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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 "base/time/time.h"
     11 #include "cc/base/cc_export.h"
     12 
     13 namespace cc {
     14 
     15 class AnimationCurve;
     16 
     17 // An Animation contains all the state required to play an AnimationCurve.
     18 // Specifically, the affected property, the run state (paused, finished, etc.),
     19 // loop count, last pause time, and the total time spent paused.
     20 class CC_EXPORT Animation {
     21  public:
     22   // Animations begin in the 'WaitingForTargetAvailability' state. An Animation
     23   // waiting for target availibility will run as soon as its target property
     24   // is free (and all the animations animating with it are also able to run).
     25   // When this time arrives, the controller will move the animation into the
     26   // Starting state, and then into the Running state. Running animations may
     27   // toggle between Running and Paused, and may be stopped by moving into either
     28   // the Aborted or Finished states. A Finished animation was allowed to run to
     29   // completion, but an Aborted animation was not.
     30   enum RunState {
     31     WaitingForTargetAvailability = 0,
     32     WaitingForDeletion,
     33     Starting,
     34     Running,
     35     Paused,
     36     Finished,
     37     Aborted,
     38     // This sentinel must be last.
     39     RunStateEnumSize
     40   };
     41 
     42   enum TargetProperty {
     43     Transform = 0,
     44     Opacity,
     45     Filter,
     46     ScrollOffset,
     47     BackgroundColor,
     48     // This sentinel must be last.
     49     TargetPropertyEnumSize
     50   };
     51 
     52   enum Direction { Normal, Reverse, Alternate, AlternateReverse };
     53 
     54   static scoped_ptr<Animation> Create(scoped_ptr<AnimationCurve> curve,
     55                                       int animation_id,
     56                                       int group_id,
     57                                       TargetProperty target_property);
     58 
     59   virtual ~Animation();
     60 
     61   int id() const { return id_; }
     62   int group() const { return group_; }
     63   TargetProperty target_property() const { return target_property_; }
     64 
     65   RunState run_state() const { return run_state_; }
     66   void SetRunState(RunState run_state, base::TimeTicks monotonic_time);
     67 
     68   // This is the number of times that the animation will play. If this
     69   // value is zero the animation will not play. If it is negative, then
     70   // the animation will loop indefinitely.
     71   int iterations() const { return iterations_; }
     72   void set_iterations(int n) { iterations_ = n; }
     73 
     74   base::TimeTicks start_time() const { return start_time_; }
     75 
     76   void set_start_time(base::TimeTicks monotonic_time) {
     77     start_time_ = monotonic_time;
     78   }
     79   bool has_set_start_time() const { return !start_time_.is_null(); }
     80 
     81   base::TimeDelta time_offset() const { return time_offset_; }
     82   void set_time_offset(base::TimeDelta monotonic_time) {
     83     time_offset_ = monotonic_time;
     84   }
     85 
     86   void Suspend(base::TimeTicks monotonic_time);
     87   void Resume(base::TimeTicks monotonic_time);
     88 
     89   Direction direction() { return direction_; }
     90   void set_direction(Direction direction) { direction_ = direction; }
     91 
     92   bool IsFinishedAt(base::TimeTicks monotonic_time) const;
     93   bool is_finished() const {
     94     return run_state_ == Finished ||
     95         run_state_ == Aborted ||
     96         run_state_ == WaitingForDeletion;
     97   }
     98 
     99   AnimationCurve* curve() { return curve_.get(); }
    100   const AnimationCurve* curve() const { return curve_.get(); }
    101 
    102   // If this is true, even if the animation is running, it will not be tickable
    103   // until it is given a start time. This is true for animations running on the
    104   // main thread.
    105   bool needs_synchronized_start_time() const {
    106     return needs_synchronized_start_time_;
    107   }
    108   void set_needs_synchronized_start_time(bool needs_synchronized_start_time) {
    109     needs_synchronized_start_time_ = needs_synchronized_start_time;
    110   }
    111 
    112   // This is true for animations running on the main thread when the Finished
    113   // event sent by the corresponding impl animation has been received.
    114   bool received_finished_event() const {
    115     return received_finished_event_;
    116   }
    117   void set_received_finished_event(bool received_finished_event) {
    118     received_finished_event_ = received_finished_event;
    119   }
    120 
    121   // Takes the given absolute time, and using the start time and the number
    122   // of iterations, returns the relative time in the current iteration.
    123   double TrimTimeToCurrentIteration(base::TimeTicks monotonic_time) const;
    124 
    125   scoped_ptr<Animation> CloneAndInitialize(RunState initial_run_state) const;
    126 
    127   bool is_controlling_instance() const { return is_controlling_instance_; }
    128 
    129   void PushPropertiesTo(Animation* other) const;
    130 
    131   void set_is_impl_only(bool is_impl_only) { is_impl_only_ = is_impl_only; }
    132   bool is_impl_only() const { return is_impl_only_; }
    133 
    134   void set_affects_active_observers(bool affects_active_observers) {
    135     affects_active_observers_ = affects_active_observers;
    136   }
    137   bool affects_active_observers() const { return affects_active_observers_; }
    138 
    139   void set_affects_pending_observers(bool affects_pending_observers) {
    140     affects_pending_observers_ = affects_pending_observers;
    141   }
    142   bool affects_pending_observers() const { return affects_pending_observers_; }
    143 
    144  private:
    145   Animation(scoped_ptr<AnimationCurve> curve,
    146             int animation_id,
    147             int group_id,
    148             TargetProperty target_property);
    149 
    150   scoped_ptr<AnimationCurve> curve_;
    151 
    152   // IDs are not necessarily unique.
    153   int id_;
    154 
    155   // Animations that must be run together are called 'grouped' and have the same
    156   // group id. Grouped animations are guaranteed to start at the same time and
    157   // no other animations may animate any of the group's target properties until
    158   // all animations in the group have finished animating. Note: an active
    159   // animation's group id and target property uniquely identify that animation.
    160   int group_;
    161 
    162   TargetProperty target_property_;
    163   RunState run_state_;
    164   int iterations_;
    165   base::TimeTicks start_time_;
    166   Direction direction_;
    167 
    168   // The time offset effectively pushes the start of the animation back in time.
    169   // This is used for resuming paused animations -- an animation is added with a
    170   // non-zero time offset, causing the animation to skip ahead to the desired
    171   // point in time.
    172   base::TimeDelta time_offset_;
    173 
    174   bool needs_synchronized_start_time_;
    175   bool received_finished_event_;
    176 
    177   // When an animation is suspended, it behaves as if it is paused and it also
    178   // ignores all run state changes until it is resumed. This is used for testing
    179   // purposes.
    180   bool suspended_;
    181 
    182   // These are used in TrimTimeToCurrentIteration to account for time
    183   // spent while paused. This is not included in AnimationState since it
    184   // there is absolutely no need for clients of this controller to know
    185   // about these values.
    186   base::TimeTicks pause_time_;
    187   base::TimeDelta total_paused_time_;
    188 
    189   // Animations lead dual lives. An active animation will be conceptually owned
    190   // by two controllers, one on the impl thread and one on the main. In reality,
    191   // there will be two separate Animation instances for the same animation. They
    192   // will have the same group id and the same target property (these two values
    193   // uniquely identify an animation). The instance on the impl thread is the
    194   // instance that ultimately controls the values of the animating layer and so
    195   // we will refer to it as the 'controlling instance'.
    196   bool is_controlling_instance_;
    197 
    198   bool is_impl_only_;
    199 
    200   // When pushed from a main-thread controller to a compositor-thread
    201   // controller, an animation will initially only affect pending observers
    202   // (corresponding to layers in the pending tree). Animations that only
    203   // affect pending observers are able to reach the Starting state and tick
    204   // pending observers, but cannot proceed any further and do not tick active
    205   // observers. After activation, such animations affect both kinds of observers
    206   // and are able to proceed past the Starting state. When the removal of
    207   // an animation is pushed from a main-thread controller to a
    208   // compositor-thread controller, this initially only makes the animation
    209   // stop affecting pending observers. After activation, such animations no
    210   // longer affect any observers, and are deleted.
    211   bool affects_active_observers_;
    212   bool affects_pending_observers_;
    213 
    214   DISALLOW_COPY_AND_ASSIGN(Animation);
    215 };
    216 
    217 }  // namespace cc
    218 
    219 #endif  // CC_ANIMATION_ANIMATION_H_
    220