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      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     BackgroundColor,
     46     ScrollOffset,
     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_
    193