cc/animation/animation.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_ANIMATION_ANIMATION_H_
   6 #define CC_ANIMATION_ANIMATION_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "cc/base/cc_export.h"
  11
  12 namespace cc {
  13
  14 class AnimationCurve;
  15
  16 // An Animation contains all the state required to play an AnimationCurve.
  17 // Specifically, the affected property, the run state (paused, finished, etc.),
  18 // loop count, last pause time, and the total time spent paused.
  19 class CC_EXPORT Animation {
  20  public:
  21   // Animations begin in the 'WaitingForTargetAvailability' state. An Animation
  22   // waiting for target availibility will run as soon as its target property
  23   // is free (and all the animations animating with it are also able to run).
  24   // When this time arrives, the controller will move the animation into the
  25   // Starting state, and then into the Running state. Running animations may
  26   // toggle between Running and Paused, and may be stopped by moving into either
  27   // the Aborted or Finished states. A Finished animation was allowed to run to
  28   // completion, but an Aborted animation was not.
  29   enum RunState {
  30     WaitingForTargetAvailability = 0,
  31     WaitingForDeletion,
  32     Starting,
  33     Running,
  34     Paused,
  35     Finished,
  36     Aborted,
  37     // This sentinel must be last.
  38     RunStateEnumSize
  39   };
  40
  41   enum TargetProperty {
  42     Transform = 0,
  43     Opacity,
  44     Filter,
  45     ScrollOffset,
  46     BackgroundColor,
  47     // This sentinel must be last.
  48     TargetPropertyEnumSize
  49   };
  50
  51   static scoped_ptr<Animation> Create(scoped_ptr<AnimationCurve> curve,
  52                                       int animation_id,
  53                                       int group_id,
  54                                       TargetProperty target_property);
  55
  56   virtual ~Animation();
  57
  58   int id() const { return id_; }
  59   int group() const { return group_; }
  60   TargetProperty target_property() const { return target_property_; }
  61
  62   RunState run_state() const { return run_state_; }
  63   void SetRunState(RunState run_state, double monotonic_time);
  64
  65   // This is the number of times that the animation will play. If this
  66   // value is zero the animation will not play. If it is negative, then
  67   // the animation will loop indefinitely.
  68   int iterations() const { return iterations_; }
  69   void set_iterations(int n) { iterations_ = n; }
  70
  71   double start_time() const { return start_time_; }
  72   void set_start_time(double monotonic_time) { start_time_ = monotonic_time; }
  73   bool has_set_start_time() const { return !!start_time_; }
  74
  75   double time_offset() const { return time_offset_; }
  76   void set_time_offset(double monotonic_time) { time_offset_ = monotonic_time; }
  77
  78   void Suspend(double monotonic_time);
  79   void Resume(double monotonic_time);
  80
  81   // If alternates_direction is true, on odd numbered iterations we reverse the
  82   // curve.
  83   bool alternates_direction() const { return alternates_direction_; }
  84   void set_alternates_direction(bool alternates) {
  85     alternates_direction_ = alternates;
  86   }
  87
  88   bool IsFinishedAt(double monotonic_time) const;
  89   bool is_finished() const {
  90     return run_state_ == Finished ||
  91         run_state_ == Aborted ||
  92         run_state_ == WaitingForDeletion;
  93   }
  94
  95   AnimationCurve* curve() { return curve_.get(); }
  96   const AnimationCurve* curve() const { return curve_.get(); }
  97
  98   // If this is true, even if the animation is running, it will not be tickable
  99   // until it is given a start time. This is true for animations running on the
 100   // main thread.
 101   bool needs_synchronized_start_time() const {
 102     return needs_synchronized_start_time_;
 103   }
 104   void set_needs_synchronized_start_time(bool needs_synchronized_start_time) {
 105     needs_synchronized_start_time_ = needs_synchronized_start_time;
 106   }
 107
 108   // This is true for animations running on the main thread when the Finished
 109   // event sent by the corresponding impl animation has been received.
 110   bool received_finished_event() const {
 111     return received_finished_event_;
 112   }
 113   void set_received_finished_event(bool received_finished_event) {
 114     received_finished_event_ = received_finished_event;
 115   }
 116
 117   // Takes the given absolute time, and using the start time and the number
 118   // of iterations, returns the relative time in the current iteration.
 119   double TrimTimeToCurrentIteration(double monotonic_time) const;
 120
 121   scoped_ptr<Animation> Clone() const;
 122   scoped_ptr<Animation> CloneAndInitialize(RunState initial_run_state,
 123                                            double start_time) const;
 124   bool is_controlling_instance() const { return is_controlling_instance_; }
 125
 126   void PushPropertiesTo(Animation* other) const;
 127
 128   void set_is_impl_only(bool is_impl_only) { is_impl_only_ = is_impl_only; }
 129   bool is_impl_only() const { return is_impl_only_; }
 130
 131  private:
 132   Animation(scoped_ptr<AnimationCurve> curve,
 133             int animation_id,
 134             int group_id,
 135             TargetProperty target_property);
 136
 137   scoped_ptr<AnimationCurve> curve_;
 138
 139   // IDs are not necessarily unique.
 140   int id_;
 141
 142   // Animations that must be run together are called 'grouped' and have the same
 143   // group id. Grouped animations are guaranteed to start at the same time and
 144   // no other animations may animate any of the group's target properties until
 145   // all animations in the group have finished animating. Note: an active
 146   // animation's group id and target property uniquely identify that animation.
 147   int group_;
 148
 149   TargetProperty target_property_;
 150   RunState run_state_;
 151   int iterations_;
 152   double start_time_;
 153   bool alternates_direction_;
 154
 155   // The time offset effectively pushes the start of the animation back in time.
 156   // This is used for resuming paused animations -- an animation is added with a
 157   // non-zero time offset, causing the animation to skip ahead to the desired
 158   // point in time.
 159   double time_offset_;
 160
 161   bool needs_synchronized_start_time_;
 162   bool received_finished_event_;
 163
 164   // When an animation is suspended, it behaves as if it is paused and it also
 165   // ignores all run state changes until it is resumed. This is used for testing
 166   // purposes.
 167   bool suspended_;
 168
 169   // These are used in TrimTimeToCurrentIteration to account for time
 170   // spent while paused. This is not included in AnimationState since it
 171   // there is absolutely no need for clients of this controller to know
 172   // about these values.
 173   double pause_time_;
 174   double total_paused_time_;
 175
 176   // Animations lead dual lives. An active animation will be conceptually owned
 177   // by two controllers, one on the impl thread and one on the main. In reality,
 178   // there will be two separate Animation instances for the same animation. They
 179   // will have the same group id and the same target property (these two values
 180   // uniquely identify an animation). The instance on the impl thread is the
 181   // instance that ultimately controls the values of the animating layer and so
 182   // we will refer to it as the 'controlling instance'.
 183   bool is_controlling_instance_;
 184
 185   bool is_impl_only_;
 186
 187   DISALLOW_COPY_AND_ASSIGN(Animation);
 188 };
 189
 190 }  // namespace cc
 191
 192 #endif  // CC_ANIMATION_ANIMATION_H_