components/view_manager/animation_runner.h

   1 // Copyright 2014 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 COMPONENTS_VIEW_MANAGER_ANIMATION_RUNNER_H_
   6 #define COMPONENTS_VIEW_MANAGER_ANIMATION_RUNNER_H_
   7
   8 #include <algorithm>
   9 #include <map>
  10 #include <set>
  11 #include <vector>
  12
  13 #include "base/containers/scoped_ptr_hash_map.h"
  14 #include "base/observer_list.h"
  15 #include "base/time/time.h"
  16
  17 namespace mojo {
  18 class AnimationGroup;
  19 }
  20
  21 namespace view_manager {
  22
  23 class AnimationRunnerObserver;
  24 class ScheduledAnimationGroup;
  25 class ServerView;
  26
  27 // AnimationRunner is responsible for maintaing and running a set of animations.
  28 // The animations are represented as a set of AnimationGroups. New animations
  29 // are scheduled by way of Schedule(). A |view| may only have one animation
  30 // running at a time. Schedule()ing a new animation for a view already animating
  31 // implicitly cancels the current animation for the view. Animations progress
  32 // by way of the Tick() function.
  33 class AnimationRunner {
  34  public:
  35   using AnimationId = uint32_t;
  36   using ViewAndAnimationPair =
  37       std::pair<ServerView*, const mojo::AnimationGroup*>;
  38
  39   explicit AnimationRunner(base::TimeTicks now);
  40   ~AnimationRunner();
  41
  42   void AddObserver(AnimationRunnerObserver* observer);
  43   void RemoveObserver(AnimationRunnerObserver* observer);
  44
  45   // Schedules animations. If any of the groups are not valid no animations are
  46   // scheuled and 0 is returned. If there is an existing animation in progress
  47   // for any of the views it is canceled and any properties that were animating
  48   // but are no longer animating are set to their target value.
  49   AnimationId Schedule(const std::vector<ViewAndAnimationPair>& views,
  50                        base::TimeTicks now);
  51
  52   // Cancels an animation scheduled by an id that was previously returned from
  53   // Schedule().
  54   void CancelAnimation(AnimationId id);
  55
  56   // Cancels the animation scheduled for |view|. Does nothing if there is no
  57   // animation scheduled for |view|. This does not change |view|. That is, any
  58   // in progress animations are stopped.
  59   void CancelAnimationForView(ServerView* view);
  60
  61   // Advance the animations updating values appropriately.
  62   void Tick(base::TimeTicks time);
  63
  64   // Returns true if there are animations currently scheduled.
  65   bool HasAnimations() const { return !view_to_animation_map_.empty(); }
  66
  67   // Returns true if the animation identified by |id| is valid and animating.
  68   bool IsAnimating(AnimationId id) const {
  69     return id_to_views_map_.count(id) > 0;
  70   }
  71
  72   // Returns the views that are currently animating for |id|. Returns an empty
  73   // set if |id| does not identify a valid animation.
  74   std::set<ServerView*> GetViewsAnimating(AnimationId id) {
  75     return IsAnimating(id) ? id_to_views_map_.find(id)->second
  76                            : std::set<ServerView*>();
  77   }
  78
  79  private:
  80   enum CancelSource {
  81     // Cancel is the result of scheduling another animation for the view.
  82     CANCEL_SOURCE_SCHEDULE,
  83
  84     // Cancel originates from an explicit call to cancel.
  85     CANCEL_SOURCE_CANCEL,
  86   };
  87
  88   using ViewToAnimationMap =
  89       base::ScopedPtrHashMap<ServerView*, scoped_ptr<ScheduledAnimationGroup>>;
  90   using IdToViewsMap = std::map<AnimationId, std::set<ServerView*>>;
  91
  92   void CancelAnimationForViewImpl(ServerView* view, CancelSource source);
  93
  94   // Removes |view| from both |view_to_animation_map_| and |id_to_views_map_|.
  95   // Returns true if there are no more views animating with the animation id
  96   // the view is associated with.
  97   bool RemoveViewFromMaps(ServerView* view);
  98
  99   AnimationId next_id_;
 100
 101   base::TimeTicks last_tick_time_;
 102
 103   ObserverList<AnimationRunnerObserver> observers_;
 104
 105   ViewToAnimationMap view_to_animation_map_;
 106
 107   IdToViewsMap id_to_views_map_;
 108
 109   DISALLOW_COPY_AND_ASSIGN(AnimationRunner);
 110 };
 111
 112 }  // namespace view_manager
 113
 114 #endif  // COMPONENTS_VIEW_MANAGER_ANIMATION_RUNNER_H_