Convert visual layers to scene nodes.

src/ui_elements/widgets/Widget.h

@@ -10,7 +10,9 @@ class MouseEvent;
 class KeyboardEvent;
 class PaintEvent;
 
-class VisualLayer;
+class AbstractVisualNode;
+class TransformNode;
+class RectangleNode;
 
 class Widget
 {
@@ -71,7 +73,7 @@ public:
 
     BoundedSize getSize() const;
 
-    std::vector<VisualLayer*> getLayers() const;
+    TransformNode* getRootNode() const;
 
     const DiscretePoint& getLocation() const;
 
@@ -106,27 +108,38 @@ protected:
 
     virtual void onMyMouseEvent(const MouseEvent* event);
 
-    virtual void addChildLayers(const PaintEvent* event);
+    virtual void updateBackground(const PaintEvent* event);
 
-    virtual void addBackground(const PaintEvent* event);
+    virtual void doPaint(const PaintEvent* event);
+
+    virtual void updateChildLocations();
 
     void addMyLayers();
 
     bool needsUpdate() const;
 
 protected:
+    virtual bool isDirty() const;
+
     DiscretePoint mLocation;
     BoundedSize mSize;
     BoundaryOffset mPadding;
     BoundaryOffset mMargin;
-    std::vector<std::unique_ptr<VisualLayer> > mMyLayers;
-    std::vector<VisualLayer*> mLayers;
+
+    std::unique_ptr<TransformNode> mRootNode;
     std::vector<std::unique_ptr<Widget> > mChildren;
     unsigned mBorderThickness{0};
     Color mBackgroundColor;
     Color mBorderColor;
     bool mVisible{false};
-    bool mDirty{true};
+
+    std::unique_ptr<RectangleNode> mBackgroundNode;
+
+    bool mTransformDirty{true};
+    bool mMaterialDirty{true};
+    bool mVisibilityDirty{true};
+
+    std::vector<TransformNode*> mPendingChildNodes;
 };
 
 using WidgetUPtr = std::unique_ptr<Widget>;