Route brush refresh view through app core

src/app_core/brush_ui.h

@@ -212,6 +212,37 @@ struct BrushStrokePanelView {
     bool updates_thumbnails = true;
 };
 
+struct BrushUiRefreshInput {
+    bool update_color = false;
+    bool update_brush = false;
+    bool has_current_brush = true;
+    bool has_floating_picker = false;
+    bool has_floating_color_panel = false;
+    float tip_flow = 0.0F;
+    float tip_size = 0.0F;
+    float r = 0.0F;
+    float g = 0.0F;
+    float b = 0.0F;
+    float a = 1.0F;
+};
+
+struct BrushUiRefreshView {
+    bool updates_stroke_controls = false;
+    bool updates_quick_flow = false;
+    bool updates_quick_size = false;
+    bool updates_quick_brush_preview = false;
+    bool updates_quick_color = false;
+    bool updates_floating_picker = false;
+    bool updates_floating_color_panel = false;
+    bool no_op = false;
+    float tip_flow = 0.0F;
+    float tip_size = 0.0F;
+    float r = 0.0F;
+    float g = 0.0F;
+    float b = 0.0F;
+    float a = 1.0F;
+};
+
 class BrushUiServices {
 public:
     virtual ~BrushUiServices() = default;
@@ -342,6 +373,57 @@ public:
     return pp::foundation::Result<BrushStrokePanelView>::success(std::move(view));
 }
 
+[[nodiscard]] inline pp::foundation::Result<BrushUiRefreshView> plan_brush_ui_refresh(
+    const BrushUiRefreshInput& input)
+{
+    if (!input.update_color && !input.update_brush) {
+        BrushUiRefreshView view;
+        view.no_op = true;
+        return pp::foundation::Result<BrushUiRefreshView>::success(view);
+    }
+
+    if (!input.has_current_brush) {
+        return pp::foundation::Result<BrushUiRefreshView>::failure(
+            pp::foundation::Status::invalid_argument("brush refresh requires a current brush"));
+    }
+
+    if (input.update_brush) {
+        const auto flow_status = validate_brush_stroke_float(input.tip_flow);
+        if (!flow_status.ok()) {
+            return pp::foundation::Result<BrushUiRefreshView>::failure(flow_status);
+        }
+        const auto size_status = validate_brush_stroke_float(input.tip_size);
+        if (!size_status.ok()) {
+            return pp::foundation::Result<BrushUiRefreshView>::failure(size_status);
+        }
+    }
+
+    if (input.update_color) {
+        for (const auto value : { input.r, input.g, input.b, input.a }) {
+            const auto channel_status = validate_brush_ui_color_channel(value);
+            if (!channel_status.ok()) {
+                return pp::foundation::Result<BrushUiRefreshView>::failure(channel_status);
+            }
+        }
+    }
+
+    BrushUiRefreshView view;
+    view.updates_stroke_controls = input.update_brush;
+    view.updates_quick_flow = input.update_brush;
+    view.updates_quick_size = input.update_brush;
+    view.updates_quick_brush_preview = input.update_brush;
+    view.updates_quick_color = input.update_color;
+    view.updates_floating_picker = input.update_color && input.has_floating_picker;
+    view.updates_floating_color_panel = input.update_color && input.has_floating_color_panel;
+    view.tip_flow = input.tip_flow;
+    view.tip_size = input.tip_size;
+    view.r = input.r;
+    view.g = input.g;
+    view.b = input.b;
+    view.a = input.a;
+    return pp::foundation::Result<BrushUiRefreshView>::success(view);
+}
+
 [[nodiscard]] inline pp::foundation::Result<BrushUiPlan> plan_brush_ui_color(
     float r,
     float g,