Handle direction control in compositor Animations

cc/animation/animation.h

 // Copyright 2012 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 CC_ANIMATION_ANIMATION_H_
 #define CC_ANIMATION_ANIMATION_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
@@ skipping 30 matching lines @@
   enum TargetProperty {
     Transform = 0,
     Opacity,
     Filter,
     ScrollOffset,
     BackgroundColor,
     // This sentinel must be last.
     TargetPropertyEnumSize
   };
 
+  enum Direction { Normal, Reverse, Alternate, AlternateReverse };
+
   static scoped_ptr<Animation> Create(scoped_ptr<AnimationCurve> curve,
                                       int animation_id,
                                       int group_id,
                                       TargetProperty target_property);
 
   virtual ~Animation();
 
   int id() const { return id_; }
   int group() const { return group_; }
   TargetProperty target_property() const { return target_property_; }
@@ skipping 10 matching lines @@
   double start_time() const { return start_time_; }
   void set_start_time(double monotonic_time) { start_time_ = monotonic_time; }
   bool has_set_start_time() const { return !!start_time_; }
 
   double time_offset() const { return time_offset_; }
   void set_time_offset(double monotonic_time) { time_offset_ = monotonic_time; }
 
   void Suspend(double monotonic_time);
   void Resume(double monotonic_time);
 
-  // If alternates_direction is true, on odd numbered iterations we reverse the
-  // curve.
-  bool alternates_direction() const { return alternates_direction_; }
-  void set_alternates_direction(bool alternates) {
-    alternates_direction_ = alternates;
-  }
+  Direction direction() { return direction_; }
+  void set_direction(Direction direction) { direction_ = direction; }
 
   bool IsFinishedAt(double monotonic_time) const;
   bool is_finished() const {
     return run_state_ == Finished ||
         run_state_ == Aborted ||
         run_state_ == WaitingForDeletion;
   }
 
   AnimationCurve* curve() { return curve_.get(); }
   const AnimationCurve* curve() const { return curve_.get(); }
@@ skipping 46 matching lines @@
   // group id. Grouped animations are guaranteed to start at the same time and
   // no other animations may animate any of the group's target properties until
   // all animations in the group have finished animating. Note: an active
   // animation's group id and target property uniquely identify that animation.
   int group_;
 
   TargetProperty target_property_;
   RunState run_state_;
   int iterations_;
   double start_time_;
-  bool alternates_direction_;
+  Direction direction_;
 
   // The time offset effectively pushes the start of the animation back in time.
   // This is used for resuming paused animations -- an animation is added with a
   // non-zero time offset, causing the animation to skip ahead to the desired
   // point in time.
   double time_offset_;
 
   bool needs_synchronized_start_time_;
   bool received_finished_event_;
 
@@ skipping 19 matching lines @@
   bool is_controlling_instance_;
 
   bool is_impl_only_;
 
   DISALLOW_COPY_AND_ASSIGN(Animation);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ANIMATION_H_