Route brush preset list planning

src/app_core/brush_ui.h

@@ -28,6 +28,14 @@ enum class BrushTextureListOperation {
     move_texture,
 };
 
+enum class BrushPresetListOperation {
+    add_current_brush,
+    remove_preset,
+    move_preset,
+    select_preset,
+    clear_presets,
+};
+
 enum class BrushStrokeControlOperation {
     set_float,
     set_bool,
@@ -139,6 +147,20 @@ struct BrushTextureListPlan {
     bool no_op = false;
 };
 
+struct BrushPresetListPlan {
+    BrushPresetListOperation operation = BrushPresetListOperation::select_preset;
+    int item_count = 0;
+    int current_index = -1;
+    int target_index = -1;
+    int move_offset = 0;
+    bool saves_list = false;
+    bool updates_empty_notification = false;
+    bool selects_target = false;
+    bool clears_selection = false;
+    bool notifies_brush_changed = false;
+    bool no_op = false;
+};
+
 struct BrushStrokeControlPlan {
     BrushStrokeControlOperation operation = BrushStrokeControlOperation::set_float;
     BrushStrokeFloatSetting float_setting = BrushStrokeFloatSetting::tip_size;
@@ -474,6 +496,122 @@ public:
     return pp::foundation::Result<BrushTextureListPlan>::success(plan);
 }
 
+[[nodiscard]] inline pp::foundation::Result<BrushPresetListPlan> plan_brush_preset_list_add(
+    int item_count,
+    bool has_current_brush)
+{
+    if (item_count < 0) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::out_of_range("brush preset item count must not be negative"));
+    }
+    if (!has_current_brush) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::invalid_argument("current brush must be available to add a preset"));
+    }
+
+    BrushPresetListPlan plan;
+    plan.operation = BrushPresetListOperation::add_current_brush;
+    plan.item_count = item_count;
+    plan.target_index = item_count;
+    plan.saves_list = true;
+    plan.updates_empty_notification = true;
+    return pp::foundation::Result<BrushPresetListPlan>::success(plan);
+}
+
+[[nodiscard]] inline pp::foundation::Result<BrushPresetListPlan> plan_brush_preset_list_remove(
+    int item_count,
+    int current_index)
+{
+    if (item_count <= 0) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::invalid_argument("brush preset list must contain an item to remove"));
+    }
+    if (current_index < 0 || current_index >= item_count) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::out_of_range("selected brush preset index is outside the list"));
+    }
+
+    BrushPresetListPlan plan;
+    plan.operation = BrushPresetListOperation::remove_preset;
+    plan.item_count = item_count;
+    plan.current_index = current_index;
+    plan.target_index = item_count > 1 ? std::min(current_index, item_count - 2) : -1;
+    plan.saves_list = true;
+    plan.updates_empty_notification = true;
+    plan.selects_target = plan.target_index >= 0;
+    plan.clears_selection = plan.target_index < 0;
+    return pp::foundation::Result<BrushPresetListPlan>::success(plan);
+}
+
+[[nodiscard]] inline pp::foundation::Result<BrushPresetListPlan> plan_brush_preset_list_move(
+    int item_count,
+    int current_index,
+    int offset)
+{
+    if (item_count <= 0) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::invalid_argument("brush preset list must contain an item to move"));
+    }
+    if (current_index < 0 || current_index >= item_count) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::out_of_range("selected brush preset index is outside the list"));
+    }
+    if (offset == 0) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::invalid_argument("brush preset move offset must not be zero"));
+    }
+
+    BrushPresetListPlan plan;
+    plan.operation = BrushPresetListOperation::move_preset;
+    plan.item_count = item_count;
+    plan.current_index = current_index;
+    plan.target_index = std::clamp(current_index + offset, 0, item_count - 1);
+    plan.move_offset = offset;
+    plan.saves_list = true;
+    plan.no_op = plan.target_index == current_index;
+    return pp::foundation::Result<BrushPresetListPlan>::success(plan);
+}
+
+[[nodiscard]] inline pp::foundation::Result<BrushPresetListPlan> plan_brush_preset_list_select(
+    int item_count,
+    int index)
+{
+    if (item_count <= 0) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::invalid_argument("brush preset list must contain an item to select"));
+    }
+    if (index < 0 || index >= item_count) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::out_of_range("selected brush preset index is outside the list"));
+    }
+
+    BrushPresetListPlan plan;
+    plan.operation = BrushPresetListOperation::select_preset;
+    plan.item_count = item_count;
+    plan.current_index = index;
+    plan.target_index = index;
+    plan.selects_target = true;
+    plan.notifies_brush_changed = true;
+    return pp::foundation::Result<BrushPresetListPlan>::success(plan);
+}
+
+[[nodiscard]] inline pp::foundation::Result<BrushPresetListPlan> plan_brush_preset_list_clear(int item_count)
+{
+    if (item_count < 0) {
+        return pp::foundation::Result<BrushPresetListPlan>::failure(
+            pp::foundation::Status::out_of_range("brush preset item count must not be negative"));
+    }
+
+    BrushPresetListPlan plan;
+    plan.operation = BrushPresetListOperation::clear_presets;
+    plan.item_count = item_count;
+    plan.saves_list = true;
+    plan.updates_empty_notification = true;
+    plan.clears_selection = true;
+    plan.no_op = item_count == 0;
+    return pp::foundation::Result<BrushPresetListPlan>::success(plan);
+}
+
 [[nodiscard]] inline pp::foundation::Status execute_brush_ui_plan(
     const BrushUiPlan& plan,
     BrushUiServices& services)