Extract canvas tool UI planning

src/app_core/canvas_tool_ui.h

@@ -0,0 +1,86 @@
+#pragma once
+
+#include "foundation/result.h"
+
+namespace pp::app {
+
+enum class CanvasToolOperation {
+    select_mode,
+    toggle_picking,
+    toggle_touch_lock,
+};
+
+enum class CanvasToolMode {
+    draw,
+    erase,
+    line,
+    camera,
+    grid,
+    copy,
+    cut,
+    fill,
+    mask_free,
+    mask_line,
+    flood_fill,
+};
+
+enum class CanvasToolTransformAction {
+    none,
+    copy,
+    cut,
+};
+
+struct CanvasToolPlan {
+    CanvasToolOperation operation = CanvasToolOperation::select_mode;
+    CanvasToolMode mode = CanvasToolMode::draw;
+    CanvasToolTransformAction transform_action = CanvasToolTransformAction::none;
+    bool selects_toolbar_button = false;
+    bool updates_canvas_mode = false;
+    bool toggles_picking = false;
+    bool toggles_touch_lock = false;
+    bool requires_draw_mode = false;
+    bool no_op = false;
+};
+
+[[nodiscard]] inline constexpr CanvasToolTransformAction transform_action_for_mode(CanvasToolMode mode) noexcept
+{
+    if (mode == CanvasToolMode::copy) {
+        return CanvasToolTransformAction::copy;
+    }
+    if (mode == CanvasToolMode::cut) {
+        return CanvasToolTransformAction::cut;
+    }
+    return CanvasToolTransformAction::none;
+}
+
+[[nodiscard]] inline constexpr CanvasToolPlan plan_canvas_tool_select(CanvasToolMode mode) noexcept
+{
+    CanvasToolPlan plan;
+    plan.operation = CanvasToolOperation::select_mode;
+    plan.mode = mode;
+    plan.transform_action = transform_action_for_mode(mode);
+    plan.selects_toolbar_button = true;
+    plan.updates_canvas_mode = true;
+    return plan;
+}
+
+[[nodiscard]] inline constexpr CanvasToolPlan plan_canvas_tool_pick_toggle(bool current_mode_is_draw) noexcept
+{
+    CanvasToolPlan plan;
+    plan.operation = CanvasToolOperation::toggle_picking;
+    plan.mode = CanvasToolMode::draw;
+    plan.requires_draw_mode = true;
+    plan.toggles_picking = current_mode_is_draw;
+    plan.no_op = !current_mode_is_draw;
+    return plan;
+}
+
+[[nodiscard]] inline constexpr CanvasToolPlan plan_canvas_tool_touch_lock_toggle() noexcept
+{
+    CanvasToolPlan plan;
+    plan.operation = CanvasToolOperation::toggle_touch_lock;
+    plan.toggles_touch_lock = true;
+    return plan;
+}
+
+} // namespace pp::app