Fix hidden battle UI overlay backgrounds

src/battle/BattleState.lua

@@ -27,6 +27,7 @@ local Timing = require("src.core.Timing")
 local TrainerAI = require("src.battle.TrainerAI")
 local TurnOrder = require("src.battle.TurnOrder")
 local TypeChart = require("src.battle.TypeChart")
+local UIVisibility = require("src.battle.UIVisibility")
 local RomText = require("src.core.RomText")
 local Strings = require("src.core.Strings")
 local WideBattle = require("src.battle.WideBattle")
@@ -134,9 +135,7 @@ function BattleState:sgbPalettes()
 end
 
 function BattleState:bottomUIVisible()
-  if not Runtime.wantsHook("battle.bottom_ui_visible") then return true end
-  return Runtime.call("battle.bottom_ui_visible", function() return true end,
-                      self) ~= false
+  return UIVisibility.bottomVisible(self, true)
 end
 
 function BattleState:statusHUDVisible()

src/battle/UIVisibility.lua

@@ -0,0 +1,39 @@
+-- Shared visibility rules for battle-owned UI states.  Text and choice
+-- overlays live above BattleState on the state stack, but they are still part
+-- of its bottom UI layer and must inherit that layer's visibility.
+
+local Runtime = require("src.mods.Runtime")
+
+local UIVisibility = {}
+
+local function enclosingBattle(state)
+  local stack = state and state.game and state.game.stack
+  local states = stack and stack.states
+  local found = false
+  for i = #(states or {}), 1, -1 do
+    local candidate = states[i]
+    if candidate == state then found = true end
+    if found and candidate and candidate.isBattle then return candidate end
+  end
+  return nil
+end
+
+-- queryState keeps the existing TextBox contract: a mod may still decide
+-- visibility for that individual box.  ChoiceBox only inherits the enclosing
+-- battle decision, so field YES/NO prompts never become battle-hook states.
+function UIVisibility.bottomVisible(state, queryState)
+  if not Runtime.wantsHook("battle.bottom_ui_visible") then return true end
+  local battle = enclosingBattle(state)
+  if battle and battle ~= state
+      and Runtime.call("battle.bottom_ui_visible",
+                       function() return true end, battle) == false then
+    return false
+  end
+  if queryState or battle == state then
+    return Runtime.call("battle.bottom_ui_visible",
+                        function() return true end, state) ~= false
+  end
+  return true
+end
+
+return UIVisibility

src/render/TextBox.lua

@@ -7,7 +7,7 @@
 -- the text is exhausted and A is pressed, then calls onDone.
 
 local Font = require("src.render.Font")
-local Runtime = require("src.mods.Runtime")
+local UIVisibility = require("src.battle.UIVisibility")
 local Theme = require("src.ui.Theme")
 local Timing = require("src.core.Timing")
 
@@ -346,11 +346,7 @@ function TextBox:update(dt)
 end
 
 function TextBox:draw()
-  if Runtime.wantsHook("battle.bottom_ui_visible")
-      and Runtime.call("battle.bottom_ui_visible", function() return true end,
-                       self) == false then
-    return
-  end
+  if not UIVisibility.bottomVisible(self, true) then return end
   -- The dialogue box belongs against the bottom of the screen, not floating
   -- in the middle of a zoomed-out letterbox.  Declared per frame; the
   -- renderer blits this region to the screen edge and the rest of the UI

src/ui/ChoiceBox.lua

@@ -1,6 +1,7 @@
 -- YES/NO choice box (InitYesNoTextBoxParameters: above the text box, right).
 
 local Font = require("src.render.Font")
+local UIVisibility = require("src.battle.UIVisibility")
 local Theme = require("src.ui.Theme")
 local Strings = require("src.core.Strings")
 local Timing = require("src.core.Timing")
@@ -67,6 +68,7 @@ function ChoiceBox:update(dt)
 end
 
 function ChoiceBox:draw()
+  if not UIVisibility.bottomVisible(self, false) then return end
   local tx, ty, tw, th = self.tx, self.ty, self.tw, self.th
   -- rides the same bottom anchor as the dialogue box it sits above, so the
   -- pair travels together (the anchor keeps each element's gap from the edge)