+    local grow = 0
+    local shrink = 1
+    local basis = "auto"
+
+    if #parts == 1 then
+      -- Single value: could be grow (number) or basis (with unit)
+      local num = tonumber(parts[1])
+      if num then
+        grow = num
+        basis = 0
+      else
+        basis = parts[1]
+      end
+    elseif #parts == 2 then
+      -- Two values: grow shrink (both numbers) or grow basis
+      local num1 = tonumber(parts[1])
+      local num2 = tonumber(parts[2])
+      if num1 and num2 then
+        grow = num1
+        shrink = num2
+        basis = 0
+      elseif num1 then
+        grow = num1
+        basis = parts[2]
+      end
+    elseif #parts >= 3 then
+      -- Three values: grow shrink basis
+      grow = tonumber(parts[1]) or 0
+      shrink = tonumber(parts[2]) or 1
+      basis = parts[3]
+    end
+
+    return grow, shrink, basis
+  end
+
+  -- Default fallback
+  return 0, 1, "auto"
+end
+
+return Units

libs/flexlove/modules/ZIndex.lua

@@ -0,0 +1,35 @@
+---@class ZIndex
+local ZIndex = {}
+
+-- The effective z-index formula used for sorting is:
+--   rootZ * ROOT_WEIGHT + depth * DEPTH_WEIGHT + ownZ
+-- where rootZ is the z-index of the top-level ancestor, depth is the
+-- nesting level, and ownZ is the element's own z property.
+--
+-- Constraints enforced by these weights:
+--   |ownZ| <= MAX_Z   (must fit within DEPTH_WEIGHT digits)
+--   DEPTH_WEIGHT has enough room for depths well beyond any practical tree
+--   ROOT_WEIGHT has enough room for the rootZ without exceeding double-precision
+---
+---@type integer
+ZIndex.MIN_Z = -999
+---@type integer
+ZIndex.MAX_Z = 999
+---@type integer
+ZIndex.ROOT_WEIGHT = 10000000000
+---@type integer
+ZIndex.DEPTH_WEIGHT = 1000
+
+--- Clamp a z-index value to the valid range
+---@param value number
+---@return integer
+function ZIndex.clamp(value)
+  if value < ZIndex.MIN_Z then
+    return ZIndex.MIN_Z
+  elseif value > ZIndex.MAX_Z then
+    return ZIndex.MAX_Z
+  end
+  return value
+end
+
+return ZIndex

libs/flexlove/modules/behaviors/Animated.lua

@@ -0,0 +1,245 @@
+-- modules/behaviors/Animated.lua
+--
+-- Concrete behavior: animation update, interpolation application, chaining
+-- resolution, and transition wiring.
+--
+-- Task 06 of the behavior-mode-unification refactor. Moves the entire
+-- animation-update block out of Element:update (lines ~2761-2800) into
+-- `Animated.onUpdate(element, dt)`, and the `_ColorModule`/`_TransformModule`
+-- init-time wiring into `Animated.onAttach(element)`.
+--
+-- This behavior is UNIQUE among the behavior set because it can attach
+-- AFTER element creation. Animation is opt-in: a plain Element created without
+-- `transitions` and without an `animation` field never attaches Animated.
+-- The moment something creates an animation on the element — either directly
+-- (`element.animation = Animation.new(...)`, `element:fadeIn(...)`) or via a
+-- transition firing in `setProperty` — `Animated.ensureAttached(element)`
+-- attaches this behavior on demand so subsequent `Element:update` frames
+-- dispatch to `Animated.onUpdate`.
+--
+-- Attachment rule (shouldAttach): true when `props.transitions` is set OR an
+-- `element.animation` already exists at runtime. The runtime arm covers the
+-- late-attach case (animateTo / fadeIn / direct animation assignment).
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (`element.animation`).
+--   * The behavior instance itself is stateless and shared across elements.
+--   * Element-class-level dependencies (Element._Animation, Element._Color,
+--     Element._Transform) are resolved from the owning element's metatable,
+--     exactly like Clickable does — keeping the behavior stateless without
+--     expanding the 6-hook signature.
+--
+-- saveState/restoreState are no-ops: animations are ephemeral (an in-flight
+-- animation is not part of immediate-mode persisted state — the next frame
+-- re-evaluates transitions / re-applies animations fresh). Persisted scalar
+-- props (`opacity`, `x`, ...) survive via Element.saveState's `_props` block,
+-- not via the animation.
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance.
+-- Element instances are created via `setmetatable({}, Element)` in _construct,
+-- so their metatable IS the Element class — giving us Element._Animation,
+-- Element._Color, Element._Transform, etc. without threading deps through the
+-- behavior hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- ensureAnimationModuleWiring — set Element._Animation._ColorModule /
+-- _TransformModule. Idempotent; called from both onAttach and onUpdate so it
+-- works even when an animation was assigned by a caller that bypassed
+-- onAttach (direct `element.animation = Animation.new(...)`).
+-- ----------------------------------------------------------------------------
+
+local function ensureAnimationModuleWiring(element)
+  local Element = ElementClass(element)
+  local Animation = Element._Animation
+  if not Animation then
+    return
+  end
+  -- Ensure animation has Color module reference for color interpolation
+  if not Animation._ColorModule and Element._Color then
+    Animation._ColorModule = Element._Color
+  end
+  -- Ensure animation has Transform module reference for transform interpolation
+  if not Animation._TransformModule and Element._Transform then
+    Animation._TransformModule = Element._Transform
+  end
+end
+
+-- ----------------------------------------------------------------------------
+-- shouldAttach (class-level predicate, no element required)
+-- ----------------------------------------------------------------------------
+
+-- True when the element declares transitions up front OR already has an
+-- animation attached. The `animation` arm is consulted by ensureAttached at
+-- runtime (after creation); the `transitions` arm lets Animated auto-attach
+-- during Element.new for elements that pre-declare transitions.
+local function shouldAttach(props)
+  if not props then
+    return false
+  end
+  if props.transitions ~= nil then
+    return true
+  end
+  -- Late-attach case: an animation was assigned after creation. When ensure
+  -- Attached passes the element instance as `props`, this arm catches it.
+  if type(props) == "table" and props.animation ~= nil then
+    return true
+  end
+  return false
+end
+
+-- ----------------------------------------------------------------------------
+-- ensureAttached — dynamic late-attach entry point
+-- ----------------------------------------------------------------------------
+
+-- Idempotently attach the Animated behavior to an element that just gained an
+-- animation (via animateTo / fadeIn / direct assignment / a firing transition
+-- in setProperty). Called from Element.setProperty when a transition fires and
+-- from the transition helper methods on Element. Safe to call when already
+-- attached (no-op / returns false).
+--
+-- `animatedBehavior` is the shared behavior instance resolved lazily by
+-- Element (see Element._resolveAnimatedBehavior). The behavior is looked up
+-- from the registry once and cached on the class.
+--
+-- Returns true if the behavior was attached this call, false otherwise.
+local function ensureAttached(element, animatedBehavior)
+  if not element or not animatedBehavior then
+    return false
+  end
+  -- Already attached? Avoid duplicate entries within one element lifetime
+  -- (a behavior may legitimately be re-added across immediate-mode frames
+  -- since Element is recreated each frame, but within one lifetime at most
+  -- once).
+  local behaviors = element.behaviors
+  if behaviors then
+    for i = 1, #behaviors do
+      if behaviors[i] == animatedBehavior then
+        return false
+      end
+    end
+  end
+  table.insert(element.behaviors, animatedBehavior)
+  animatedBehavior.onAttach(element)
+  return true
+end
+
+-- ----------------------------------------------------------------------------
+-- onAttach — initialize Animation module references (formerly the
+-- Element._Animation._ColorModule / _TransformModule wiring in Element:update
+-- lines ~2772-2778).
+-- ----------------------------------------------------------------------------
+
+local function onAttach(element)
+  ensureAnimationModuleWiring(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- onUpdate — the animation update + interpolation + chain-resolution block
+-- (formerly Element:update lines ~2761-2800).
+-- ----------------------------------------------------------------------------
+
+local function onUpdate(element, dt)
+  local animation = element.animation
+  if not animation then
+    return
+  end
+
+  -- (Re)ensure module wiring is present in case the Animation instance was
+  -- created by a caller that bypassed onAttach (e.g. direct
+  -- `element.animation = Animation.new(...)`). Cheap idempotent writes.
+  ensureAnimationModuleWiring(element)
+
+  local finished = animation:update(dt, element)
+  if finished then
+    -- Animation:update() already called onComplete callback.
+    -- Check for chained animation.
+    if animation._next then
+      element.animation = animation._next
+    elseif animation._nextFactory and type(animation._nextFactory) == "function" then
+      local success, nextAnim = pcall(animation._nextFactory, element)
+      if success and nextAnim then
+        element.animation = nextAnim
+      else
+        element.animation = nil
+      end
+    else
+      element.animation = nil
+    end
+  else
+    -- Apply animation interpolation during update.
+    animation:applyInterpolation(element)
+  end
+end
+
+-- ----------------------------------------------------------------------------
+-- saveState / restoreState — no-ops (animations are ephemeral).
+-- ----------------------------------------------------------------------------
+
+-- Animations are not persisted across immediate-mode frames — they are
+-- re-derived each frame from transitions / direct calls. The element's scalar
+-- props (opacity, x, ...) are persisted by Element.saveState's _props block,
+-- so a completed animation's final visual state still survives recreation.
+-- While an animation is mid-flight in immediate mode, the element is recreated
+-- and the animation is NOT carried over (intentional — animating in immediate
+-- mode requires setting up the animation each frame).
+local function saveState()
+  return nil
+end
+
+local function restoreState()
+  return nil
+end
+
+-- ----------------------------------------------------------------------------
+-- Build the (stateless, shared) behavior instance.
+-- ----------------------------------------------------------------------------
+
+-- onDetach/onDraw omitted: they default to no-ops (the behavior allocates no
+-- behavior-local state and animations have no draw pass). Animation state lives
+-- on the element (`element.animation`); nothing to tear down on detach.
+--
+-- We build the immutable behavior via Behavior.new (for validation + freeze +
+-- isBehavior parity with Clickable), then expose the late-attach helper on a
+-- thin module table since the frozen instance cannot accept new keys. The
+-- module table passes the behavior to the registry while making
+-- `Animated.ensureAttached` callable from Element.setProperty / the transition
+-- helpers — exactly as the task spec requires.
+local behavior = Behavior.new({
+  onAttach = onAttach,
+  onUpdate = onUpdate,
+  saveState = saveState,
+  restoreState = restoreState,
+  shouldAttach = shouldAttach,
+})
+
+-- Thin module table: exposes the behavior instance (for the registry) plus the
+-- late-attach helper (for Element.setProperty). All hooks delegate to the
+-- frozen behavior instance so dispatch sites get the validated, frozen
+-- implementation. shouldAttach is also exposed at module level (mirrors
+-- Clickable.shouldAttach) for tests/callers without an element.
+local Animated = {
+  behavior = behavior,
+  ensureAttached = ensureAttached,
+  shouldAttach = shouldAttach,
+  onAttach = onAttach,
+  onUpdate = onUpdate,
+}
+
+-- Metatable so the module table itself satisfies the duck-typed registry
+-- contract (iterating `Element._behaviorRegistry` calls `behavior.shouldAttach`
+-- and `behavior.onAttach` / `behavior.onUpdate` directly). Falls through to the
+-- frozen behavior instance for every hook.
+setmetatable(Animated, {
+  __index = behavior,
+  __tostring = function()
+    return "Animated"
+  end,
+})
+
+return Animated

libs/flexlove/modules/behaviors/Clickable.lua

@@ -0,0 +1,344 @@
+-- modules/behaviors/Clickable.lua
+--
+-- Concrete behavior: mouse/touch event handling, pressed-state tracking,
+-- hit-testing, and theme-state sync.
+--
+-- This is the largest behavior in the behavior-mode-unification refactor
+-- (~200 LOC moved out of Element:update / _initSubSystems / saveState).
+-- Task 02 extracts the entire `if self.onEvent or self.themeComponent or
+-- self.editable or self._selectState or self.selectOption then ... end` block
+-- from Element:update (hit-testing, mouse/touch event processing, immediate-
+-- mode state save, theme-state update) plus EventHandler creation (formerly the
+-- first half of Element:_initSubSystems) plus pressed-state drawing (formerly a
+-- render layer in Renderer) plus EventHandler save/restore.
+--
+-- Attachment rule (shouldAttach): the same predicate that previously guarded
+-- mouse-event processing in Element:update. An element owns the EventHandler /
+-- gets press feedback exactly when it is interactive: when it declares an
+-- `onEvent` callback, a `themeComponent`, is `editable`, or participates in a
+-- Select group (selectParent / selectOption). A plain passive element never
+-- attaches Clickable and therefore never allocates an EventHandler.
+--
+-- Element retains only the `self._eventHandler` field; Clickable owns it on
+-- attach. All other Element paths that touched the EventHandler (handleTouchEvent,
+-- handleGesture, getTouches) already nil-guard `self._eventHandler`, so they keep
+-- working unchanged for non-clickable elements.
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (self._eventHandler etc.).
+--   * The behavior instance itself is stateless and shared across elements.
+--   * Element-class-level dependencies (EventHandler factory, StateManager,
+--     Context) are resolved from the owning element's metatable (the Element
+--     class set by Element:_construct). This keeps the behavior stateless while
+--     avoiding a dependency-injection parameter that would violate the locked
+--     6-hook signature `(element, ...)`.
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance.
+-- Element instances are created via `setmetatable({}, Element)` in _construct,
+-- so their metatable IS the Element class — giving us Element._EventHandler,
+-- Element._eventHandlerDeps, Element._StateManager, Element._Context, etc.
+-- without threading deps through the behavior hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- shouldAttach (class-level predicate, no element required)
+-- ----------------------------------------------------------------------------
+
+-- Mirrors the cases that previously caused Element to allocate + use an
+-- EventHandler. MUST cover every element that touches the EventHandler at
+-- runtime: click (onEvent), theme press-feedback (themeComponent), text mouse
+-- interaction (editable), Select groups (selectParent / selectOption), touch
+-- callbacks (onTouchEvent), and gesture callbacks (onGesture). selectParent /
+-- selectOption are the props that produce _selectState during _initSubSystems;
+-- checking the props (rather than the runtime _selectState) lets shouldAttach
+-- run before the Select subsystem is initialized.
+local function shouldAttach(props)
+  props = props or {}
+  return props.onEvent ~= nil
+    or props.themeComponent ~= nil
+    or props.editable == true
+    or props.onTouchEvent ~= nil
+    or props.onGesture ~= nil
+    or props.selectOption ~= nil
+    or props.selectParent ~= nil
+end
+
+-- ----------------------------------------------------------------------------
+-- onAttach — create the EventHandler (formerly Element:_initSubSystems
+-- lines ~640-690) and restore immediate-mode EventHandler state.
+-- ----------------------------------------------------------------------------
+
+local function onAttach(element)
+  local Element = ElementClass(element)
+
+  local eventHandlerConfig = {
+    -- element.onEvent is source of truth; not cached on handler
+    onEventDeferred = element.onEventDeferred,
+    -- element.onTouchEvent is source of truth; not cached on handler
+    onTouchEventDeferred = element.onTouchEventDeferred,
+    -- element.onGesture is source of truth; not cached on handler
+    onGestureDeferred = element.onGestureDeferred,
+    touchEnabled = element.touchEnabled,
+    multiTouchEnabled = element.multiTouchEnabled,
+  }
+
+  -- In immediate mode, restore EventHandler state from StateManager so pressed
+  -- / hovered / click-count survive the per-frame element recreation cycle.
+  -- Mode-aware via Context.isImmediateMode (behavior-mode-unification task 11):
+  -- in retained mode the eventHandler persists, so nothing to restore.
+  if Element._Context.isImmediateMode() and element._stateId and element._stateId ~= "" then
+    local state = Element._StateManager.getState(element._stateId)
+    if state then
+      -- Restore EventHandler state from StateManager (sparse storage — provide defaults)
+      eventHandlerConfig._pressed = state._pressed or {}
+      eventHandlerConfig._lastClickTime = state._lastClickTime
+      eventHandlerConfig._lastClickButton = state._lastClickButton
+      eventHandlerConfig._clickCount = state._clickCount or 0
+      eventHandlerConfig._dragStartX = state._dragStartX or {}
+      eventHandlerConfig._dragStartY = state._dragStartY or {}
+      eventHandlerConfig._lastMouseX = state._lastMouseX or {}
+      eventHandlerConfig._lastMouseY = state._lastMouseY or {}
+      eventHandlerConfig._hovered = state._hovered
+    end
+  end
+
+  element._eventHandler = Element._EventHandler.new(eventHandlerConfig, Element._eventHandlerDeps)
+end
+
+local function onDetach(element)
+  -- Clear focus callbacks read by KeyboardNavigation / TextEditor:focus so the
+  -- element's closure references can be collected in immediate mode (formerly
+  -- part of Element:_cleanup). The EventHandler instance itself is INTENTIONALLY
+  -- kept: Element:_cleanup preserves element structure for inspection (the
+  -- stale-element refs are released when the element is GC'd). onEvent,
+  -- onTouchEvent, onGesture are also left intact — the Renderer/EventHandler
+  -- read those directly from the element (not the cache), so clearing them
+  -- would break retained mode.
+  element.onFocus = nil
+  element.onBlur = nil
+end
+
+-- ----------------------------------------------------------------------------
+-- onUpdate — the mouse hit-testing + event-processing + theme-state +
+-- immediate-mode save block (formerly Element:update lines ~2813-2960).
+-- ----------------------------------------------------------------------------
+
+local function onUpdate(element, dt)
+  local Element = ElementClass(element)
+  local eventHandler = element._eventHandler
+  if not eventHandler then
+    return
+  end
+
+  local mx, my = love.mouse.getPosition()
+
+  -- Clickable area is the border box (x, y already includes padding)
+  -- BORDER-BOX MODEL: Use stored border-box dimensions for hit detection
+  local bx = element.x
+  local by = element.y
+  local bw = element._borderBoxWidth or (element.width + element.padding.left + element.padding.right)
+  local bh = element._borderBoxHeight or (element.height + element.padding.top + element.padding.bottom)
+
+  -- Account for scroll offsets from parent containers
+  -- Walk up the parent chain and accumulate scroll offsets. This stays in
+  -- Clickable because it's an interaction concern (hit-testing), not layout.
+  local scrollOffsetX = 0
+  local scrollOffsetY = 0
+  local current = element.parent
+  while current do
+    local overflowX = current.overflowX or current.overflow
+    local overflowY = current.overflowY or current.overflow
+    local hasScrollableOverflow = (
+      overflowX == "scroll"
+      or overflowX == "auto"
+      or overflowY == "scroll"
+      or overflowY == "auto"
+      or overflowX == "hidden"
+      or overflowY == "hidden"
+    )
+    if hasScrollableOverflow then
+      scrollOffsetX = scrollOffsetX + (current._scrollX or 0)
+      scrollOffsetY = scrollOffsetY + (current._scrollY or 0)
+    end
+    current = current.parent
+  end
+
+  -- Adjust mouse position by accumulated scroll offset for hit testing
+  local adjustedMx = mx + scrollOffsetX
+  local adjustedMy = my + scrollOffsetY
+  local isHovering = adjustedMx >= bx and adjustedMx <= bx + bw and adjustedMy >= by and adjustedMy <= by + bh
+
+  -- Check if this is the topmost interactive element at the mouse position
+  -- (z-index ordering). This prevents blocked/occluded elements from
+  -- receiving interactions or visual feedback. A single mode-agnostic lookup
+  -- via `Context.findInteractiveAtPosition` (unified-event-routing task 05)
+  -- replaces the previous immediate/retained-mode split that used
+  -- `getTopElementAt` in immediate mode and `_activeEventElement` in retained
+  -- mode. `findInteractiveAtPosition` routes every hit test through
+  -- `pointHitsElement` (the single canonical `display == false` guard) and
+  -- resolves occlusion by z-index in both modes, so the active element is the
+  -- same one that would receive a hit under the cursor.
+  local topElement = Element._Context.findInteractiveAtPosition(mx, my)
+  local isActiveElement = (topElement == element or topElement == nil)
+
+  -- Reset scrollbar press flag at start of each frame
+  eventHandler:resetScrollbarPressFlag()
+
+  -- Process mouse events through EventHandler FIRST
+  -- This ensures pressed states are updated before theme state is calculated
+  eventHandler:processMouseEvents(element, mx, my, isHovering, isActiveElement)
+
+  -- In immediate mode, save EventHandler state to StateManager after
+  -- processing events so it survives the per-frame recreation.
+  if element._stateId and Element._Context.isImmediateMode() and element._stateId ~= "" then
+    local eventHandlerState = eventHandler:getState()
+    Element._StateManager.updateState(element._stateId, {
+      _pressed = eventHandlerState._pressed,
+      _lastClickTime = eventHandlerState._lastClickTime,
+      _lastClickButton = eventHandlerState._lastClickButton,
+      _clickCount = eventHandlerState._clickCount,
+      _dragStartX = eventHandlerState._dragStartX,
+      _dragStartY = eventHandlerState._dragStartY,
+      _lastMouseX = eventHandlerState._lastMouseX,
+      _lastMouseY = eventHandlerState._lastMouseY,
+      _hovered = eventHandlerState._hovered,
+    })
+  end
+
+  -- Update theme state based on interaction. themeComponent state update
+  -- lives in Clickable because it is driven by hover/press state; the actual
+  -- theme RENDERING is the Themed behavior (task 07).
+  if element.themeComponent then
+    -- Check if any button is pressed via EventHandler
+    local anyPressed = eventHandler:isAnyButtonPressed()
+
+    -- Update theme state via ThemeManager
+    local isFocused = Element._Context.getFocused() == element
+    local newThemeState =
+      element._themeManager:updateState(isHovering and isActiveElement, anyPressed, isFocused, element.disabled)
+
+    if element._stateId and Element._Context.isImmediateMode() then
+      local hover = newThemeState == "hover"
+      local pressed = newThemeState == "pressed"
+      local focused = isFocused
+
+      Element._StateManager.updateState(element._stateId, {
+        hover = hover,
+        pressed = pressed,
+        focused = focused,
+        disabled = element.disabled,
+        active = element.active,
+      })
+    end
+
+    if element._renderer then
+      element._renderer:setThemeState(newThemeState)
+    end
+  end
+
+  -- Process touch events through EventHandler
+  eventHandler:processTouchEvents(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- onDraw — pressed-state visual feedback (formerly Renderer Layer 5).
+-- ----------------------------------------------------------------------------
+
+-- Draws the grey pressed overlay when any mouse button is currently pressed on
+-- the element. Delegates the actual pixels to Renderer:drawPressedState (which
+-- owns the RoundedRect + opacity math) but drives the DECISION + transform
+-- context here, so the renderer no longer needs the `if element.onEvent ...`
+-- behavioral branch. Honors disableHighlight (themes handle their own visual
+-- feedback) exactly as the old render layer did.
+local function onDraw(element)
+  if element.disableHighlight then
+    return
+  end
+  local eventHandler = element._eventHandler
+  if not eventHandler then
+    return
+  end
+
+  local anyPressed = false
+  local pressedState = eventHandler:getState()._pressed or {}
+  for _, pressed in pairs(pressedState) do
+    if pressed then
+      anyPressed = true
+      break
+    end
+  end
+  if not anyPressed then
+    return
+  end
+
+  local renderer = element._renderer
+  if not renderer then
+    return
+  end
+
+  local bw = element._borderBoxWidth or (element.width + element.padding.left + element.padding.right)
+  local bh = element._borderBoxHeight or (element.height + element.padding.top + element.padding.bottom)
+
+  -- Apply the element transform around the overlay, mirroring how the
+  -- Renderer wrapped its whole command buffer (pressed state was a render
+  -- layer subject to the same transform).
+  local Element = ElementClass(element)
+  local Transform = Element._Transform
+  local hasTransform = element.transform ~= nil and Transform ~= nil and not Transform.isIdentity(element.transform)
+  if hasTransform then
+    Transform.apply(element.transform, element.x, element.y, element.width, element.height)
+  end
+
+  renderer:drawPressedState(element.x, element.y, bw, bh, element.opacity, element.cornerRadius)
+
+  if hasTransform then
+    Transform.unapply()
+  end
+end
+
+-- ----------------------------------------------------------------------------
+-- saveState / restoreState — EventHandler state (formerly the eventHandler
+-- branches of Element:saveState / Element:restoreState).
+-- ----------------------------------------------------------------------------
+
+local function saveState(element)
+  if element._eventHandler then
+    return { eventHandler = element._eventHandler:getState() }
+  end
+  return nil
+end
+
+local function restoreState(element, state)
+  if not state then
+    return nil
+  end
+  if element._eventHandler and state.eventHandler then
+    element._eventHandler:setState(state.eventHandler)
+  end
+  return nil
+end
+
+-- ----------------------------------------------------------------------------
+-- Build the (stateless, shared, immutable) behavior instance.
+-- ----------------------------------------------------------------------------
+
+local Clickable = Behavior.new({
+  onAttach = onAttach,
+  onDetach = onDetach,
+  onUpdate = onUpdate,
+  onDraw = onDraw,
+  saveState = saveState,
+  restoreState = restoreState,
+  shouldAttach = shouldAttach,
+})
+
+-- Expose the predicate at module level so callers/tests can reference it
+-- directly without an element instance (mirrors Behavior.shouldAttach).
+Clickable.shouldAttach = shouldAttach
+
+return Clickable

libs/flexlove/modules/behaviors/Imageable.lua

@@ -0,0 +1,282 @@
+-- modules/behaviors/Imageable.lua
+--
+-- Concrete behavior: image loading + image rendering config.
+--
+-- Imageable owns the image side of the Renderer: it runs the deferred image-
+-- load pipeline (cache check → defer → load → fire onImageLoad/onImageError
+-- callbacks), populates the resolved `_loadedImage` cache on both the element
+-- and the shared renderer, and persists that cache across immediate-mode
+-- recreation. It is the behavior-mode-unification replacement for the image-
+-- loading half of Element:_initImageAndRenderer and the deferred
+-- Element:_loadImage method (behavior-mode-unification task 07).
+--
+-- Image value props (imagePath/image/objectFit/objectPosition/imageOpacity/
+-- imageRepeat/imageTint) are bound on the ELEMENT by Element:_applyProps and read
+-- from the element at draw time (Renderer._executeDrawCommand image branch) —
+-- Imageable does NOT mirror them onto the renderer, so bare writes and
+-- setProperty(...) are immediately consistent. Only the resolved _loadedImage
+-- cache (the love.Image produced by the load pipeline) is renderer-mirrored,
+-- because Renderer:draw reads `self._loadedImage`.
+--
+-- Runtime reload: setProperty("imagePath", ...) / setProperty("image", ...) and
+-- the bare-write-equivalent setImage* flows route through element._reloadImage
+-- (installed below) which re-runs the load pipeline. See
+-- TestRetainedPropertyConsistency (image props) and TestImageableIntegration.
+--
+-- Attachment rule (shouldAttach): an element owns image concern exactly when it
+-- declares an `imagePath` (load-from-path) or a direct `image` (already-loaded
+-- love.Image). Mirrors the old `if self.imagePath / if self.image` init branches.
+--
+-- Pairing with Themed: Themed.onAttach creates the Renderer with theme/blur
+-- config; Imageable.onAttach enriches the SAME renderer instance with image
+-- config + kicks off loading. They share `element._renderer`. In the registry
+-- Imageable runs after Themed, so the renderer already exists; the create-or-
+-- reuse guard below covers the defensive case where Imageable attaches first.
+--
+-- onDraw: the image LAYER is rendered by the integrated `Renderer:draw` call
+-- (owned by the Themed behavior) which executes the renderer's `image` draw
+-- command using the config Imageable.onAttach wired. Imageable.onDraw is
+-- therefore a no-op for the draw call itself — there is no separate
+-- `_renderer:_drawImage` entry point; pixel emission lives in the integrated
+-- Renderer:draw command buffer. Splitting it out would require Renderer surgery
+-- with no behavioral gain (Renderer:draw already conditionally skips the image
+-- layer when no image is loaded).
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (`element._loadedImage`,
+--     `element._renderer._loadedImage`). The behavior instance is stateless.
+--   * saveState/restoreState persist `_loadedImage` across immediate-mode frames
+--     so the image renders even if the ImageCache is cleared between frames and
+--     so the renderer's loaded-image cache survives element recreation.
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Lua 5.4 removed the global `unpack`; mirror Element's alias.
+local unpack = table.unpack or unpack
+
+-- Resolve the Element class from an element instance (mirrors Clickable/Themed).
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- shouldAttach (class-level predicate, no element required)
+-- ----------------------------------------------------------------------------
+
+local function shouldAttach(props)
+  props = props or {}
+  return props.imagePath ~= nil or props.image ~= nil
+end
+
+-- ----------------------------------------------------------------------------
+-- Image callback helper (moved from Element._fireImageCallback).
+-- Fires a user-supplied image callback (onImageLoad/onImageError) under pcall,
+-- honoring the onXDeferred flag when `honorDeferred` is true, and emits a single
+-- EVT_002 warn on failure. The direct-`image` sync init path passes
+-- honorDeferred=false to preserve immediate firing (image is already loaded).
+-- ----------------------------------------------------------------------------
+
+local function fireImageCallback(element, callbackField, honorDeferred, ...)
+  local cb = element[callbackField]
+  if type(cb) ~= "function" then
+    return
+  end
+  local Element = ElementClass(element)
+  local argc = select("#", ...)
+  local args = { ... }
+  local function invoke()
+    local ok, err = pcall(cb, element, unpack(args, 1, argc))
+    if not ok then
+      Element._ErrorHandler:warn("Element", "EVT_002", {
+        callback = callbackField,
+        error = tostring(err),
+      })
+    end
+  end
+  if honorDeferred and element[callbackField .. "Deferred"] then
+    Element._Context.deferCallback(invoke)
+  else
+    invoke()
+  end
+end
+
+-- ----------------------------------------------------------------------------
+-- Deferred image loader (replaces Element:_loadImage).
+--
+-- Invoked by Element's deferred-method dispatcher via the instance closure that
+-- onAttach installs on `element._loadImage`. Loads the image from cache or disk
+-- (I/O), updates BOTH the element and renderer `_loadedImage` caches so the
+-- image draws after an async load, and fires the load/error callback (deferred,
+-- honoring onImageLoadDeferred / onImageErrorDeferred).
+-- ----------------------------------------------------------------------------
+
+local function loadImage(element)
+  if not element.imagePath or element.image then
+    return
+  end
+  local Element = ElementClass(element)
+  local loadedImage, err = Element._ImageCache.load(element.imagePath)
+  if loadedImage then
+    element._loadedImage = loadedImage
+    if element._renderer then
+      element._renderer._loadedImage = loadedImage
+    end
+    fireImageCallback(element, "onImageLoad", true, loadedImage)
+  else
+    fireImageCallback(element, "onImageError", true, err or "Unknown error")
+  end
+end
+
+-- ----------------------------------------------------------------------------
+-- reloadImage — recompute the loaded-image cache from the current image/imagePath.
+--
+-- This is the single entry point for (re)loading after either initial attach or
+-- a runtime property change (see Element._specialSetHandlers.imagePath/image,
+-- which call element:_reloadImage()). Precedence matches onAttach: a direct
+-- `image` wins over `imagePath`; `nil` for both clears the cache.
+--
+--   * direct image  → set _loadedImage immediately, fire onImageLoad SYNC (the
+--                     image is already loaded; honorDeferred=false preserves the
+--                     original synchronous init contract).
+--   * imagePath     → cache CHECK only (no I/O) so a cached image can draw this
+--                     frame, then defer the loader (_loadImage) for the actual
+--                     I/O + deferred callbacks. load bails if `image` is later set.
+--   * neither      → clear _loadedImage on both element + renderer.
+--
+-- Image value props (objectFit/imageOpacity/imageRepeat/imageTint/objectPosition)
+-- and imagePath/image themselves live on the ELEMENT as source of truth; the
+-- renderer reads them at draw time, so reloadImage does NOT mirror them onto the
+-- renderer — only the resolved _loadedImage cache is pushed.
+-- ----------------------------------------------------------------------------
+
+local function reloadImage(element)
+  local Element = ElementClass(element)
+  local renderer = element._renderer
+  if element.image then
+    element._loadedImage = element.image
+    if renderer then
+      renderer._loadedImage = element.image
+    end
+    fireImageCallback(element, "onImageLoad", false, element.image)
+  elseif element.imagePath then
+    -- Cache check (no I/O). Populate both caches immediately if cached so the
+    -- image can draw this frame without waiting for the deferred load.
+    local cached = Element._ImageCache.get(element.imagePath)
+    element._loadedImage = cached
+    if renderer then
+      renderer._loadedImage = cached
+    end
+    -- Kick off the deferred I/O load + callbacks (idempotent: loadImage bails
+    -- if image is set or imagePath is nil by the time it runs).
+    if element._loadImage then
+      element:_deferMethod("_loadImage")
+    end
+  else
+    element._loadedImage = nil
+    if renderer then
+      renderer._loadedImage = nil
+    end
+  end
+end
+
+-- ----------------------------------------------------------------------------
+-- onAttach — enrich the shared renderer with image config + kick off loading
+-- (formerly the image block of Element:_initImageAndRenderer).
+-- ----------------------------------------------------------------------------
+
+local function onAttach(element)
+  local Element = ElementClass(element)
+
+  -- Ensure the renderer exists (Thamed normally creates it; this create-or-reuse
+  -- guard is defensive for the Imageable-attaches-first ordering).
+  if not element._renderer then
+    element._renderer = Element._Renderer.new({
+      theme = element.theme,
+      scaleCorners = element.scaleCorners,
+      scalingAlgorithm = element.scalingAlgorithm,
+      contentBlur = element.contentBlur,
+      backdropBlur = element.backdropBlur,
+    }, Element._rendererDeps)
+  end
+
+  -- Install the (re)load hooks as instance methods so Element's
+  -- deferred-method dispatcher / setProperty special handlers can trigger a
+  -- reload without Element needing a behavior reference. This keeps Element
+  -- decoupled from the Imageable behavior (mirrors the stateless-behavior +
+  -- element-owned-state contract). Image value props and imagePath/image live
+  -- on the element as source of truth (read at draw time); only the resolved
+  -- _loadedImage cache is mirrored onto the renderer by reloadImage.
+  element._loadImage = function(el)
+    loadImage(el)
+  end
+  element._reloadImage = function(el)
+    reloadImage(el)
+  end
+
+  -- Initial load: compute _loadedImage + defer the I/O load.
+  reloadImage(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- onDraw — no-op (see file header: the image layer is rendered by the integrated
+-- Renderer:draw call owned by the Themed behavior, using the config wired here).
+-- ----------------------------------------------------------------------------
+
+-- ----------------------------------------------------------------------------
+-- saveState / restoreState — `_loadedImage` cache (for immediate-mode).
+-- ----------------------------------------------------------------------------
+
+local function saveState(element)
+  if element._loadedImage ~= nil then
+    return { _loadedImage = element._loadedImage }
+  end
+  return nil
+end
+
+local function restoreState(element, state)
+  if not state or state._loadedImage == nil then
+    return nil
+  end
+  local loadedImage = state._loadedImage
+  element._loadedImage = loadedImage
+  if element._renderer then
+    element._renderer._loadedImage = loadedImage
+  end
+  return nil
+end
+
+-- ----------------------------------------------------------------------------
+-- onDetach — release image-load callback closures so the element can be GC'd
+-- cleanly in immediate mode (formerly part of Element:_cleanup). The cached
+-- `_loadedImage` is reproduced on the next attach via the Imageable saveState
+-- -> restoreState cycle, so dropping the live references is always safe.
+-- ----------------------------------------------------------------------------
+
+local function onDetach(element)
+  element.onImageLoad = nil
+  element.onImageError = nil
+end
+
+-- ----------------------------------------------------------------------------
+-- Build the (stateless, shared, immutable) behavior instance.
+-- ----------------------------------------------------------------------------
+
+local Imageable = Behavior.new({
+  onAttach = onAttach,
+  onDetach = onDetach,
+  onUpdate = function() end,
+  onDraw = function() end,
+  saveState = saveState,
+  restoreState = restoreState,
+  shouldAttach = shouldAttach,
+})
+
+-- Expose the predicate at module level so callers/tests can reference it
+-- directly without an element instance (mirrors Behavior.shouldAttach /
+-- Clickable.shouldAttach). `loadImage` is NOT exposed on the (frozen) behavior
+-- instance; it is captured as a module-local upvalue by the onAttach closure that
+-- installs `element._loadImage`.
+Imageable.shouldAttach = shouldAttach
+
+return Imageable

libs/flexlove/modules/behaviors/Persistable.lua

@@ -0,0 +1,132 @@
+-- modules/behaviors/Persistable.lua
+--
+-- Concrete behavior: generic public-property persistence across the immediate-
+-- mode recreation cycle (behavior-mode-unification task 12).
+--
+-- Owns the ONE piece of Element save/restore state that is NOT subsystem state:
+-- the snapshot of an element's own public scalar fields (`text`, `display`,
+-- `opacity`, `x`, `width`, ...). Event-driven mutations to these fields (a
+-- release callback changing `text`, a toggle hiding a panel via `display =
+-- false`) must survive the per-frame Element recreation that defines immediate
+-- mode. Persistable captures them in `saveState` and reapplies them in
+-- `restoreState`, so the caller never branches on mode.
+--
+-- This behavior is the final home for the former `Element:saveState` `_props`
+-- block and the former `Element:restoreState` `_props` block (~20 LOC moved out
+-- of Element.lua). With it in place, `Element:saveState` / `Element:restoreState`
+-- collapse to a pure behavior-dispatch loop and Element owns zero property-
+-- extraction logic — every persisted slice is owned by exactly one behavior.
+--
+-- Attachment rule (shouldAttach): every element. Persistable attaches
+-- unconditionally (mirrors the pre-refactor invariant that every element's
+-- public scalar props were scanned). The actual snapshot is mode-gated inside
+-- `saveState` (immediate-mode-only, matching the legacy contract); in retained
+-- mode `saveState` returns nil and `restoreState` is a no-op unless a snapshot
+-- is explicitly passed.
+--
+-- Registry ordering: Persistable is intentionally placed LAST in the behavior
+-- registry. `restoreState` applies `_props` AFTER every other behavior has
+-- hydrated its subsystem state, so a persisted public-prop mutation (e.g.
+-- `text = "mutated"`) overrides the freshly-restored TextEditor/Select state —
+-- preserving the legacy restore ordering (behaviors first, `_props` tail).
+--
+-- State ownership (per the locked Behavior contract):
+--   * The persisted props live ON the element (they ARE the element's public
+--     fields). The behavior instance is stateless + immutable and shared.
+--   * The snapshot is returned under the `_props` key (prefixed with `_` so
+--     the public-prop scan itself skips it — avoiding self-recursion).
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance (mirrors Clickable /
+-- Themed). Element instances are created via `setmetatable({}, Element)`, so
+-- their metatable IS the Element class — giving access to Element._StateManager
+-- without threading deps through the hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ============================================================================
+-- shouldAttach (class-level predicate, no element required)
+-- ============================================================================
+
+-- Every element's public scalar props are persistable, so this behavior
+-- attaches unconditionally. The mode gate lives inside saveState (it needs the
+-- runtime mode, which is only available with an element via StateManager).
+local function shouldAttach()
+  return true
+end
+
+-- ============================================================================
+-- saveState — snapshot public scalar fields (immediate-mode-only).
+-- ============================================================================
+
+-- Mirrors the former `Element:saveState` `_props` block exactly:
+--   * Only string keys NOT prefixed with `_` (so internal fields like
+--     `_renderer`, `_themeState`, `_initProps` are excluded).
+--   * Only scalar values (numbers, strings, booleans); tables and functions
+--     are excluded (children, padding, onEvent, ...).
+-- Returns `{ _props = {...} }` when there is at least one persistable prop and
+-- the element is in immediate mode; nil otherwise (retained mode no-op —
+-- state lives on the element directly there, so nothing to snapshot).
+local function saveState(element)
+  local Element = ElementClass(element)
+  if not Element._StateManager.isImmediateMode() then
+    return nil
+  end
+  local props = {}
+  for k, v in pairs(element) do
+    if type(k) == "string" and k:sub(1, 1) ~= "_" and type(v) ~= "table" and type(v) ~= "function" then
+      props[k] = v
+    end
+  end
+  if next(props) then
+    return { _props = props }
+  end
+  return nil
+end
+
+-- ============================================================================
+-- restoreState — reapply the persisted public-prop snapshot onto a fresh
+-- element (mode-agnostic; only fires when a `_props` slice is present).
+-- ============================================================================
+
+-- Applies persisted mutations on top of whatever the constructor + other
+-- behaviors already set, so event-driven changes from the previous frame
+-- override the declarative props of the recreated element. Runs last in the
+-- behavior dispatch (Persistable is the registry tail) to preserve the legacy
+-- restore ordering (subsystem restore first, `_props` override last).
+local function restoreState(element, state)
+  if not state or not state._props then
+    return
+  end
+  for k, v in pairs(state._props) do
+    element[k] = v
+  end
+end
+
+-- ============================================================================
+-- onAttach / onUpdate / onDraw / onDetach — no-ops.
+-- ============================================================================
+
+-- Persistable owns no subsystem and allocates no per-element state (the
+-- "state" it persists IS the element's own fields). The lifecycle is purely
+-- save/restore.
+
+-- ============================================================================
+-- Build the (stateless, shared, immutable) behavior instance.
+-- ============================================================================
+
+local Persistable = Behavior.new({
+  saveState = saveState,
+  restoreState = restoreState,
+  shouldAttach = shouldAttach,
+})
+
+-- Expose the predicate at module level so callers/tests can reference it
+-- directly without an element instance (mirrors Behavior.shouldAttach /
+-- Clickable.shouldAttach).
+Persistable.shouldAttach = shouldAttach
+
+return Persistable

libs/flexlove/modules/behaviors/Scrollable.lua

@@ -0,0 +1,264 @@
+-- modules/behaviors/Scrollable.lua
+--
+-- Concrete behavior: ScrollManager lifecycle (creation + immediate-mode
+-- scrollbar interaction-state restore).
+--
+-- Scrollable owns the per-element ScrollManager instance — the subsystem that
+-- manages overflow detection, scrollbar geometry, scroll position, and scrollbar
+-- drag/hover interaction. It is the behavior-mode-unification replacement for
+-- the former `Element:_initScrollManager` phase (~84 LOC) of Element.new
+-- (behavior-mode-unification task 03 / landed as part of the task 08 capstone).
+--
+-- Attachment rule (shouldAttach): an element owns a ScrollManager exactly when
+-- it declares an `overflow`, `overflowX`, or `overflowY` prop — mirroring the
+-- legacy `if props.overflow or props.overflowX or props.overflowY then` guard
+-- in `Element:_initScrollManager`. The ScrollManager is created and its
+-- normalized fields are exposed back onto the element (so the Renderer /
+-- ScrollManager delegates read `element.overflow` / `element.scrollbarWidth`
+-- etc.) exactly as the legacy inline phase did.
+--
+-- Why onAttach reads `element._initProps` (not element fields): the scrollbar
+-- configuration props (scrollbarWidth / scrollbarColor / scrollSpeed /
+-- scrollbarPlacement / scrollbarBalance / invertScroll / smoothScrollEnabled /
+-- scrollBarStyle / scrollbarKnobOffset / hideScrollbars / scrollbarRadius /
+-- scrollbarPadding / scrollbarTrackColor / _scrollX / _scrollY) are listed in
+-- SPECIAL_PROPS and therefore NOT bound onto the element by the schema-driven
+-- `_applyProps` loop — they are consumed only by the ScrollManager constructor.
+-- The locked behavior hook signature is `(element, ...)` with no props arg, so
+-- the original construction props are stashed on the element as `_initProps` by
+-- `Element:_construct` and read back here. (`overflow` / `overflowX` /
+-- `overflowY` ARE bound onto the element by `_applyProps` so that
+-- `Element:addChild`'s scroll-container auto-size guard sees them during
+-- declarative-children processing in `_finalizeConstruction`, which runs BEFORE
+-- this onAttach; onAttach then overwrites them with the ScrollManager's
+-- normalized values, matching the legacy field-exposure order.)
+--
+-- onUpdate / onDraw / saveState / restoreState are deferred to the
+-- behavior-driven update/draw tasks (09 / 12): the ScrollManager update,
+-- interaction, scrollbar drawing, and state save/restore currently stay inline
+-- in `Element:update` / `Element:draw` / `Element:saveState` /
+-- `Element:restoreState` (delegated through the ScrollManager API bound in
+-- `Element.init`). Those inline call sites are NOT behavioral `if` branches —
+-- they are unconditional 1-line delegates — so leaving them in Element does not
+-- regress the behavior-dispatch goals of tasks 09/12; task 09 will fold them
+-- into Scrollable hooks.
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (`element._scrollManager`,
+--     `element.overflow`, `element._scrollX`, `element._scrollbarDragging`, ...).
+--   * The behavior instance is stateless + immutable and shared across elements.
+--   * Element-class-level dependencies (`Element._ScrollManager`,
+--     `Element._scrollManagerDeps`, `Element._Context`, `Element._StateManager`)
+--     are resolved from the owning element's metatable (the Element class set by
+--     `Element:_construct`).
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance.
+-- `setmetatable({}, Element)` in `_construct` makes the instance metatable BE
+-- the Element class, so this yields Element._ScrollManager,
+-- Element._scrollManagerDeps, Element._Context, Element._StateManager without
+-- threading deps through the hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- shouldAttach (class-level predicate, no element required)
+-- ----------------------------------------------------------------------------
+
+-- Mirrors the legacy `if props.overflow or props.overflowX or props.overflowY`
+-- guard. Uses `~= nil` (rather than truthiness) so that an explicit
+-- `overflow = false` / `overflow = ""` does not spuriously attach — though in
+-- practice overflow values are always strings or unset, matching the predicate
+-- semantics of the other behaviors (Clickable / TextEditable / Selectable).
+local function shouldAttach(props)
+  props = props or {}
+  return props.overflow ~= nil or props.overflowX ~= nil or props.overflowY ~= nil
+end
+
+-- ----------------------------------------------------------------------------
+-- onAttach — create the ScrollManager + expose its fields + restore immediate-
+-- mode scrollbar interaction state (formerly Element:_initScrollManager).
+-- ----------------------------------------------------------------------------
+
+local function onAttach(element)
+  local Element = ElementClass(element)
+  -- Construction props are stashed on the element by _construct (the scrollbar
+  -- config props are SPECIAL_PROPS and not bound as element fields).
+  local props = element._initProps or {}
+
+  element._scrollManager = Element._ScrollManager.new({
+    overflow = props.overflow,
+    overflowX = props.overflowX,
+    overflowY = props.overflowY,
+    scrollbarWidth = props.scrollbarWidth,
+    scrollbarColor = props.scrollbarColor,
+    scrollbarTrackColor = props.scrollbarTrackColor,
+    scrollbarRadius = props.scrollbarRadius,
+    scrollbarPadding = props.scrollbarPadding,
+    scrollSpeed = props.scrollSpeed,
+    invertScroll = props.invertScroll,
+    smoothScrollEnabled = props.smoothScrollEnabled,
+    scrollBarStyle = props.scrollBarStyle,
+    scrollbarKnobOffset = props.scrollbarKnobOffset,
+    hideScrollbars = props.hideScrollbars,
+    scrollbarPlacement = props.scrollbarPlacement,
+    scrollbarBalance = props.scrollbarBalance,
+    _scrollX = props._scrollX,
+    _scrollY = props._scrollY,
+  }, Element._scrollManagerDeps)
+
+  -- Expose ScrollManager properties for backward compatibility (Renderer access).
+  local sm = element._scrollManager
+  element.overflow = sm.overflow
+  element.overflowX = sm.overflowX
+  element.overflowY = sm.overflowY
+  element.scrollbarWidth = sm.scrollbarWidth
+  element.scrollbarColor = sm.scrollbarColor
+  element.scrollbarTrackColor = sm.scrollbarTrackColor
+  element.scrollbarRadius = sm.scrollbarRadius
+  element.scrollbarPadding = sm.scrollbarPadding
+  element.scrollSpeed = sm.scrollSpeed
+  element.invertScroll = sm.invertScroll
+  element.scrollBarStyle = sm.scrollBarStyle
+  element.scrollbarKnobOffset = sm.scrollbarKnobOffset
+  element.hideScrollbars = sm.hideScrollbars
+  element.scrollbarPlacement = sm.scrollbarPlacement
+  element.scrollbarBalance = sm.scrollbarBalance
+
+  -- Initialize state properties (will be synced from ScrollManager).
+  element._overflowX = false
+  element._overflowY = false
+  element._contentWidth = 0
+  element._contentHeight = 0
+  element._scrollX = 0
+  element._scrollY = 0
+  element._maxScrollX = 0
+  element._maxScrollY = 0
+  element._scrollbarHoveredVertical = false
+  element._scrollbarHoveredHorizontal = false
+  element._scrollbarDragging = false
+  element._hoveredScrollbar = nil
+  element._scrollbarDragOffset = 0
+
+  -- Restore scrollbar state from StateManager in immediate mode (must happen
+  -- before layout). Mirrors the legacy _initScrollManager restore block.
+  -- Mode-aware via Context.isImmediateMode (behavior-mode-unification task 11).
+  if Element._Context.isImmediateMode() and element._stateId and element._stateId ~= "" then
+    local state = Element._StateManager.getState(element._stateId)
+    if state and state.scrollManager then
+      element._scrollbarHoveredVertical = state.scrollManager._scrollbarHoveredVertical or false
+      element._scrollbarHoveredHorizontal = state.scrollManager._scrollbarHoveredHorizontal or false
+      element._scrollbarDragging = state.scrollManager._scrollbarDragging or false
+      element._hoveredScrollbar = state.scrollManager._hoveredScrollbar
+      element._scrollbarDragOffset = state.scrollManager._scrollbarDragOffset or 0
+
+      -- Apply to ScrollManager immediately.
+      sm._scrollbarHoveredVertical = element._scrollbarHoveredVertical
+      sm._scrollbarHoveredHorizontal = element._scrollbarHoveredHorizontal
+      sm._scrollbarDragging = element._scrollbarDragging
+      sm._hoveredScrollbar = element._hoveredScrollbar
+      sm._scrollbarDragOffset = element._scrollbarDragOffset
+
+      -- Restore drag start positions for relative movement tracking.
+      sm._dragStartMouseX = state.scrollManager._dragStartMouseX or 0
+      sm._dragStartMouseY = state.scrollManager._dragStartMouseY or 0
+      sm._dragStartScrollX = state.scrollManager._dragStartScrollX or 0
+      sm._dragStartScrollY = state.scrollManager._dragStartScrollY or 0
+    end
+  end
+end
+
+-- --------------------------------------------------------------------------
+-- onUpdate — scroll-position momentum + scrollbar hover/drag/press interaction
+-- (formerly the inline ScrollManager blocks in Element:update).
+-- Runs BEFORE Clickable.onUpdate in the registry so the scrollbar press flag
+-- is set before Clickable's EventHandler processes mouse events.
+-- --------------------------------------------------------------------------
+
+local function onUpdate(element, dt)
+  local Element = ElementClass(element)
+  local sm = element._scrollManager
+  if not sm then
+    return
+  end
+  -- Restore scrollbar interaction state from StateManager in immediate mode
+  -- (no-op outside immediate mode / when no state is stored).
+  Element._ScrollManager.restoreImmediateState(element)
+
+  -- Smooth-scroll / momentum interpolation.
+  sm:update(dt)
+  element:_syncScrollManagerState()
+
+  -- Scrollbar hover / drag / press interaction. Captures the mouse here so the
+  -- interaction state is consistent across the rest of the frame's behaviors.
+  local mx, my = love.mouse.getPosition()
+  Element._ScrollManager.updateInteraction(element, mx, my)
+end
+
+-- --------------------------------------------------------------------------
+-- onDraw — scrollbar rendering (post-children overlay). Marked
+-- `drawLayer = "overlay"` so Element:draw dispatches it AFTER children, so
+-- scrollbars paint on top of clipped child content and without parent clipping.
+-- --------------------------------------------------------------------------
+
+local function onDraw(element, _ctx)
+  local overflowX = element.overflowX or element.overflow
+  local overflowY = element.overflowY or element.overflow
+  if overflowX ~= "scroll" and overflowX ~= "auto" and overflowY ~= "scroll" and overflowY ~= "auto" then
+    return
+  end
+  local scrollbarDims = element:_calculateScrollbarDimensions()
+  if not (scrollbarDims.vertical.visible or scrollbarDims.horizontal.visible) then
+    return
+  end
+  -- Clear any parent scissor clipping before drawing scrollbars so they render
+  -- fully visible (scrollbars must not be clipped by ancestor overflow).
+  love.graphics.setScissor()
+  element._renderer:drawScrollbars(element, element.x, element.y, element.width, element.height, scrollbarDims)
+end
+
+-- --------------------------------------------------------------------------
+-- saveState / restoreState — ScrollManager state snapshot for immediate-mode
+-- recreation (formerly the inline blocks in Element:saveState/
+-- Element:restoreState). Returns a table merged under the `scrollManager` key
+-- by Element:saveState's behavior loop, mirroring the legacy contract.
+-- --------------------------------------------------------------------------
+
+local function saveState(element)
+  local sm = element._scrollManager
+  if not sm then
+    return nil
+  end
+  return { scrollManager = sm:getState() }
+end
+
+local function restoreState(element, state)
+  if not state then
+    return
+  end
+  local sm = element._scrollManager
+  local smState = state.scrollManager
+  if sm and smState then
+    sm:setState(smState)
+  end
+end
+
+local Scrollable = Behavior.new({
+  onAttach = onAttach,
+  onDetach = function() end,
+  onUpdate = onUpdate,
+  onDraw = onDraw,
+  saveState = saveState,
+  restoreState = restoreState,
+  drawLayer = "overlay",
+})
+
+-- Expose the predicate at module level so callers/tests can reference it
+-- directly without an element instance (mirrors Clickable.shouldAttach /
+-- Selectable.shouldAttach).
+Scrollable.shouldAttach = shouldAttach
+
+return Scrollable

libs/flexlove/modules/behaviors/Selectable.lua

@@ -0,0 +1,206 @@
+-- modules/behaviors/Selectable.lua
+--
+-- Concrete behavior: Select state-machine lifecycle for dropdown-style
+-- select groups. Owns the per-element Select subsystem initialization, the
+-- managed-frame layout sync each frame, and select save/restore across the
+-- immediate-mode recreation cycle.
+--
+-- This behavior consolidates the legacy `if self._selectState` / `if
+-- self.selectOption` branches that previously lived inside Element.lua:
+--
+--   * Select subsystem init (formerly Element:_initSubSystems lines ~810-825 —
+--     `Select.initSelectParent` / `Select.initSelectOption`).
+--   * Managed-frame adoption (formerly Element:_initPositioning lines ~1700-
+--     1702 — `Select.adoptSelectFrame`).
+--   * Per-frame frame-state sync (formerly Element:update line ~2747 —
+--     `Select.ensureFrameState`).
+--   * Save/restore of select open/value/label (formerly the `select` branch of
+--     Element:saveState / Element:restoreState).
+--
+-- Element retains `self._selectState` and `self.selectOption` for backward-
+-- compat field access; runtime state lives ON THE ELEMENT. The behavior itself
+-- is stateless + immutable (a single shared instance attaches to every
+-- selectable element).
+--
+-- The 20 Element select-API delegate methods (openSelect, closeSelect,
+-- toggleSelect, isSelectOpen, getSelectValue, setSelectValue, ...) stay as
+-- 1-line forwarders into the Select module — the behavior owns the
+-- *lifecycle* (attach / update / save / restore / detach), not the API
+-- surface (per task 05 spec notes).
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (self._selectState,
+--     self.selectOption, self._selectParentElement, ...).
+--   * The behavior instance is stateless + immutable and shared across elements.
+--   * Element-class-level dependencies are resolved via `getmetatable(element)`
+--     (which IS the Element class set by Element._construct), so the hook
+--     signature stays exactly `(element, ...)` with no DI parameters.
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance.
+-- `setmetatable({}, Element)` in `_construct` makes the instance metatable BE
+-- the Element class, so this yields Element._Select, Element._Context,
+-- Element._StateManager, etc. without threading deps through the hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ============================================================================
+-- shouldAttach (class-level predicate, no element required)
+-- ============================================================================
+
+-- Mirrors the cases that previously caused Element to initialize a Select
+-- subsystem. An element owns select state exactly when it declares a
+-- `selectParent` config (the dropdown trigger) or a `selectOption` config (an
+-- option inside a dropdown). Checking the props (rather than the runtime
+-- `_selectState`) lets shouldAttach run before onAttach initializes the
+-- subsystem, matching the auto-attach contract established by Clickable /
+-- TextEditable.
+local function shouldAttach(props)
+  props = props or {}
+  return type(props.selectParent) == "table" or type(props.selectOption) == "table"
+end
+
+-- ============================================================================
+-- onAttach — initialize the Select subsystem (formerly Element:_initSubSystems
+-- lines ~810-825) and adopt the managed frame (formerly Element:_initPositioning
+-- lines ~1700-1702).
+-- ============================================================================
+
+local function onAttach(element)
+  local Element = ElementClass(element)
+
+  -- Initialize the appropriate select role. Mirrors the legacy _initSubSystems
+  -- block exactly: selectParent → initSelectParent (sets _selectState +
+  -- immediate-mode restore from StateManager); selectOption → initSelectOption
+  -- (sets the option value/label/disabled).
+  if type(element.selectParent) == "table" then
+    Element._Select.initSelectParent(element, element.selectParent)
+  end
+
+  if type(element.selectOption) == "table" then
+    Element._Select.initSelectOption(element, element.selectOption)
+  end
+
+  -- Adopt the managed dropdown frame. This was formerly the tail of
+  -- _initPositioning (after the select parent's own addChild). It creates the
+  -- select anchor, reparents the frame under it, and syncs visibility. Moving
+  -- it here is safe because onAttach runs after _initPositioning: the parent's
+  -- own positioning is finalized, so the anchor's geometry can be computed.
+  if element._selectState and type(element.selectParent) == "table" and element.selectParent.selectFrame ~= nil then
+    Element._Select.adoptSelectFrame(element, element.selectParent.selectFrame)
+  end
+
+  -- Backfill option registration for children added BEFORE this behavior
+  -- attached. The auto-attach pass runs at the very end of Element.new
+  -- (after _finalizeConstruction, which processes declarative `children`).
+  -- Declarative select-option children are addChild'd to this element during
+  -- _finalizeConstruction — at that point _selectState did not yet exist (this
+  -- onAttach had not run), so their registerWithSelectParent call walked the
+  -- parent chain, found no _selectState, and returned early. Re-scan now that
+  -- _selectState is initialized so these options are registered + reparented
+  -- into the managed frame exactly like runtime-added options.
+  -- (registerWithSelectParent is idempotent — it skips options already
+  -- registered — so this is a no-op for children added after _selectState was
+  -- set, e.g. the common `FlexLove.new({ parent = sp, selectOption = {...} })`
+  -- pattern.)
+  if element._selectState then
+    for _, child in ipairs(element.children) do
+      if child.selectOption then
+        Element._Select.registerWithSelectParent(child)
+        Element._Select.attachOptionToManagedFrame(child)
+      end
+    end
+  end
+end
+
+local function onDetach(element)
+  -- Clear select-managed fields so the element can be GC'd cleanly in immediate
+  -- mode (formerly part of Element:_cleanup). This mirrors the select-clearing
+  -- block that lived in Element:_cleanup; Element:destroy separately routes
+  -- through Select.cleanupDestroy for full teardown (idempotent with this).
+  if element.selectParent then
+    element.selectParent.onChange = nil
+  end
+  element._selectState = nil
+  element._managedSelectOwner = nil
+  element._managedSelectFrame = nil
+  element._managedSelectAnchor = nil
+  element._managedSelectBaseOpacity = nil
+  element._managedSelectBaseVisibility = nil
+  element._managedSelectBaseDisabled = nil
+end
+
+-- ============================================================================
+-- onUpdate — per-frame managed-frame layout sync (formerly Element:update
+-- line ~2747 — `Select.ensureFrameState`).
+-- ============================================================================
+
+local function onUpdate(element, dt)
+  local Element = ElementClass(element)
+  Element._Select.ensureFrameState(element)
+end
+
+-- ============================================================================
+-- onDraw — no-op.
+-- ============================================================================
+
+-- Select rendering is driven by the managed frame / anchor elements themselves
+-- (visibility synced by Select.syncManagedFrameVisibility), not by the select
+-- parent's draw path. The parent's own pixels are the theme/renderer's job.
+local function onDraw() end
+
+-- ============================================================================
+-- saveState / restoreState — select open/value/label (formerly the `select`
+-- branch of Element:saveState / Element:restoreState).
+-- ============================================================================
+
+-- Returns a snapshot under the `select` key to match the legacy immediate-mode
+-- restoreState contract (Element:restoreState looked up state.select). The
+-- behavior-dispatch loop merges behavior snapshots into the top-level state
+-- table, so returning { select = ... } slots in identically to the old inline
+-- `state.select = selectState` assignment.
+local function saveState(element)
+  local Element = ElementClass(element)
+  local selectState = Element._Select.saveState(element)
+  if selectState then
+    return { select = selectState }
+  end
+  return nil
+end
+
+-- Consumes the previously-saved snapshot keyed under `select`. The behavior-
+-- dispatch loop passes the FULL top-level state table; this hook reads only
+-- its own `state.select` slice, mirroring the legacy `if state.select then`
+-- guard in Element:restoreState.
+local function restoreState(element, state)
+  if not state then
+    return
+  end
+  local Element = ElementClass(element)
+  if state.select then
+    Element._Select.restoreState(element, state.select)
+  end
+end
+
+-- ============================================================================
+-- Build the (stateless, shared, immutable) behavior instance.
+-- ============================================================================
+
+local Selectable = Behavior.new({
+  onAttach = onAttach,
+  onDetach = onDetach,
+  onUpdate = onUpdate,
+  onDraw = onDraw,
+  saveState = saveState,
+  restoreState = restoreState,
+  shouldAttach = shouldAttach,
+})
+
+-- Expose the predicate at module level so callers/tests can reference it
+-- directly without an element instance (mirrors Behavior.shouldAttach).
+Selectable.shouldAttach = shouldAttach
+
+return Selectable

libs/flexlove/modules/behaviors/TextEditable.lua

@@ -0,0 +1,576 @@
+-- modules/behaviors/TextEditable.lua
+--
+-- Concrete behavior: TextEditor subsystem ownership — text editing, cursor
+-- management, text selection, text-related input handling, and text-editor
+-- state save/restore.
+--
+-- This behavior consolidates the legacy `if self._textEditor` nil-guard
+-- patterns that previously lived inside Element.lua:
+--
+--   * TextEditor creation + immediate-mode state restore (formerly
+--     Element:_initSubSystems lines ~813-830 — the `if self.editable then
+--     self._textEditor = Element._TextEditor.new {...}` block).
+--   * Cursor-blink update (formerly Element:update line ~2810 —
+--     `if self._textEditor then self._textEditor:update(self, dt) end`).
+--   * The 27 text-editor delegate methods (formerly Element:setText /
+--     getText / setCursorPosition / setSelection / focus / textinput /
+--     keypressed / _handleTextClick / _handleTextDrag / ...). Each was a 3-line
+--     nil-guard stub (check `_textEditor`, forward call, end). They are now
+--     module-level functions on this behavior; Element retains only 1-line
+--     forwarders that route through `Element._TextEditable.<fn>(self, ...)`.
+--   * Text-editor state save/restore (formerly the textEditor branch of
+--     Element:saveState / Element:restoreState), including the cursor/selection
+--     field sync and the text-selection drag-tracking fields
+--     (`_mouseDownPosition` / `_textDragOccurred`).
+--
+-- Element retains the `self._textEditor` field for backward-compat field
+-- access (Renderer:drawText reads it directly for cursor/selection rendering);
+-- runtime state lives ON THE ELEMENT. The behavior itself is stateless +
+-- immutable + shared across elements.
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (`self._textEditor`,
+--     `self._mouseDownPosition`, `self._textDragOccurred`). The behavior
+--     instance is stateless + immutable and shared across all editable
+--     elements.
+--   * Element-class-level dependencies are resolved via `getmetatable(element)`
+--     (which IS the Element class set by Element._construct), so the hook
+--     signature stays exactly `(element, ...)` with no DI parameters.
+--
+-- onDraw is a no-op: text/cursor/selection rendering stays in the Renderer's
+-- command buffer (Layer 4 "text"), driven by the Thamed behavior's single
+-- `Renderer:draw` call. The Renderer's `drawText` already reads
+-- `element._textEditor` for cursor/selection, so TextEditable OWNS the
+-- subsystem that drawText consumes, but the draw dispatch stays in the
+-- renderer to preserve the unified transform/scissor command-buffer ordering
+-- (mirrors Selectable.onDraw's no-op precedent, where rendering is owned by a
+-- different layer). Hoisting drawText into this behavior's onDraw would
+-- double-render text, since the Renderer command buffer already emits a "text"
+-- layer for every element.
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance (mirrors Clickable /
+-- Selectable). `setmetatable({}, Element)` in `_construct` makes the instance
+-- metatable BE the Element class, so this yields Element._TextEditor,
+-- Element._textEditorDeps, Element._Context, Element._StateManager, etc.
+-- without threading deps through the hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ============================================================================
+-- shouldAttach (class-level predicate, no element required)
+-- ============================================================================
+
+-- Mirrors the spec predicate: attach when the element is text-editable OR
+-- carries text content. onAttach only ALLOCATES a TextEditor when
+-- `element.editable` is true (preserving the pre-refactor creation invariant
+-- "TextEditor created iff editable"), so non-editable text labels attach the
+-- behavior but allocate no TextEditor — their onUpdate/onDraw/saveState are
+-- nil-guarded no-ops, and the Element forwarders route them through the
+-- non-editable branch of each delegate function (reads/writes `element.text`
+-- directly). This keeps shouldAttach faithful to the spec while preserving
+-- exact pre-refactor allocation behavior.
+local function shouldAttach(props)
+  props = props or {}
+  return props.editable == true or props.text ~= nil
+end
+
+-- ============================================================================
+-- onAttach — create the TextEditor (formerly Element:_initSubSystems lines
+-- ~813-830) and restore immediate-mode TextEditor state.
+-- ============================================================================
+
+local function onAttach(element)
+  local Element = ElementClass(element)
+
+  -- Only editable elements own a TextEditor. Preserves the exact pre-refactor
+  -- creation guard (`if self.editable then ... end`) — non-editable text
+  -- elements attach the behavior (so their forwarders route through a single
+  -- code path) but allocate no TextEditor.
+  if not element.editable then
+    return
+  end
+
+  -- Config is sourced from element fields (bound by _applyProps / _initVisualState
+  -- before _attachBehaviors runs at the tail of Element.new) — NOT from raw
+  -- props. The callbacks (onFocus/onBlur/onTextInput/onTextChange/onEnter) are
+  -- schema-bound element fields by this point, and `element.text` is set by
+  -- _initVisualState, so no `props` reference is needed here (the hook
+  -- signature is `(element)`).
+  element._textEditor = Element._TextEditor.new({
+    editable = element.editable,
+    multiline = element.multiline,
+    passwordMode = element.passwordMode,
+    textWrap = element.textWrap,
+    maxLines = element.maxLines,
+    maxLength = element.maxLength,
+    placeholder = element.placeholder,
+    inputType = element.inputType,
+    textOverflow = element.textOverflow,
+    scrollable = element.scrollable,
+    autoGrow = element.autoGrow,
+    selectOnFocus = element.selectOnFocus,
+    cursorColor = element.cursorColor,
+    selectionColor = element.selectionColor,
+    cursorBlinkRate = element.cursorBlinkRate,
+    text = element.text or "",
+    onFocus = element.onFocus,
+    onBlur = element.onBlur,
+    onTextInput = element.onTextInput,
+    onTextChange = element.onTextChange,
+    onEnter = element.onEnter,
+  }, Element._textEditorDeps)
+
+  -- Restore TextEditor state from StateManager in immediate mode. Mirrors the
+  -- legacy _initSubSystems immediate-mode restore. Safe to run here (after
+  -- _construct registered the element with StateManager) — the StateManager
+  -- lookup is sparse and returns nil for a fresh element. Mode-aware via
+  -- Context.isImmediateMode (behavior-mode-unification task 11).
+  if Element._Context.isImmediateMode() and element._stateId and element._stateId ~= "" then
+    local state = Element._StateManager.getState(element._stateId)
+    if state and state.textEditor then
+      element._textEditor:setState(state.textEditor, element)
+    end
+  end
+end
+
+local function onDetach(element)
+  -- Clear text-input callback closures read by TextEditor / KeyboardNavigation
+  -- so the element's closure references can be collected in immediate mode
+  -- (formerly part of Element:_cleanup). The TextEditor instance itself is
+  -- INTENTIONALLY kept: Element:_cleanup preserves element structure for
+  -- inspection (released when the element is GC'd).
+  element.onTextInput = nil
+  element.onTextChange = nil
+  element.onEnter = nil
+end
+
+-- ============================================================================
+-- onUpdate — cursor-blink animation (formerly Element:update line ~2810).
+-- ============================================================================
+
+-- Drives TextEditor:update (cursor blink + blink-pause timer). Guarded on
+-- `element._textEditor` because non-editable text elements attach this
+-- behavior (per shouldAttach) but own no TextEditor. Element:update contains
+-- zero text-editor references — the dispatch loop calls this hook.
+local function onUpdate(element, dt)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:update(element, dt)
+  end
+end
+
+-- ============================================================================
+-- onDraw — no-op (see file header: text rendering stays in the Renderer
+-- command buffer driven by the Thamed behavior's Renderer:draw call).
+-- ============================================================================
+
+local function onDraw() end
+
+-- ============================================================================
+-- saveState / restoreState — TextEditor state + text-selection drag
+-- tracking (formerly the textEditor branch of Element:saveState /
+-- Element:restoreState, including the _mouseDownPosition / _textDragOccurred
+-- fields).
+-- ============================================================================
+
+-- Returns a snapshot under the `textEditor` key to match the legacy immediate-
+-- mode restoreState contract (Element:restoreState looked up state.textEditor).
+-- The behavior-dispatch loop in Element:saveState merges behavior snapshots
+-- into the top-level state table, so returning { textEditor = ... } slots in
+-- identically to the old inline `state.textEditor = self._textEditor:getState()`
+-- assignment. The drag-tracking fields are merged at the top level too
+-- (matching the legacy `state._mouseDownPosition` / `state._textDragOccurred`
+-- assignments) since they are text-selection state.
+local function saveState(element)
+  local textEditor = element._textEditor
+  if not textEditor then
+    -- Non-editable text element: still persist drag-tracking fields if set
+    -- (they are only ever set for editable elements, but persist defensively).
+    local hasDragState = element._mouseDownPosition ~= nil or element._textDragOccurred ~= nil
+    if not hasDragState then
+      return nil
+    end
+    local snapshot = {}
+    if element._mouseDownPosition ~= nil then
+      snapshot._mouseDownPosition = element._mouseDownPosition
+    end
+    if element._textDragOccurred ~= nil then
+      snapshot._textDragOccurred = element._textDragOccurred
+    end
+    return snapshot
+  end
+
+  local snapshot = { textEditor = textEditor:getState() }
+  if element._mouseDownPosition ~= nil then
+    snapshot._mouseDownPosition = element._mouseDownPosition
+  end
+  if element._textDragOccurred ~= nil then
+    snapshot._textDragOccurred = element._textDragOccurred
+  end
+  return snapshot
+end
+
+-- Consumes the previously-saved snapshot keyed under `textEditor` plus the
+-- drag-tracking fields. The behavior-dispatch loop passes the FULL top-level
+-- state table; this hook reads only its own slices, mirroring the legacy
+-- `if self._textEditor and state.textEditor then ... end` guard.
+local function restoreState(element, state)
+  if not state then
+    return
+  end
+  local textEditor = element._textEditor
+  if textEditor and state.textEditor then
+    textEditor:setState(state.textEditor, element)
+    -- Sync TextEditor's focus/cursor/selection state to Element for theme
+    -- management (mirrors the legacy restoreState field sync).
+    element._focused = textEditor._focused
+    element._cursorPosition = textEditor._cursorPosition
+    element._selectionStart = textEditor._selectionStart
+    element._selectionEnd = textEditor._selectionEnd
+    element._textBuffer = textEditor._textBuffer
+  end
+
+  -- Restore drag-tracking state for text selection (top-level keys).
+  if state._mouseDownPosition ~= nil then
+    element._mouseDownPosition = state._mouseDownPosition
+  end
+  if state._textDragOccurred ~= nil then
+    element._textDragOccurred = state._textDragOccurred
+  end
+end
+
+-- ============================================================================
+-- Text-editor delegate functions.
+--
+-- These are the module-level implementations of the 27 text-editor delegate
+-- methods that previously lived on Element. Each mirrors the pre-refactor
+-- Element method body VERBATIM (with `self` → `element`), including the
+-- `element._textEditor` nil-guard: the guard is required because (a) non-
+-- editable text elements attach this behavior (per shouldAttach) but own no
+-- TextEditor, and (b) Element forwards these methods BEFORE onAttach has run
+-- (e.g. an `onCreate` callback firing during _finalizeConstruction, which
+-- runs before _attachBehaviors). The nil-guards live in THIS file (not in
+-- Element.lua), so the Element.lua `if self._textEditor` count drops to 0.
+--
+-- Element retains 1-line forwarders: `Element.setText = function(self, text)
+-- return Element._TextEditable.setText(self, text) end` (etc.), so external
+-- callers (EventHandler, KeyboardNavigation, game UI) keep working unchanged.
+--
+-- The TextEditor API is mixed: most methods take the element as first arg
+-- (`te:method(element, ...)` — "passesSelf"); a few getters omit it
+-- (`te:method()`). The delegation contract is pinned by
+-- subsystem_delegation_test.lua, so this mapping must match TextEditor's
+-- method signatures exactly.
+-- ============================================================================
+
+-- --- Cursor management (passesSelf = element forwarded) ------------------
+
+local function setCursorPosition(element, position)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:setCursorPosition(element, position)
+  end
+end
+
+local function getCursorPosition(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    return textEditor:getCursorPosition()
+  end
+  return 0
+end
+
+local function moveCursorBy(element, delta)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorBy(element, delta)
+  end
+end
+
+local function moveCursorToStart(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorToStart(element)
+  end
+end
+
+local function moveCursorToEnd(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorToEnd(element)
+  end
+end
+
+local function moveCursorToLineStart(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorToLineStart(element)
+  end
+end
+
+local function moveCursorToLineEnd(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorToLineEnd(element)
+  end
+end
+
+local function moveCursorToPreviousWord(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorToPreviousWord(element)
+  end
+end
+
+local function moveCursorToNextWord(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:moveCursorToNextWord(element)
+  end
+end
+
+-- --- Selection management ------------------------------------------------
+
+local function setSelection(element, startPos, endPos)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:setSelection(element, startPos, endPos)
+  end
+end
+
+local function getSelection(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    return textEditor:getSelection()
+  end
+  return nil
+end
+
+local function hasSelection(element)
+  local textEditor = element._textEditor
+  if textEditor ~= nil then
+    return textEditor:hasSelection()
+  end
+  return false
+end
+
+local function clearSelection(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:clearSelection(element)
+  end
+end
+
+local function selectAll(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:selectAll(element)
+  end
+end
+
+local function getSelectedText(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    return textEditor:getSelectedText()
+  end
+  return nil
+end
+
+local function deleteSelection(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    return textEditor:deleteSelection(element)
+  end
+  return false
+end
+
+-- --- Focus management ----------------------------------------------------
+
+local function focus(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:focus(element)
+  end
+end
+
+local function blur(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:blur(element)
+  end
+end
+
+local function isFocused(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    return textEditor:isFocused()
+  end
+  return false
+end
+
+-- --- Text buffer management (with post-delegation sync) ------------------
+-- These methods sync `element.text` from the TextEditor result + drive
+-- auto-grow, exactly as the legacy Element methods did.
+
+local function getText(element)
+  local textEditor = element._textEditor
+  if textEditor then
+    return textEditor:getText()
+  end
+  return element.text or ""
+end
+
+local function setText(element, text)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:setText(element, text)
+    element.text = textEditor:getText() -- Sync display text
+    textEditor:updateAutoGrowHeight(element)
+    return
+  end
+  element.text = text
+end
+
+local function insertText(element, text, position)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:insertText(element, text, position)
+    element.text = textEditor:getText() -- Sync display text
+    textEditor:updateAutoGrowHeight(element)
+  end
+end
+
+local function deleteText(element, startPos, endPos)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:deleteText(element, startPos, endPos)
+    element.text = textEditor:getText() -- Sync display text
+    textEditor:updateAutoGrowHeight(element)
+  end
+end
+
+local function replaceText(element, startPos, endPos, newText)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:replaceText(element, startPos, endPos, newText)
+    element.text = textEditor:getText() -- Sync display text
+    textEditor:updateAutoGrowHeight(element)
+  end
+end
+
+-- --- Mouse text selection ------------------------------------------------
+
+local function handleTextClick(element, mouseX, mouseY, clickCount)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:handleTextClick(element, mouseX, mouseY, clickCount)
+    -- Store mouse down position on element for drag tracking
+    if clickCount == 1 then
+      element._mouseDownPosition = textEditor:mouseToTextPosition(element, mouseX, mouseY)
+    end
+  end
+end
+
+local function handleTextDrag(element, mouseX, mouseY)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:handleTextDrag(element, mouseX, mouseY)
+    element._textDragOccurred = textEditor._textDragOccurred
+  end
+end
+
+-- --- Keyboard input ------------------------------------------------------
+
+local function textinput(element, text)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:handleTextInput(element, text)
+    element.text = textEditor:getText() -- Sync display text
+    textEditor:updateAutoGrowHeight(element)
+  end
+end
+
+local function keypressed(element, key, scancode, isrepeat)
+  local textEditor = element._textEditor
+  if textEditor then
+    textEditor:handleKeyPress(element, key, scancode, isrepeat)
+    element.text = textEditor:getText() -- Sync display text
+    textEditor:updateAutoGrowHeight(element)
+  end
+end
+
+-- ============================================================================
+-- Build the (stateless, shared, immutable) behavior instance + thin module
+-- table exposing the delegate functions (mirrors the Animated pattern).
+-- ============================================================================
+
+local behavior = Behavior.new({
+  onAttach = onAttach,
+  onDetach = onDetach,
+  onUpdate = onUpdate,
+  onDraw = onDraw,
+  saveState = saveState,
+  restoreState = restoreState,
+  shouldAttach = shouldAttach,
+})
+
+-- Thin module table: exposes the frozen behavior instance (for the registry)
+-- plus the text-editor delegate functions (for Element's 1-line forwarders).
+-- All hooks delegate to the frozen behavior instance so dispatch sites get
+-- the validated, frozen implementation. shouldAttach is also exposed at module
+-- level (mirrors Clickable.shouldAttach) for tests/callers without an element.
+local TextEditable = {
+  behavior = behavior,
+  shouldAttach = shouldAttach,
+  onAttach = onAttach,
+  onUpdate = onUpdate,
+  onDraw = onDraw,
+  saveState = saveState,
+  restoreState = restoreState,
+  -- Text-editor delegate functions (Element forwarders route through these):
+  setCursorPosition = setCursorPosition,
+  getCursorPosition = getCursorPosition,
+  moveCursorBy = moveCursorBy,
+  moveCursorToStart = moveCursorToStart,
+  moveCursorToEnd = moveCursorToEnd,
+  moveCursorToLineStart = moveCursorToLineStart,
+  moveCursorToLineEnd = moveCursorToLineEnd,
+  moveCursorToPreviousWord = moveCursorToPreviousWord,
+  moveCursorToNextWord = moveCursorToNextWord,
+  setSelection = setSelection,
+  getSelection = getSelection,
+  hasSelection = hasSelection,
+  clearSelection = clearSelection,
+  selectAll = selectAll,
+  getSelectedText = getSelectedText,
+  deleteSelection = deleteSelection,
+  focus = focus,
+  blur = blur,
+  isFocused = isFocused,
+  getText = getText,
+  setText = setText,
+  insertText = insertText,
+  deleteText = deleteText,
+  replaceText = replaceText,
+  _handleTextClick = handleTextClick,
+  _handleTextDrag = handleTextDrag,
+  textinput = textinput,
+  keypressed = keypressed,
+}
+
+-- Metatable so the module table itself satisfies the duck-typed registry
+-- contract (iterating `Element._behaviorRegistry` calls `behavior.shouldAttach`
+-- and `behavior.onAttach` / `behavior.onUpdate` directly). Falls through to the
+-- frozen behavior instance for every hook / isBehavior parity.
+setmetatable(TextEditable, {
+  __index = behavior,
+  __tostring = function()
+    return "TextEditable"
+  end,
+})
+
+return TextEditable

libs/flexlove/modules/behaviors/Themed.lua

@@ -0,0 +1,178 @@
+-- modules/behaviors/Themed.lua
+--
+-- Concrete behavior: Renderer ownership + theme-state rendering.
+--
+-- Themed owns the per-element Renderer instance and the single
+-- `Renderer:draw` call that paints the core visual layers (background, image,
+-- theme 9-patch, borders, text, customDraw). It is the behavior-mode-unification
+-- replacement for the former `_initImageAndRenderer` Renderer creation block and
+-- the former first `self._renderer:draw(self, backdropCanvas)` call in
+-- Element:draw (behavior-mode-unification task 07).
+--
+-- Attachment rule (shouldAttach): every renderable Element. The pre-refactor
+-- code unconditionally created a Renderer for every Element and unconditionally
+-- called `Renderer:draw` in Element:draw; Themed mirrors that invariant so the
+-- Renderer is always available to subsystems that depend on it (TextEditor font
+-- / wrap delegation, ScrollManager scrollbar drawing) AND so visual rendering of
+-- background / border / theme / image layers is preserved for every element.
+-- Restricting attachment to `themeComponent`-only elements would break editable
+-- text fields and scrollable containers (which need a Renderer for subsystem
+-- delegation even when they have no theme component). The 9-patch theme-state
+-- rendering within `Renderer:draw` is a no-op for elements without a
+-- `themeComponent`, so always-attaching carries no rendering cost.
+--
+-- Themed and Imageable are paired (both configure the same `element._renderer`):
+-- Themed.onAttach creates the Renderer with the theme/blur config; Imageable
+-- (attached for imagePath/image elements) enriches the SAME renderer instance with
+-- image config + deferred image loading. They share `element._renderer`.
+--
+-- onUpdate is a no-op: theme-state transitions are DRIVEN by the Clickable
+-- behavior (whose onUpdate recomputes hover/press/focus and calls
+-- `renderer:setThemeState`). Themed only READS that state for rendering, so it has
+-- no per-frame update work.
+--
+-- saveState owns the blur-region snapshot (`state.blur`): the per-frame blur
+-- geometry + radius/quality used by the Blur cache for invalidation (formerly
+-- the inline `if self.backdropBlur or self.contentBlur` block of
+-- Element:saveState — behavior-mode-unification task 12). restoreState is a
+-- no-op: blur cache data is used for invalidation, not restoration (the Blur
+-- cache is keyed by element id and cleared via `Blur.clearElementCache` from
+-- FlexLove.endFrame, not replayed through restoreState).
+--
+-- State ownership (per the locked Behavior contract):
+--   * Per-element runtime state lives ON THE ELEMENT (`element._renderer`,
+--     `element._themeState`, `element.backdropBlur`, `element.contentBlur`).
+--     The behavior instance is stateless and shared.
+--   * `element._renderer` is recreated on attach; onDetach is a no-op — the
+--     reference is released when the element is GC'd (Element:_cleanup keeps
+--     element structure for inspection).
+
+local _pkg = (...):match("^(.-)behaviors%.") or "modules."
+local Behavior = require(_pkg .. "Behavior")
+
+-- Resolve the Element class from an element instance (mirrors Clickable).
+-- Element instances are created via `setmetatable({}, Element)`, so their
+-- metatable IS the Element class — giving access to Element._Renderer,
+-- Element._rendererDeps, etc. without threading deps through the hook signature.
+local function ElementClass(element)
+  return getmetatable(element)
+end
+
+-- ----------------------------------------------------------------------------
+-- shouldAttach (class-level predicate, no element required)
+-- ----------------------------------------------------------------------------
+
+-- Returns true for every renderable Element. See file header for the rationale:
+-- the pre-refactor invariant was "every Element has a Renderer; Element:draw
+-- always calls Renderer:draw", and Thamed is the behavior-system embodiment of
+-- that invariant. Returns true for `themeComponent`-bearing props (the spec's
+-- headline case) and for every other element so subsystems/rendering stay intact.
+local function shouldAttach(props)
+  return true
+end
+
+-- ----------------------------------------------------------------------------
+-- onAttach — create the Renderer with theme/blur config (formerly the
+-- Renderer.new block of Element:_initImageAndRenderer).
+-- ----------------------------------------------------------------------------
+
+local function onAttach(element)
+  local Element = ElementClass(element)
+
+  -- Create-or-reuse the Renderer. Thamed is the first render behavior in the
+  -- registry, so it normally creates the instance; Imageable (if attached) will
+  -- reuse this same instance for image config. Guarded so Imageable-onAttach-
+  -- first (defensive) does not clobber an existing renderer.
+  if element._renderer then
+    return
+  end
+
+  -- NOTE: backgroundColor/borderColor/opacity/cornerRadius/themeComponent are
+  -- intentionally NOT passed here. Renderer:draw() reads them from the element
+  -- as the single source of truth (see Renderer.lua draw()). Only renderer-owned
+  -- state (theme, blur) is cached on the renderer; image config is added by the
+  -- Imageable behavior. border is element-sourced too.
+  element._renderer = Element._Renderer.new({
+    theme = element.theme,
+    scaleCorners = element.scaleCorners,
+    scalingAlgorithm = element.scalingAlgorithm,
+    contentBlur = element.contentBlur,
+    backdropBlur = element.backdropBlur,
+  }, Element._rendererDeps)
+end
+
+-- ----------------------------------------------------------------------------
+-- onDraw — the single Renderer:draw call (formerly the first call in
+-- Element:draw). Paints all core visual layers for this element.
+-- ----------------------------------------------------------------------------
+
+local function onDraw(element, ctx)
+  local renderer = element._renderer
+  if not renderer then
+    return
+  end
+  renderer:draw(element, ctx and ctx.backdropCanvas)
+end
+
+-- ----------------------------------------------------------------------------
+-- onDetach — no-op. Element:_cleanup preserves element structure for
+-- inspection (the original invariant), so the Renderer reference is released
+-- when the element is GC'd rather than torn down here. Present as an explicit
+-- hook so the behavior conforms to the full lifecycle contract.
+-- ----------------------------------------------------------------------------
+
+local function onDetach() end
+
+-- ----------------------------------------------------------------------------
+-- saveState — blur-region snapshot (formerly the `blur` branch of
+-- Element:saveState). Returns `{ blur = {...} }` when the element configures a
+-- backdrop or content blur, so the Blur cache can invalidate by element id;
+-- nil otherwise. Mode-agnostic to match the legacy contract (the snapshot is
+-- only read back by the cache-invalidation path, which itself is
+-- immediate-mode-only via FlexLove.endFrame).
+-- ----------------------------------------------------------------------------
+
+local function saveState(element)
+  if not (element.backdropBlur or element.contentBlur) then
+    return nil
+  end
+  local blur = {
+    _blurX = element.x,
+    _blurY = element.y,
+    _blurWidth = element._borderBoxWidth or (element.width + element.padding.left + element.padding.right),
+    _blurHeight = element._borderBoxHeight or (element.height + element.padding.top + element.padding.bottom),
+  }
+  if element.backdropBlur then
+    blur._backdropBlurRadius = element.backdropBlur.radius
+    blur._backdropBlurQuality = element.backdropBlur.quality or 5
+  end
+  if element.contentBlur then
+    blur._contentBlurRadius = element.contentBlur.radius
+    blur._contentBlurQuality = element.contentBlur.quality or 5
+  end
+  return { blur = blur }
+end
+
+-- restoreState — no-op: blur cache data is used for invalidation, not
+-- restoration (see file header). Present so the behavior conforms to the
+-- lifecycle contract without replaying geometry that the cache recomputes.
+
+-- ----------------------------------------------------------------------------
+-- Build the (stateless, shared, immutable) behavior instance.
+-- ----------------------------------------------------------------------------
+
+local Themed = Behavior.new({
+  onAttach = onAttach,
+  onDetach = onDetach,
+  onUpdate = function() end,
+  onDraw = onDraw,
+  saveState = saveState,
+  restoreState = function() end,
+})
+
+-- Expose the predicate at module level so callers/tests can reference it
+-- directly without an element instance (mirrors Behavior.shouldAttach /
+-- Clickable.shouldAttach).
+Themed.shouldAttach = shouldAttach
+
+return Themed

libs/flexlove/modules/types.lua

@@ -0,0 +1,662 @@
+---@class SelectOptionProps
+---@field value any -- Stable option value owned by the parent select
+---@field label string? -- Optional label override, falls back to the element text
+---@field disabled boolean? -- Whether the option can be selected
+local SelectOptionProps = {}
+
+---@class SelectParentProps
+---@field value any -- Currently selected option value
+---@field open boolean? -- Initial open state for the select container
+---@field placeholder string? -- Fallback text when no option is selected
+---@field selectFrame Element? -- Optional pre-instantiated dropdown container; intended to be unattached before being adopted by the select
+---@field onChange fun(element:Element, value:any, option:SelectOptionProps)? -- Called when selection changes
+local SelectParentProps = {}
+
+---@class Animation
+local Animation = {}
+
+---@class Color
+local Color = {}
+
+---@class Theme
+local Theme = {}
+
+---@class ThemeManager
+local ThemeManager = {}
+
+--=====================================--
+-- For Animation.lua
+--=====================================--
+---@alias EasingFunction fun(t:number): number
+
+---@class AnimationProps
+---@field duration number -- Duration in seconds
+---@field start table -- Starting values (can contain: width, height, opacity, x, y, gap, imageOpacity, backgroundColor, borderColor, textColor, padding, margin, cornerRadius, transform, etc.)
+---@field final table -- Final values (same properties as start)
+---@field easing string? -- Easing function name: "linear", "easeInQuad", "easeOutQuad", "easeInOutQuad", "easeInCubic", "easeOutCubic", "easeInOutCubic", "easeInQuart", "easeOutQuart", "easeInExpo", "easeOutExpo" (default: "linear")
+---@field keyframes AnimationKeyframe[]? -- Array of keyframes for complex animations
+---@field onStart fun(animation:Animation, element:Element?)? -- Called when animation starts
+---@field onUpdate fun(animation:Animation, element:Element?, progress:number)? -- Called each frame with progress (0-1)
+---@field onComplete fun(animation:Animation, element:Element?)? -- Called when animation completes
+---@field onCancel fun(animation:Animation, element:Element?)? -- Called when animation is cancelled
+---@field transform TransformProps? -- Additional transform properties (legacy support)
+---@field transition table? -- Transition properties (legacy support)
+local AnimationProps = {}
+
+---@class Transform
+---@field rotate number? Rotation in radians (default: 0)
+---@field scaleX number? X-axis scale (default: 1)
+---@field scaleY number? Y-axis scale (default: 1)
+---@field translateX number? X translation in pixels (default: 0)
+---@field translateY number? Y translation in pixels (default: 0)
+---@field skewX number? X-axis skew in radians (default: 0)
+---@field skewY number? Y-axis skew in radians (default: 0)
+---@field originX number? Transform origin X (0-1, default: 0.5)
+---@field originY number? Transform origin Y (0-1, default: 0.5)
+local Transform = {}
+
+---@alias TransformProps Transform
+
+---@class TransitionProps
+---@field duration number?
+---@field easing string?
+---@field delay number?
+---@field onComplete fun(element:Element)?
+
+--=====================================--
+-- For Element.lua
+--=====================================--
+---@class ElementProps
+---@field id string? -- Unique identifier for the element (auto-generated in immediate mode if not provided)
+---@field mode "immediate"|"retained"|nil -- Lifecycle mode override: "immediate" (auto-managed state), "retained" (manual state), nil (use global mode from FlexLove.getMode(), default)
+---@field parent Element? -- Parent element for hierarchical structure
+---@field x number|string|CalcObject? -- X coordinate: number (px), string ("50%", "10vw"), or CalcObject from FlexLove.calc() (default: 0)
+---@field y number|string|CalcObject? -- Y coordinate: number (px), string ("50%", "10vh"), or CalcObject from FlexLove.calc() (default: 0)
+---@field z number? -- Z-index for layering (default: 0, clamped to -999..999)
+---@field tabIndex number? -- Tab navigation order: >0 (explicit order, visited first), 0 or nil (natural document order), -1 (excluded from keyboard navigation)
+---@field width number|string|CalcObject? -- Width of the element: number (px), string ("50%", "10vw"), or CalcObject from FlexLove.calc() (default: calculated automatically)
+---@field height number|string|CalcObject? -- Height of the element: number (px), string ("50%", "10vh"), or CalcObject from FlexLove.calc() (default: calculated automatically)
+---@field minWidth number|string|CalcObject? -- Minimum width constraint: number (px), string ("50%", "10vw"), or CalcObject. Clamps both fixed `width` and the flex-distributed main size when horizontal.
+---@field maxWidth number|string|CalcObject? -- Maximum width constraint: number (px), string ("50%", "10vw"), or CalcObject. Clamps both fixed `width` and the flex-distributed main size when horizontal.
+---@field minHeight number|string|CalcObject? -- Minimum height constraint: number (px), string ("50%", "10vh"), or CalcObject. Clamps both fixed `height` and the flex-distributed main size when vertical.
+---@field maxHeight number|string|CalcObject? -- Maximum height constraint: number (px), string ("50%", "10vh"), or CalcObject. Clamps both fixed `height` and the flex-distributed main size when vertical.
+---@field top number|string|CalcObject? -- Offset from top edge: number (px), string ("50%", "10vh"), or CalcObject (CSS-style positioning)
+---@field right number|string|CalcObject? -- Offset from right edge: number (px), string ("50%", "10vw"), or CalcObject (CSS-style positioning)
+---@field bottom number|string|CalcObject? -- Offset from bottom edge: number (px), string ("50%", "10vh"), or CalcObject (CSS-style positioning)
+---@field left number|string|CalcObject? -- Offset from left edge: number (px), string ("50%", "10vw"), or CalcObject (CSS-style positioning)
+---@field border Border? -- Border configuration for the element
+---@field borderColor Color? -- Color of the border (default: black)
+---@field opacity number? -- Element opacity 0-1 (default: 1)
+---@field visibility "visible"|"hidden"? -- Element visibility (default: "visible")
+---@field display boolean? -- Whether element participates in layout, rendering, and hit testing (default: true). Set false for CSS display:none behavior (zero layout space, no rendering, no hit testing). NOTE: In retained mode, toggling at runtime requires setting the parent's `_dirty = true` or calling `layoutChildren()` on the parent to trigger re-layout.
+---@field backgroundColor Color? -- Background color (default: transparent)
+---@field cornerRadius number|{topLeft:number?, topRight:number?, bottomLeft:number?, bottomRight:number?}? -- Corner radius: number (all corners) or table for individual corners (default: 0)
+---@field gap number|string|CalcObject? -- Space between children elements: number (px), string ("50%", "10vw"), or CalcObject from FlexLove.calc() (default: 0)
+---@field padding number|string|CalcObject|{top:number|string|CalcObject?, right:number|string|CalcObject?, bottom:number|string|CalcObject?, left:number|string|CalcObject?, horizontal:number|string|CalcObject?, vertical:number|string|CalcObject?}? -- Padding around children: single value, string, CalcObject for all sides, or table for individual sides (default: {top=0, right=0, bottom=0, left=0})
+---@field margin number|string|CalcObject|{top:number|string|CalcObject?, right:number|string|CalcObject?, bottom:number|string|CalcObject?, left:number|string|CalcObject?, horizontal:number|string|CalcObject?, vertical:number|string|CalcObject?}? -- Margin around element: single value, string, CalcObject for all sides, or table for individual sides (default: {top=0, right=0, bottom=0, left=0})
+---@field text string? -- Text content to display (default: nil)
+---@field textAlign TextAlignSpec? -- Alignment of the text content: simple string, compound string ("top-left"), or {horizontal, vertical} table (default: START)
+---@field textColor Color? -- Color of the text content (default: black or theme text color)
+---@field textSize number|string? -- Font size: number (px), string with units ("2vh", "10%"), or preset ("xxs"|"xs"|"sm"|"md"|"lg"|"xl"|"xxl"|"3xl"|"4xl") (default: "md" or 12px)
+---@field minTextSize number? -- Minimum text size in pixels for auto-scaling
+---@field maxTextSize number? -- Maximum text size in pixels for auto-scaling
+---@field fontFamily string? -- Font family name from theme or path to font file (default: theme default or system default, inherits from parent)
+---@field autoScaleText boolean? -- Whether text should auto-scale with window size (default: true)
+---@field positioning Positioning? -- Layout positioning mode: "absolute"|"relative"|"flex"|"grid" (default: RELATIVE)
+---@field flexDirection FlexDirection? -- Direction of flex layout: "horizontal"|"vertical"|"row"|"column"|"row-reverse"|"column-reverse"|"horizontal-reverse"|"vertical-reverse" (row→horizontal, column→vertical, row-reverse→horizontal-reverse, column-reverse→vertical-reverse, default: HORIZONTAL)
+---@field justifyContent JustifyContent? -- Alignment of items along main axis (default: FLEX_START)
+---@field alignItems AlignItems? -- Alignment of items along cross axis (default: STRETCH)
+---@field alignContent AlignContent? -- Alignment of lines in multi-line flex containers (default: STRETCH)
+---@field flexWrap FlexWrap? -- Whether children wrap to multiple lines: "nowrap"|"wrap"|"wrap-reverse" (default: NOWRAP)
+---@field flex number|string? -- Shorthand for flexGrow, flexShrink, flexBasis: number (flex-grow only), string ("1 0 auto"), or nil (default: nil)
+---@field flexGrow number? -- How much the element should grow relative to siblings (default: 0)
+---@field flexShrink number? -- How much the element should shrink relative to siblings (default: 1)
+---@field flexBasis number|string|CalcObject? -- Initial size before growing/shrinking: number (px), string ("50%", "10vw", "auto"), or CalcObject (default: "auto")
+---@field justifySelf JustifySelf? -- Alignment of the item itself along main axis (default: AUTO)
+---@field alignSelf AlignSelf? -- Alignment of the item itself along cross axis (default: AUTO)
+---@field onEvent fun(element:Element, event:InputEvent)? -- Callback function for interaction events
+---@field onEventDeferred boolean? -- Whether onEvent callback should be deferred until after canvases are released (default: false)
+---@field onFocus fun(element:Element)? -- Callback when element receives focus
+---@field onFocusDeferred boolean? -- Whether onFocus callback should be deferred (default: false)
+---@field dropFocusOnSelection boolean? -- Override keyboard-navigation focus drop after Enter/Space activation (default: nil, uses KeyboardNavigation.config.dropFocusOnSelection)
+---@field onBlur fun(element:Element)? -- Callback when element loses focus
+---@field onBlurDeferred boolean? -- Whether onBlur callback should be deferred (default: false)
+---@field onTextInput fun(element:Element, text:string)? -- Callback when text is input
+---@field onTextInputDeferred boolean? -- Whether onTextInput callback should be deferred (default: false)
+---@field onTextChange fun(element:Element, text:string)? -- Callback when text content changes
+---@field onTextChangeDeferred boolean? -- Whether onTextChange callback should be deferred (default: false)
+---@field onEnter fun(element:Element)? -- Callback when Enter key is pressed
+---@field onEnterDeferred boolean? -- Whether onEnter callback should be deferred (default: false)
+---@field onCreate fun(element:Element, props:table)? -- Callback when element is created, receives the element and original creation props
+---@field onCreateDeferred boolean? -- Whether onCreate callback should be deferred (default: false)
+---@field onTouchEvent fun(element:Element, touchEvent:InputEvent)? -- Callback for touch-specific events (touchpress, touchmove, touchrelease)
+---@field onTouchEventDeferred boolean? -- Whether onTouchEvent callback should be deferred (default: false)
+---@field onGesture fun(element:Element, gesture:table)? -- Callback for recognized gestures (tap, swipe, pinch, etc.)
+---@field onGestureDeferred boolean? -- Whether onGesture callback should be deferred (default: false)
+---@field touchEnabled boolean? -- Whether the element responds to touch events (default: true)
+---@field multiTouchEnabled boolean? -- Whether the element supports multiple simultaneous touches (default: false)
+---@field transform TransformProps? -- Transform properties for animations and styling
+---@field transition TransitionProps? -- Transition settings for animations
+---@field customDraw fun(element:Element)? -- Custom rendering callback called after standard rendering but before visual feedback (default: nil)
+---@field gridRows number|table? -- Number of equal 1fr rows, or array of track specs (e.g. {"1fr","100px","auto"})
+---@field gridColumns number|table? -- Number of equal 1fr columns, or array of track specs (e.g. {"1fr","100px","auto"})
+---@field columnGap number|string|CalcObject? -- Gap between grid columns: number (px), string ("50%", "10vw"), or CalcObject from FlexLove.calc() (default: 0)
+---@field rowGap number|string|CalcObject? -- Gap between grid rows: number (px), string ("50%", "10vh"), or CalcObject from FlexLove.calc() (default: 0)
+---@field theme string? -- Theme name to use (e.g., "space", "metal"). Defaults to theme from flexlove.init()
+---@field themeComponent string? -- Theme component to use (e.g., "panel", "button", "input"). If nil, no theme is applied
+---@field disabled boolean? -- Whether the element is disabled (default: false)
+---@field active boolean? -- Whether the element is active/focused (for inputs, default: false)
+---@field disableHighlight boolean? -- Whether to disable the pressed state highlight overlay (default: false, or true when using themeComponent)
+---@field themeStateLock boolean|string? -- Lock theme state: true/"default" = lock to base state, false = normal behavior, string = specific state ("hover", "pressed", "active", "disabled") (default: false)
+---@field themeComponentDisabledStates string[]? -- List of theme states to suppress visually (e.g. {"hover", "pressed"}). Interaction logic still fires.
+---@field contentAutoSizingMultiplier {width:number?, height:number?}? -- Multiplier for auto-sized content dimensions (default: sourced from theme or {1, 1})
+---@field scaleCorners number? -- Scale multiplier for 9-patch corners/edges. E.g., 2 = 2x size (overrides theme setting)
+---@field scalingAlgorithm "nearest"|"bilinear"? -- Scaling algorithm for 9-patch corners: "nearest" (sharp/pixelated) or "bilinear" (smooth) (overrides theme setting)
+---@field contentBlur {radius:number, quality:number?}? -- Blur the element's content including children (radius: pixels, quality: 1-10, default(quality): 5)
+---@field backdropBlur {radius:number, quality:number?}? -- Blur content behind the element (radius: pixels, quality: 1-10, default(quality): 5)
+---@field editable boolean? -- Whether the element is editable (default: false)
+---@field multiline boolean? -- Whether the element supports multiple lines (default: false)
+---@field textWrap boolean|"word"|"char"? -- Text wrapping mode (default: false for single-line, "word" for multi-line)
+---@field maxLines number? -- Maximum number of lines (default: nil)
+---@field maxLength number? -- Maximum text length in characters (default: nil)
+---@field placeholder string? -- Placeholder text when empty (default: nil)
+---@field passwordMode boolean? -- Whether to display text as password (default: false, disables multiline)
+---@field inputType "text"|"number"|"email"|"url"? -- Input type for validation (default: "text")
+---@field textOverflow "clip"|"ellipsis"|"scroll"? -- Text overflow behavior (default: "clip")
+---@field scrollable boolean? -- Whether text is scrollable (default: false for single-line, true for multi-line)
+---@field autoGrow boolean? -- Whether element auto-grows with text (default: false for single-line, true for multi-line)
+---@field selectOnFocus boolean? -- Whether to select all text on focus (default: false)
+---@field cursorColor Color? -- Cursor color (default: nil, uses textColor)
+---@field selectionColor Color? -- Selection background color (default: nil, uses theme or default)
+---@field cursorBlinkRate number? -- Cursor blink rate in seconds (default: 0.5)
+---@field selectParent SelectParentProps? -- Parent-owned select/dropdown state and callbacks
+---@field selectOption SelectOptionProps? -- Option metadata attached to a child of a select parent
+---@field overflow "visible"|"hidden"|"scroll"|"auto"? -- Overflow behavior (default: "hidden")
+---@field overflowX "visible"|"hidden"|"scroll"|"auto"? -- X-axis overflow (overrides overflow)
+---@field overflowY "visible"|"hidden"|"scroll"|"auto"? -- Y-axis overflow (overrides overflow)
+---@field scrollbarWidth number? -- Width of scrollbar track in pixels (default: 12)
+---@field scrollbarColor Color? -- Scrollbar thumb color (default: Color.new(0.5, 0.5, 0.5, 0.8))
+---@field scrollbarTrackColor Color? -- Scrollbar track color (default: Color.new(0.2, 0.2, 0.2, 0.5))
+---@field scrollbarRadius number? -- Corner radius for scrollbar (default: 6)
+---@field scrollbarPadding number? -- Padding between scrollbar and edge (default: 2)
+---@field scrollSpeed number? -- Pixels per wheel notch (default: 20)
+---@field invertScroll boolean? -- Invert mouse wheel scroll direction (default: false)
+---@field smoothScrollEnabled boolean? -- Enable smooth scrolling animation for wheel events (default: false)
+---@field scrollBarStyle string? -- Scrollbar style name from theme (selects from theme.scrollbars, default: uses first scrollbar or fallback rendering)
+---@field scrollbarKnobOffset number|{x:number, y:number}|{horizontal:number, vertical:number}? -- Offset for scrollbar knob/handle position in pixels (number for both axes, or table for per-axis control, default: 0, adds to theme offset)
+---@field scrollbarPlacement "reserve-space"|"overlay"? -- Scrollbar rendering mode: "reserve-space" (reduces content area, default) or "overlay" (renders over content)
+---@field scrollbarBalance boolean? -- When true, reserve scrollbar space on both sides of content for visual balance (default: false)
+---@field hideScrollbars boolean|{vertical:boolean, horizontal:boolean}? -- Hide scrollbars (boolean for both, or table for individual control, default: false)
+---@field imagePath string? -- Path to image file (auto-loads via ImageCache)
+---@field image love.Image? -- Image object to display
+---@field objectFit "fill"|"contain"|"cover"|"scale-down"|"none"? -- Image fit mode (default: "fill")
+---@field objectPosition string? -- Image position like "center center", "top left", "50% 50%" (default: "center center")
+---@field imageOpacity number? -- Image opacity 0-1 (default: 1, combines with element opacity)
+---@field imageRepeat "no-repeat"|"repeat"|"repeat-x"|"repeat-y"|"space"|"round"? -- Image repeat/tiling mode (default: "no-repeat")
+---@field imageTint Color? -- Color to tint the image (default: nil/white, no tint)
+---@field onImageLoad fun(element:Element, image:love.Image)? -- Callback when image loads successfully
+---@field onImageLoadDeferred boolean? -- Whether onImageLoad callback should be deferred (default: false)
+---@field onImageError fun(element:Element, error:string)? -- Callback when image fails to load
+---@field onImageErrorDeferred boolean? -- Whether onImageError callback should be deferred (default: false)
+---@field _scrollX number? -- Internal: scroll X position (restored in immediate mode)
+---@field _scrollY number? -- Internal: scroll Y position (restored in immediate mode)
+---@field children? ElementProps[]
+---@field userdata table? -- User-defined data storage for custom properties
+---@field ariaRole ARIA? -- ARIA role for screen readers (e.g., "button", "link", "dialog")
+---@field ariaLabel string? -- Accessible name for screen readers (overrides text content)
+---@field ariaDescribedBy string? -- ID of element that describes this element
+---@field ariaExpanded boolean? -- Whether element is expanded/collapsed (for containers)
+---@field ariaPressed boolean? -- Whether element is pressed (for toggle buttons)
+---@field ariaChecked boolean? -- Whether element is checked (for checkboxes/radios)
+---@field ariaDisabled boolean? -- Whether element is disabled (overrides disabled property)
+---@field ariaBusy boolean? -- Whether element is processing (for live regions)
+---@field ariaLive "off"|"polite"|"assertive"? -- Live region priority for announcements
+local ElementProps = {}
+
+---@class Border
+---@field top boolean|number -- true sets width to 1px, number sets width to specified pixels (default: 0)
+---@field right boolean|number -- true sets width to 1px, number sets width to specified pixels (default: 0)
+---@field bottom boolean|number -- true sets width to 1px, number sets width to specified pixels (default: 0)
+---@field left boolean|number -- true sets width to 1px, number sets width to specified pixels (default: 0)
+local Border = {}
+
+--=====================================--
+-- For KeyboardNavigation.lua
+--=====================================--
+---@class KeyboardNavigationKeyConfig
+---@field next string -- Key used to move to the next focusable element
+---@field previous string -- Key used to move to the previous focusable element
+---@field up string -- Key used for directional navigation upward
+---@field down string -- Key used for directional navigation downward
+---@field left string -- Key used for directional navigation leftward
+---@field right string -- Key used for directional navigation rightward
+---@field activate string[] -- Keys that activate the currently focused element
+---@field dismiss string -- Key used to dismiss or clear the currently focused element
+---@field toggleDebug string -- Key used to toggle keyboard-navigation debug tooling
+---@field inspect string -- Key used to inspect the currently focused element in developer tools
+local KeyboardNavigationKeyConfig = {}
+
+---@class KeyboardNavigationDeveloperToolsConfig
+---@field enabled boolean? -- Enable keyboard-navigation developer tools (default: true)
+---@field showProperties boolean? -- Show focused element properties in developer tools (default: true)
+---@field highlightColor number[]? -- RGBA color used for keyboard-navigation debug highlighting (default: {1, 0.8, 0, 0.5})
+local KeyboardNavigationDeveloperToolsConfig = {}
+
+---@class KeyboardNavigationFocusIndicatorConfig
+---@field enabled boolean? -- Enable the keyboard focus indicator (default: true)
+---@field color number[]? -- RGBA color of the focus indicator (default: {0.2, 0.6, 1.0, 0.8})
+---@field lineWidth number? -- Focus indicator stroke width in pixels (default: 2)
+---@field inset number? -- Offset from the element bounds in pixels (default: -3)
+---@field borderRadius number? -- Focus indicator border radius in pixels (default: 4)
+---@field animationDuration number? -- Focus indicator entrance animation duration in seconds (default: 0.15)
+---@field pulseEnabled boolean? -- Enable pulse animation for the focus indicator when supported
+---@field pulseDuration number? -- Seconds per pulse cycle
+---@field pulseScaleMin number? -- Minimum scale during pulse animation
+---@field pulseScaleMax number? -- Maximum scale during pulse animation
+---@field draw fun(element:Element, bounds:table, style:KeyboardNavigationFocusIndicatorConfig)? -- Custom focus indicator renderer
+local KeyboardNavigationFocusIndicatorConfig = {}
+
+---@class KeyboardNavigationConfig
+---@field enabled boolean? -- Enable or disable keyboard navigation globally (default: true)
+---@field debugMode boolean? -- Enable keyboard-navigation debug logging (default: false)
+---@field keys KeyboardNavigationKeyConfig? -- Key bindings used by keyboard navigation
+---@field wrapAround boolean? -- Allow wrapping from last to first focusable element (default: true)
+---@field directionalNavigation boolean? -- Enable arrow-key directional navigation (default: true)
+---@field focusVisible boolean? -- Show the focus indicator for keyboard-driven focus (default: true)
+---@field autofocusOnCreate boolean? -- Auto-focus the first focusable element on creation (default: false)
+---@field dropFocusOnSelection boolean? -- Drop focus after Enter/Space activates an element (default: true)
+---@field developerTools KeyboardNavigationDeveloperToolsConfig? -- Developer tool settings for keyboard navigation
+---@field focusIndicator KeyboardNavigationFocusIndicatorConfig? -- Focus indicator style configuration
+local KeyboardNavigationConfig = {}
+
+--=====================================--
+-- For FlexLove.init()
+--=====================================--
+---@class FlexLoveConfig
+---@field baseScale {width:number?, height:number?}? -- Base resolution for responsive scaling (default: nil, no scaling)
+---@field theme string|ThemeDefinition? -- Theme name (string) or ThemeDefinition to use (default: nil, no theme)
+---@field immediateMode boolean? -- Enable immediate mode (React-like, recreates UI each frame) vs retained mode (default: false)
+---@field autoFrameManagement boolean? -- Automatically call beginFrame/endFrame (default: false)
+---@field stateRetentionFrames number? -- Number of frames to retain unused state in immediate mode (default: 60)
+---@field maxStateEntries number? -- Maximum number of state entries before forcing cleanup (default: 1000)
+---@field includeStackTrace boolean? -- Include stack traces in error messages (default: true)
+---@field reportingLogLevel LOG_LEVEL? -- Error log level: 1: critical, 2: error, 3: warn, 4: info, 5: debug/all (default: 3:warn)
+---@field errorLogTarget string? -- Error log target: "console", "file", "both" (default: "console")
+---@field errorLogFile string? -- Path to error log file (default: "flexlove_errors.log")
+---@field errorLogMaxSize number? -- Maximum error log file size in bytes (default: 1048576, 1MB)
+---@field maxErrorLogFiles number? -- Maximum number of rotated error log files (default: 5)
+---@field errorLogRotateEnabled boolean? -- Enable error log rotation (default: true)
+---@field performanceMonitoring boolean? -- Enable performance monitoring (default: true)
+---@field performanceHudKey string? -- Key to toggle performance HUD (default: "f3")
+---@field performanceHudPosition {x:number, y:number}? -- Position of performance HUD (default: {x=10, y=10})
+---@field performanceWarningThreshold number? -- Frame time warning threshold in ms (default: 13.0)
+---@field performanceCriticalThreshold number? -- Frame time critical threshold in ms (default: 16.67)
+---@field performanceLogToConsole boolean? -- Log performance metrics to console (default: false)
+---@field performanceWarnings boolean? -- Enable performance warnings (default: false)
+---@field memoryProfiling boolean? -- Enable memory profiling (default: false, auto-enabled in immediate mode)
+---@field gcStrategy string? -- Garbage collection strategy: "auto", "periodic", "manual", "disabled" (default: "auto")
+---@field gcMemoryThreshold number? -- Memory threshold in MB before forcing GC (default: 100)
+---@field gcInterval number? -- Frames between GC steps in periodic mode (default: 60)
+---@field gcStepSize number? -- Work units per GC step, higher = more aggressive (default: 200)
+---@field immediateModeBlurOptimizations boolean? -- Cache blur canvases in immediate mode to avoid re-rendering each frame (default: true)
+---@field keyboardNavigation boolean|KeyboardNavigationConfig? -- Enable keyboard navigation with defaults (`true`) or provide configuration overrides
+---@field debugDraw boolean? -- Enable debug draw overlay showing element boundaries with random colors (default: false)
+---@field debugDrawKey string? -- Key to toggle debug draw overlay at runtime (default: nil, no toggle key)
+local FlexLoveConfig = {}
+
+--=====================================--
+-- Public FlexLove API
+--=====================================--
+---@alias TextAlignCompound "top-left" | "top-center" | "top-right" | "center-left" | "center-center" | "center-right" | "bottom-left" | "bottom-center" | "bottom-right"
+---@alias TextAlignSpec TextAlign | TextAlignCompound | {horizontal: TextAlign, vertical: TextAlignVertical}
+
+---@class FlexLoveEnums
+---@field TextAlign TextAlign
+---@field TextAlignVertical TextAlignVertical
+---@field Positioning Positioning
+---@field FlexDirection FlexDirection
+---@field JustifyContent JustifyContent
+---@field JustifySelf JustifySelf
+---@field AlignItems AlignItems
+---@field AlignSelf AlignSelf
+---@field AlignContent AlignContent
+---@field FlexWrap FlexWrap
+---@field TextSize TextSize
+---@field ImageRepeat ImageRepeat
+---@field ARIA ARIA
+local FlexLoveEnums = {}
+
+---@class AnimationKeyframe
+---@field at number -- Normalized time position (0-1)
+---@field values table -- Property values at this keyframe
+---@field easing string|EasingFunction? -- Easing used between this and the next keyframe
+local AnimationKeyframe = {}
+
+---@class AnimationGroupProps
+---@field animations Animation[] -- Animations to coordinate
+---@field mode "parallel"|"sequence"|"stagger"? -- Group playback mode (default: "parallel")
+---@field stagger number? -- Delay between staggered animations in seconds (default: 0.1)
+---@field onComplete fun(group:AnimationGroup)? -- Called when all animations complete
+---@field onStart fun(group:AnimationGroup)? -- Called when the group starts
+local AnimationGroupProps = {}
+
+---@class AnimationGroup
+---@field animations Animation[]
+---@field mode "parallel"|"sequence"|"stagger"
+---@field stagger number
+---@field onComplete fun(group:AnimationGroup)?
+---@field onStart fun(group:AnimationGroup)?
+local AnimationGroup = {}
+
+---@class Animation
+---@field duration number
+---@field start table
+---@field final table
+---@field elapsed number
+---@field easing EasingFunction
+---@field keyframes AnimationKeyframe[]?
+---@field transform TransformProps?
+---@field transition TransitionProps?
+---@field onStart fun(animation:Animation, element:Element?)?
+---@field onUpdate fun(animation:Animation, element:Element?, progress:number)?
+---@field onComplete fun(animation:Animation, element:Element?)?
+---@field onCancel fun(animation:Animation, element:Element?)?
+---@field update fun(self:Animation, dt:number, element:table?): boolean
+---@field findKeyframes fun(self:Animation, progress:number): AnimationKeyframe?, AnimationKeyframe?
+---@field lerpKeyframes fun(self:Animation, prevFrame:AnimationKeyframe, nextFrame:AnimationKeyframe, easedT:number): table
+---@field interpolate fun(self:Animation): table
+---@field apply fun(self:Animation, element:table)
+---@field pause fun(self:Animation)
+---@field resume fun(self:Animation)
+---@field isPaused fun(self:Animation): boolean
+---@field reverse fun(self:Animation)
+---@field isReversed fun(self:Animation): boolean
+---@field setSpeed fun(self:Animation, speed:number)
+---@field getSpeed fun(self:Animation): number
+---@field seek fun(self:Animation, time:number)
+---@field getState fun(self:Animation): string
+---@field cancel fun(self:Animation, element:table?)
+---@field reset fun(self:Animation)
+---@field getProgress fun(self:Animation): number
+---@field chain fun(self:Animation, nextAnimation:Animation|function): Animation
+---@field delay fun(self:Animation, seconds:number): Animation
+---@field repeatCount fun(self:Animation, count:number): Animation
+---@field yoyo fun(self:Animation, enabled:boolean?): Animation
+---@class AnimationModule
+---@field Easing table<string, EasingFunction|fun(...):EasingFunction> -- Built-in easing functions and easing factories
+---@field Transform table? -- Animation transform helpers exposed by the animation module
+---@field Group AnimationGroup -- Animation group class table
+---@field new fun(props:AnimationProps): Animation
+---@field fade fun(duration:number, fromOpacity:number, toOpacity:number, easing:string?): Animation
+---@field scale fun(duration:number, fromScale:{width:number, height:number}, toScale:{width:number, height:number}, easing:string?): Animation
+---@field keyframes fun(props:{duration:number, keyframes:AnimationKeyframe[], onStart:function?, onUpdate:function?, onComplete:function?, onCancel:function?}): Animation
+---@field chainSequence fun(animations:Animation[]): Animation
+local AnimationModule = {}
+
+---@class ColorInputTable
+---@field [1] number?
+---@field [2] number?
+---@field [3] number?
+---@field [4] number?
+---@field r number?
+---@field g number?
+---@field b number?
+---@field a number?
+local ColorInputTable = {}
+
+---@alias ColorInput string|Color|ColorInputTable
+
+---@class ColorModule
+---@field new fun(r:number?, g:number?, b:number?, a:number?): Color
+---@field fromHex fun(hexWithTag:string): Color
+---@field validateColorChannel fun(value:any, max:number?): boolean, number?
+---@field validateHexColor fun(hex:string): boolean, string?
+---@field validateRGBColor fun(r:number, g:number, b:number, a:number?, max:number?): boolean, string?
+---@field isValidColorFormat fun(value:any): string?
+---@field sanitizeColor fun(value:any, default:Color?): Color
+---@field parse fun(value:any): Color
+---@field lerp fun(colorA:Color, colorB:Color, t:number): Color
+local ColorModule = {}
+
+---@class ThemeManagerConfig
+---@field theme string? -- Theme name override
+---@field themeComponent string? -- Component name to resolve from the theme
+---@field disabled boolean? -- Force disabled theme state
+---@field active boolean? -- Force active theme state
+---@field disableHighlight boolean? -- Disable pressed highlight overlay
+---@field themeStateLock boolean|string? -- Lock the theme state to base/default or a named state
+---@field themeComponentDisabledStates string[]? -- List of theme states to suppress visually
+---@field scaleCorners number? -- Scale multiplier for 9-patch corners and edges
+---@field scalingAlgorithm "nearest"|"bilinear"? -- Scaling algorithm for non-stretched theme regions
+local ThemeManagerConfig = {}
+
+---@class ThemeRegion
+---@field x number
+---@field y number
+---@field w number
+---@field h number
+local ThemeRegion = {}
+
+---@class ThemeComponent
+---@field atlas string|love.Image?
+---@field insets {left:number, top:number, right:number, bottom:number}?
+---@field regions {topLeft:ThemeRegion, topCenter:ThemeRegion, topRight:ThemeRegion, middleLeft:ThemeRegion, middleCenter:ThemeRegion, middleRight:ThemeRegion, bottomLeft:ThemeRegion, bottomCenter:ThemeRegion, bottomRight:ThemeRegion}?
+---@field stretch {horizontal:table<integer, string>, vertical:table<integer, string>}?
+---@field states table<string, ThemeComponent>?
+---@field contentAutoSizingMultiplier {width:number?, height:number?}?
+---@field scaleCorners number?
+---@field scalingAlgorithm "nearest"|"bilinear"?
+---@field knobOffset number|{x:number, y:number}|{horizontal:number, vertical:number}?
+local ThemeComponent = {}
+
+---@class ThemeDefinition
+---@field name string
+---@field atlas string|love.Image?
+---@field components table<string, ThemeComponent>
+---@field scrollbars table<string, ThemeComponent>?
+---@field colors table<string, Color>?
+---@field fonts table<string, string>?
+---@field contentAutoSizingMultiplier {width:number?, height:number?}?
+local ThemeDefinition = {}
+
+---@class Theme
+---@field name string
+---@field atlas love.Image?
+---@field atlasData love.ImageData?
+---@field components table<string, ThemeComponent>
+---@field scrollbars table<string, ThemeComponent>
+---@field colors table<string, Color>
+---@field fonts table<string, string>
+---@field contentAutoSizingMultiplier {width:number?, height:number?}?
+---@class ThemeManager
+---@field theme string?
+---@field themeComponent string?
+---@field disabled boolean
+---@field active boolean
+---@field disableHighlight boolean?
+---@field themeStateLock boolean|string?
+---@field themeComponentDisabledStates table<string, boolean>
+---@field scaleCorners number?
+---@field scalingAlgorithm "nearest"|"bilinear"?
+---@field updateState fun(self:ThemeManager, isHovered:boolean, isPressed:boolean, isFocused:boolean, isDisabled:boolean): string
+---@field getState fun(self:ThemeManager): string
+---@field setState fun(self:ThemeManager, state:string)
+---@field hasThemeComponent fun(self:ThemeManager): boolean
+---@field getTheme fun(self:ThemeManager): Theme?
+---@field getComponent fun(self:ThemeManager): ThemeComponent?
+---@field getStateComponent fun(self:ThemeManager): ThemeComponent?
+---@field getScrollbarComponent fun(self:ThemeManager, scrollbarName:string?): ThemeComponent?
+---@field getStyle fun(self:ThemeManager, property:string): any?
+---@field _getScaledContentPaddingForState fun(self:ThemeManager, state:string, borderBoxWidth:number, borderBoxHeight:number): table?
+---@field getScaledContentPaddingForState fun(self:ThemeManager, state:string, borderBoxWidth:number, borderBoxHeight:number): table? -- deprecated, use getScaledContentPadding
+---@field getScaledContentPadding fun(self:ThemeManager, borderBoxWidth:number, borderBoxHeight:number): table?
+---@field getContentAutoSizingMultiplier fun(self:ThemeManager): table?
+---@field getDefaultFontFamily fun(self:ThemeManager): string?
+---@field setTheme fun(self:ThemeManager, themeName:string?, componentName:string?)
+---@field validateThemeStateLock fun(self:ThemeManager): boolean
+---@class Color
+---@field r number
+---@field g number
+---@field b number
+---@field a number
+---@field toRGBA fun(self:Color): number, number, number, number
+---@class ThemeModule
+---@field Manager ThemeManager -- Theme manager class table
+---@field new fun(definition:ThemeDefinition): Theme
+---@field load fun(path:string): Theme?
+---@field setActive fun(themeOrName:string|Theme)
+---@field getActive fun(): Theme?
+---@field getComponent fun(componentName:string, state:string?): ThemeComponent?
+---@field getDefaultScrollbar fun(): ThemeComponent?
+---@field getScrollbar fun(scrollbarName:string, state:string?): ThemeComponent?
+---@field getFont fun(fontName:string): string?
+---@field getColor fun(colorName:string): Color?
+---@field hasActive fun(): boolean
+---@field getRegisteredThemes fun(): table<string, Theme>
+---@field getColorNames fun(): string[]
+---@field getAllColors fun(): table<string, Color>
+---@field getColorOrDefault fun(colorName:string, fallback:Color): Color
+---@field get fun(themeName:string): Theme?
+---@field validateTheme fun(theme:table?, options:table?): boolean, table
+---@field sanitizeTheme fun(theme:table?): table
+local ThemeModule = {}
+
+---@class FlexLove
+---@field _VERSION string
+---@field _DESCRIPTION string
+---@field _URL string
+---@field _LICENSE string
+---@field Animation AnimationModule?
+---@field Color ColorModule
+---@field Theme ThemeModule?
+---@field enums FlexLoveEnums
+---@field isReady fun(): boolean
+---@field init fun(config:FlexLoveConfig?)
+---@field setKeyboardNavigationDebug fun(enabled:boolean)
+---@field enableKeyboardNavigation fun(config:KeyboardNavigationConfig?)
+---@field deferCallback fun(callback:function)
+---@field executeDeferredCallbacks fun()
+---@field resize fun()
+---@field setMode fun(mode:"immediate"|"retained")
+---@field getMode fun(): "immediate"|"retained"
+---@field beginFrame fun()
+---@field endFrame fun()
+---@field draw fun(gameDrawFunc:function|nil, postDrawFunc:function|nil)
+---@field getElementAtPosition fun(x:number, y:number): Element?
+---@field update fun(dt:number)
+---@field collectGarbage fun(mode:string?, stepSize:number?): number?
+---@field setGCStrategy fun(strategy:"auto"|"periodic"|"manual"|"disabled")
+---@field getGCStats fun(): GCStats
+---@field textinput fun(text:string)
+---@field keypressed fun(key:string, scancode:string, isrepeat:boolean)
+---@field wheelmoved fun(dx:number, dy:number)
+---@field touchpressed fun(id:lightuserdata, x:number, y:number, dx:number, dy:number, pressure:number)
+---@field touchmoved fun(id:lightuserdata, x:number, y:number, dx:number, dy:number, pressure:number)
+---@field touchreleased fun(id:lightuserdata, x:number, y:number, dx:number, dy:number, pressure:number)
+---@field getActiveTouchCount fun(): number
+---@field getTouchOwner fun(touchId:string): Element?
+---@field getById fun(id:string): Element?
+---@field destroy fun()
+---@field new fun(props:ElementProps, callback:function?): Element?
+---@field getStateCount fun(): number
+---@field clearState fun(id:string)
+---@field clearAllStates fun()
+---@field getStateStats fun(): table
+---@field calc fun(expr:string): CalcObject
+---@field getFocusedElement fun(): Element?
+---@field setFocusedElement fun(element:Element?)
+---@field clearFocus fun()
+---@field setDebugDraw fun(enabled:boolean)
+---@field getDebugDraw fun(): boolean
+local FlexLove = {}
+
+--=====================================--
+-- For State Persistence
+--=====================================--
+---@class ElementStateData
+---@field _focused boolean?
+---@field eventHandler table? -- EventHandler state
+---@field textEditor table? -- TextEditor state
+---@field scrollManager table? -- ScrollManager state
+---@field blur BlurCacheData? -- Blur cache invalidation data
+
+---@class BlurCacheData
+---@field _blurX number
+---@field _blurY number
+---@field _blurWidth number
+---@field _blurHeight number
+---@field _backdropBlurRadius number?
+---@field _backdropBlurQuality number?
+---@field _contentBlurRadius number?
+---@field _contentBlurQuality number?
+
+--=====================================--
+-- For Calc.lua
+--=====================================--
+---@class CalcDependencies
+---@field ErrorHandler ErrorHandler? -- Error handler module
+
+---@class CalcToken
+---@field type string -- Token type: "NUMBER", "UNIT", "PLUS", "MINUS", "MULTIPLY", "DIVIDE", "LPAREN", "RPAREN", "EOF"
+---@field value number? -- Numeric value (for NUMBER tokens)
+---@field unit string? -- Unit type: "px", "%", "vw", "vh" (for NUMBER tokens)
+
+---@class CalcASTNode
+---@field type string -- Node type: "number", "add", "subtract", "multiply", "divide"
+---@field value number? -- Numeric value (for "number" nodes)
+---@field unit string? -- Unit type (for "number" nodes)
+---@field left CalcASTNode? -- Left operand (for operator nodes)
+---@field right CalcASTNode? -- Right operand (for operator nodes)
+
+---@class CalcObject
+---@field _isCalc boolean -- Marker to identify calc objects (always true)
+---@field _expr string -- Original expression string
+---@field _ast CalcASTNode? -- Parsed abstract syntax tree (nil if parsing failed)
+---@field _error string? -- Error message if parsing failed
+
+--=====================================--
+-- For FlexLove.lua Internals
+--=====================================--
+---@class GCConfig
+---@field strategy string -- "auto", "periodic", "manual", or "disabled"
+---@field memoryThreshold number -- MB before forcing GC
+---@field interval number -- Frames between GC steps (for periodic mode)
+---@field stepSize number -- Work units per GC step (higher = more aggressive)
+
+---@class GCState
+---@field framesSinceLastGC number -- Frames elapsed since last GC
+---@field lastMemory number -- Last recorded memory usage in MB
+---@field gcCount number -- Total number of GC operations performed
+
+---@class GCStats
+---@field gcCount number -- Total number of GC operations performed
+---@field framesSinceLastGC number -- Frames elapsed since last GC
+---@field currentMemoryMB number -- Current memory usage in MB
+---@field strategy string -- Current GC strategy
+---@field threshold number -- Memory threshold in MB
+
+---@class FlexLoveDependencies
+---@field Context table -- Context module
+---@field Theme Theme? -- Theme module
+---@field Color Color -- Color module
+---@field Calc Calc -- Calc module
+---@field Units table -- Units module
+---@field Blur table? -- Blur module
+---@field ImageRenderer table? -- ImageRenderer module
+---@field ImageScaler table? -- ImageScaler module
+---@field NinePatch table? -- NinePatch module
+---@field RoundedRect table -- RoundedRect module
+---@field ImageCache table? -- ImageCache module
+---@field utils table -- Utils module
+---@field Grid table -- Grid module
+---@field InputEvent table -- InputEvent module
+---@field GestureRecognizer table? -- GestureRecognizer module
+---@field StateManager StateManager -- StateManager module
+---@field TextEditor table -- TextEditor module
+---@field LayoutEngine LayoutEngine -- LayoutEngine module
+---@field Renderer table -- Renderer module
+---@field EventHandler EventHandler -- EventHandler module
+---@field ScrollManager table -- ScrollManager module
+---@field ErrorHandler ErrorHandler -- ErrorHandler module
+---@field Performance Performance? -- Performance module
+---@field Transform table? -- Transform module

libs/flexlove/modules/utils.lua

@@ -0,0 +1,319 @@
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+-- Focused sub-modules (utils now re-exports their surfaces as backward-compatible
+-- aliases so call sites needn't change). Loaded eagerly so the aliases resolve.
+local NumberValidation = req("NumberValidation")
+local TextSanitizer = req("TextSanitizer")
+local PathValidator = req("PathValidator")
+local FontCache = req("FontCache")
+local Enums = req("Enums")
+
+-- ErrorHandler is injected via init() (safeLoadImage closes over this upvalue).
+local ErrorHandler = nil
+
+local enums = Enums.enums
+
+-- Generic math, table, and path helpers (utils' own concern).
+-- All validation, font-cache, text-sanitization, and path-validation logic
+-- lives in the focused sub-modules above and is re-exported below.
+
+--- Get current keyboard modifiers state
+---@return {shift:boolean, ctrl:boolean, alt:boolean, super:boolean}
+local function getModifiers()
+  return {
+    shift = love.keyboard.isDown("lshift", "rshift"),
+    ctrl = love.keyboard.isDown("lctrl", "rctrl"),
+    alt = love.keyboard.isDown("lalt", "ralt"),
+    ---@diagnostic disable-next-line
+    super = love.keyboard.isDown("lgui", "rgui"), -- cmd/windows key
+  }
+end
+
+local TEXT_SIZE_PRESETS = {
+  ["2xs"] = 0.75,
+  xxs = 0.75,
+  xs = 1.25,
+  sm = 1.75,
+  md = 2.25,
+  lg = 2.75,
+  xl = 3.5,
+  xxl = 4.5,
+  ["2xl"] = 4.5,
+  ["3xl"] = 5.0,
+  ["4xl"] = 7.0,
+}
+
+--- Resolve text size preset to viewport units
+---@param sizeValue string|number
+---@return number?, string?
+local function resolveTextSizePreset(sizeValue)
+  if type(sizeValue) == "string" then
+    local preset = TEXT_SIZE_PRESETS[sizeValue]
+    if preset then
+      return preset, "vh"
+    end
+  end
+  return nil, nil
+end
+
+--- Auto-detect the base path where FlexLove is located
+---@return string filesystemPath
+local function getFlexLoveBasePath()
+  local info = debug.getinfo(1, "S")
+  if info and info.source then
+    local source = info.source
+    if source:sub(1, 1) == "@" then
+      source = source:sub(2)
+    end
+
+    local filesystemPath = source:match("(.*/)")
+    if filesystemPath then
+      local fsPath = filesystemPath
+      fsPath = fsPath:gsub("^%./", "")
+      fsPath = fsPath:gsub("/$", "")
+      fsPath = fsPath:gsub("/modules$", "")
+      return fsPath
+    end
+  end
+  return "libs"
+end
+
+local FLEXLOVE_FILESYSTEM_PATH = getFlexLoveBasePath()
+
+--- Helper function to resolve paths relative to FlexLove
+---@param path string
+---@return string
+local function resolveImagePath(path)
+  if path:match("^/") or path:match("^[A-Z]:") then
+    return path
+  end
+  return FLEXLOVE_FILESYSTEM_PATH .. "/" .. path
+end
+
+-- Math utilities
+
+--- Clamp a value between optional min/max bounds. Either bound may be nil.
+--- When both bounds are inverted (min > max), max wins (matches CSS behavior).
+---@param value number Value to clamp
+---@param min number|nil Minimum value (nil = no lower bound)
+---@param max number|nil Maximum value (nil = no upper bound)
+---@return number Clamped value
+local function clamp(value, min, max)
+  if min and value < min then
+    value = min
+  end
+  if max and value > max then
+    value = max
+  end
+  return value
+end
+
+--- Linear interpolation between two values
+---@param a number Start value
+---@param b number End value
+---@param t number Interpolation factor (0-1)
+---@return number Interpolated value
+local function lerp(a, b, t)
+  return a + (b - a) * t
+end
+
+--- Round a number to the nearest integer
+---@param value number Value to round
+---@return number Rounded value
+local function round(value)
+  return math.floor(value + 0.5)
+end
+
+-- Image utilities
+
+--- Safely load an image with error handling
+--- Returns both Image and ImageData to avoid deprecated getData() API
+---@param imagePath string Path to image file
+---@return love.Image?, love.ImageData?, string? Returns image, imageData, or nil with error message
+local function safeLoadImage(imagePath)
+  local success, imageData = pcall(function()
+    return love.image.newImageData(imagePath)
+  end)
+
+  if not success then
+    local errorMsg = string.format("Failed to load image data: %s - %s", imagePath, tostring(imageData))
+    if ErrorHandler then
+      ErrorHandler:warn("utils", "RES_004", {
+        resourceType = "image data",
+        path = imagePath,
+        error = tostring(imageData),
+      })
+    end
+    return nil, nil, errorMsg
+  end
+
+  local imageSuccess, image = pcall(function()
+    return love.graphics.newImage(imageData)
+  end)
+
+  if imageSuccess then
+    return image, imageData, nil
+  else
+    local errorMsg = string.format("Failed to create image: %s - %s", imagePath, tostring(image))
+    if ErrorHandler then
+      ErrorHandler:warn("utils", "RES_004", {
+        resourceType = "image",
+        path = imagePath,
+        error = tostring(image),
+      })
+    end
+    return nil, nil, errorMsg
+  end
+end
+
+-- Color manipulation utilities
+
+--- Brighten a color by a factor
+---@param r number Red component (0-1)
+---@param g number Green component (0-1)
+---@param b number Blue component (0-1)
+---@param a number Alpha component (0-1)
+---@param factor number Brightness factor (e.g., 1.2 for 20% brighter)
+---@return number, number, number, number Brightened color components
+local function brightenColor(r, g, b, a, factor)
+  return math.min(1, r * factor), math.min(1, g * factor), math.min(1, b * factor), a
+end
+
+-- Property normalization utilities
+
+--- Normalize a boolean or table property with vertical/horizontal fields
+---@param value boolean|table|nil Input value (boolean applies to both, table for individual control)
+---@param defaultValue boolean Default value if nil (default: false)
+---@return table Normalized table with vertical and horizontal fields
+local function normalizeBooleanTable(value, defaultValue)
+  defaultValue = defaultValue or false
+
+  if value == nil then
+    return { vertical = defaultValue, horizontal = defaultValue }
+  end
+
+  if type(value) == "boolean" then
+    return { vertical = value, horizontal = value }
+  end
+
+  if type(value) == "table" then
+    return {
+      vertical = value.vertical ~= nil and value.vertical or defaultValue,
+      horizontal = value.horizontal ~= nil and value.horizontal or defaultValue,
+    }
+  end
+
+  return { vertical = defaultValue, horizontal = defaultValue }
+end
+
+--- Normalize an offset value to {x, y} or {horizontal, vertical} format
+---@param value number|table|nil Input value (number applies to both, table for individual control)
+---@param defaultValue number Default value if nil (default: 0)
+---@return table Normalized table with x/y or horizontal/vertical fields
+local function normalizeOffsetTable(value, defaultValue)
+  defaultValue = defaultValue or 0
+
+  if value == nil then
+    return { x = defaultValue, y = defaultValue, horizontal = defaultValue, vertical = defaultValue }
+  end
+
+  if type(value) == "number" then
+    return { x = value, y = value, horizontal = value, vertical = value }
+  end
+
+  if type(value) == "table" then
+    -- Support both {x, y} and {horizontal, vertical} formats
+    local x = value.x or value.horizontal or defaultValue
+    local y = value.y or value.vertical or defaultValue
+    return {
+      x = x,
+      y = y,
+      horizontal = x,
+      vertical = y,
+    }
+  end
+
+  return { x = defaultValue, y = defaultValue, horizontal = defaultValue, vertical = defaultValue }
+end
+
+--- Apply content auto-sizing multiplier to a dimension
+---@param value number The dimension value
+---@param multiplier table? The contentAutoSizingMultiplier table {width:number?, height:number?}
+---@param axis "width"|"height" Which axis to apply
+---@return number The multiplied value
+local function applyContentMultiplier(value, multiplier, axis)
+  if multiplier and multiplier[axis] then
+    return value * multiplier[axis]
+  end
+  return value
+end
+
+--- Initialize dependencies
+---@param deps table Dependencies: { ErrorHandler = ErrorHandler }
+local function init(deps)
+  if type(deps) == "table" then
+    ErrorHandler = deps.ErrorHandler
+  end
+  -- Propagate shared ErrorHandler to focused sub-modules that need it.
+  NumberValidation.init({ ErrorHandler = ErrorHandler, clamp = clamp })
+  TextSanitizer.init({ ErrorHandler = ErrorHandler })
+  FontCache.init({ ErrorHandler = ErrorHandler, resolveImagePath = resolveImagePath })
+  -- PathValidator has no external dependencies.
+end
+
+return {
+  enums = enums,
+  FONT_CACHE = FontCache.FONT_CACHE,
+  resolveTextSizePreset = resolveTextSizePreset,
+  getModifiers = getModifiers,
+  TEXT_SIZE_PRESETS = TEXT_SIZE_PRESETS,
+  init = init,
+  clamp = clamp,
+  -- Alias for `clamp`; exposed under the size-clamping name so Element/LayoutEngine
+  -- and tests can reference min/max content-size clamping explicitly.
+  clampSize = clamp,
+  lerp = lerp,
+  round = round,
+  safeLoadImage = safeLoadImage,
+  brightenColor = brightenColor,
+  resolveImagePath = resolveImagePath,
+  normalizeBooleanTable = normalizeBooleanTable,
+  normalizeOffsetTable = normalizeOffsetTable,
+  applyContentMultiplier = applyContentMultiplier,
+  -- Backward-compatible aliases (delegated to focused sub-modules)
+  validateEnum = NumberValidation.validateEnum,
+  validateRange = NumberValidation.validateRange,
+  validateType = NumberValidation.validateType,
+  isNaN = NumberValidation.isNaN,
+  isInfinity = NumberValidation.isInfinity,
+  validateNumber = NumberValidation.validateNumber,
+  sanitizeNumber = NumberValidation.sanitizeNumber,
+  validateInteger = NumberValidation.validateInteger,
+  validatePercentage = NumberValidation.validatePercentage,
+  validateOpacity = NumberValidation.validateOpacity,
+  validateDegrees = NumberValidation.validateDegrees,
+  validateCoordinate = NumberValidation.validateCoordinate,
+  validateDimension = NumberValidation.validateDimension,
+  normalizePath = PathValidator.normalizePath,
+  sanitizePath = PathValidator.sanitizePath,
+  isPathSafe = PathValidator.isPathSafe,
+  validatePath = PathValidator.validatePath,
+  getFileExtension = PathValidator.getFileExtension,
+  hasAllowedExtension = PathValidator.hasAllowedExtension,
+  sanitizeText = TextSanitizer.sanitizeText,
+  validateTextInput = TextSanitizer.validateTextInput,
+  validateTextRange = TextSanitizer.validateTextRange,
+  escapeHtml = TextSanitizer.escapeHtml,
+  escapeLuaPattern = TextSanitizer.escapeLuaPattern,
+  stripNonPrintable = TextSanitizer.stripNonPrintable,
+  resolveFontPath = FontCache.resolveFontPath,
+  getFont = FontCache.getFont,
+  getFontCacheStats = FontCache.getFontCacheStats,
+  setFontCacheSize = FontCache.setFontCacheSize,
+  clearFontCache = FontCache.clearFontCache,
+  preloadFont = FontCache.preloadFont,
+  resetFontCacheStats = FontCache.resetFontCacheStats,
+}