Allows observers to be notified when layer animations complete.

ui/gfx/compositor/layer_animation_sequence.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_ANIMATION_SEQUENCE_H_
 #define UI_GFX_COMPOSITOR_LAYER_ANIMATION_SEQUENCE_H_
 #pragma once
 
 #include <vector>
 
 #include "base/memory/linked_ptr.h"
+#include "base/observer_list.h"
 #include "base/time.h"
 #include "ui/gfx/compositor/compositor_export.h"
 #include "ui/gfx/compositor/layer_animation_element.h"
 
 namespace ui {
 
 class LayerAnimationDelegate;
+class LayerAnimationObserver;
 
 // Contains a collection of layer animation elements to be played one after
 // another. Although it has a similar interface to LayerAnimationElement, it is
 // not a LayerAnimationElement (i.e., it is not permitted to have a sequence in
 // a sequence). Sequences own their elements, and sequences are themselves owned
 // by a LayerAnimator.
 //
 // TODO(vollick) Create a 'blended' sequence for transitioning between
 // sequences.
 class COMPOSITOR_EXPORT LayerAnimationSequence {
@@ skipping 31 matching lines @@
 
   // Sequences can be looped indefinitely.
   void set_is_cyclic(bool is_cyclic) { is_cyclic_ = is_cyclic; }
   bool is_cyclic() const { return is_cyclic_; }
 
   // Returns true if this sequence has at least one element affecting a
   // property in |other|.
   bool HasCommonProperty(
       const LayerAnimationElement::AnimatableProperties& other) const;
 
+  // These functions are used for adding or removing observers from the observer
+  // list. The observers are notified when animations end.
+  void AddObserver(LayerAnimationObserver* observer);
+  void RemoveObserver(LayerAnimationObserver* observer);
+
+  // Notifies the observers that this sequence has ended.
+  void NotifyEnded();
+
  private:
   typedef std::vector<linked_ptr<LayerAnimationElement> > Elements;
 
   // The sum of the durations of all the elements in the sequence.
   base::TimeDelta duration_;
 
   // The union of all the properties modified by all elements in the sequence.
   LayerAnimationElement::AnimatableProperties properties_;
 
   // The elements in the sequence.
   Elements elements_;
 
   // True if the sequence should be looped forever.
   bool is_cyclic_;
 
   // These are used when animating to efficiently find the next element.
   size_t last_element_;
   base::TimeDelta last_start_;
 
+  // These parties are notified when layer animations end.
+  ObserverList<LayerAnimationObserver> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerAnimationSequence);
 };
 
 }  // namespace ui
 
 #endif  // UI_GFX_COMPOSITOR_LAYER_ANIMATION_SEQUENCE_H_