Animated Rotation

ui/gfx/compositor/layer.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_COMPOSITOR_LAYER_H_
 #define UI_GFX_COMPOSITOR_LAYER_H_
 #pragma once
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
+#include "base/observer_list.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/compositor/compositor.h"
 
 class SkCanvas;
 
 namespace ui {
 
 class Compositor;
+class LayerObserver;
 class Texture;
 
 // Layer manages a texture, transform and a set of child Layers. Any View that
 // has enabled layers ends up creating a Layer to manage the texture.
 //
 // NOTE: unlike Views, each Layer does *not* own its children views. If you
 // delete a Layer and it has children, the parent of each child layer is set to
 // NULL, but the children are not deleted.
 class COMPOSITOR_EXPORT Layer {
  public:
@@ skipping 41 matching lines @@
   const Compositor* compositor() const { return compositor_; }
   Compositor* compositor() { return compositor_; }
 
   // Passing NULL will cause the layer to get a texture from its compositor.
   void SetTexture(ui::Texture* texture);
   const ui::Texture* texture() const { return texture_.get(); }
 
   // Resets the canvas of the texture.
   void SetCanvas(const SkCanvas& canvas, const gfx::Point& origin);
 
+  // Layers do not own observers. It is the responsibility of the observer to
+  // remove itself when it is done observing.
+  void AddObserver(LayerObserver* observer);
+  void RemoveObserver(LayerObserver* observer);
+
 // Draws the layer with hole if hole is non empty.
 // hole looks like:
 //
 //  layer____________________________
 //  |xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
 //  |xxxxxxxxxxxxx top xxxxxxxxxxxxxx|
 //  |________________________________|
 //  |xxxxx|                    |xxxxx|
 //  |xxxxx|      Hole Rect     |xxxxx|
 //  |left | (not composited)   |right|
@@ skipping 35 matching lines @@
   std::vector<Layer*> children_;
 
   ui::Transform transform_;
 
   gfx::Rect bounds_;
 
   bool fills_bounds_opaquely_;
 
   gfx::Rect hole_rect_;
 
+  ObserverList<LayerObserver> observer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_GFX_COMPOSITOR_LAYER_H_