early tui layout

tui/src/dashboard_layout.h

@@ -0,0 +1,66 @@
+#pragma once
+
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace Prism::Tui {
+
+enum class PanelId {
+    Spectrum,
+    Levels,
+};
+
+enum class SplitAxis {
+    Rows,
+    Columns,
+};
+
+enum class LayoutPreset {
+    Automatic,
+    Stacked,
+    Columns,
+};
+
+struct LayoutNode {
+    std::optional<PanelId> panel;
+    SplitAxis axis = SplitAxis::Rows;
+    int weight = 1;
+    std::vector<LayoutNode> children;
+
+    static LayoutNode leaf(PanelId panel, int weight = 1);
+    static LayoutNode split(SplitAxis axis,
+                            std::vector<LayoutNode> children,
+                            int weight = 1);
+    bool isLeaf() const { return panel.has_value(); }
+};
+
+struct PanelRect {
+    PanelId panel = PanelId::Spectrum;
+    int x = 0;
+    int y = 0;
+    int width = 0;
+    int height = 0;
+};
+
+struct DashboardLayout {
+    bool terminalTooSmall = true;
+    LayoutPreset requestedPreset = LayoutPreset::Automatic;
+    LayoutPreset resolvedPreset = LayoutPreset::Stacked;
+    LayoutNode root;
+    std::vector<PanelRect> panels;
+};
+
+constexpr int kMinimumTerminalWidth = 44;
+constexpr int kMinimumTerminalHeight = 12;
+
+DashboardLayout buildDashboardLayout(int width,
+                                     int height,
+                                     LayoutPreset requestedPreset,
+                                     std::optional<PanelId> expandedPanel = std::nullopt);
+LayoutPreset nextLayoutPreset(LayoutPreset preset);
+std::string layoutPresetName(LayoutPreset preset);
+std::vector<PanelId> panelOrder();
+PanelId nextPanel(PanelId panel, bool reverse = false);
+
+}  // namespace Prism::Tui