CC Animations: Establish AnimationHost, AnimationTimeline and AnimationPlayer

cc/animation/animation_host.h

+// Copyright 2015 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_HOST_H_
+#define CC_ANIMATION_ANIMATION_HOST_H_
+
+#include <vector>
+
+#include "base/containers/hash_tables.h"
+#include "base/containers/linked_list.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/base/cc_export.h"
+#include "cc/trees/layer_tree_mutators_client.h"
+
+namespace cc {
+
+class AnimationPlayer;
+class AnimationRegistrar;
+class AnimationTimeline;
+class LayerAnimationController;
+class LayerTreeHost;
+
+enum class ThreadInstance { MAIN, IMPL };

[Ian Vollick, 2015/06/22 13:58:39]

This looks much nicer. Thanks!

+
+typedef std::vector<scoped_refptr<AnimationTimeline>> AnimationTimelineList;
+
+// An AnimationHost contains all the state required to play animations.
+// Specifically, it owns all the AnimationTimelines objects.
+// There is just one AnimationHost for LayerTreeHost on main renderer thread
+// and just one AnimationHost for LayerTreeHostImpl on impl thread.
+// We synchronize them during the commit process in a one-way data flow process
+// (PushPropertiesTo).
+// An AnimationHost talks to its correspondent LayerTreeHost via
+// LayerTreeMutatorsClient interface.
+// AnimationHost has it's own instance of AnimationRegistrar,
+// we want to merge AnimationRegistrar into AnimationHost.
+class CC_EXPORT AnimationHost {
+ public:
+  static scoped_ptr<AnimationHost> Create(ThreadInstance thread_instance);
+  virtual ~AnimationHost();
+
+  void AddAnimationTimeline(scoped_refptr<AnimationTimeline> timeline);
+  void RemoveAnimationTimeline(scoped_refptr<AnimationTimeline> timeline);
+  AnimationTimeline* GetTimelineById(int timeline_id) const;
+
+  void ClearTimelines();
+
+  void RegisterLayer(int layer_id, LayerTreeType tree_type);
+  void UnregisterLayer(int layer_id, LayerTreeType tree_type);
+
+  void RegisterPlayerForLayer(int layer_id, AnimationPlayer* player);
+  void UnregisterPlayerForLayer(int layer_id, AnimationPlayer* player);
+
+  typedef base::LinkedList<AnimationPlayer> PlayersList;
+  PlayersList* GetPlayersForLayerId(int layer_id) const;
+
+  // Parent LayerTreeHost or LayerTreeHostImpl.
+  LayerTreeMutatorsClient* layer_tree_mutators_client() {
+    return layer_tree_mutators_client_;
+  }
+  const LayerTreeMutatorsClient* layer_tree_mutators_client() const {
+    return layer_tree_mutators_client_;
+  }
+  void SetLayerTreeMutatorsClient(LayerTreeMutatorsClient* client);
+
+  void SetNeedsCommit();
+
+  void PushPropertiesTo(AnimationHost* host_impl);
+
+  AnimationRegistrar* animation_registrar() const {
+    return animation_registrar_.get();
+  }
+
+ private:
+  explicit AnimationHost(ThreadInstance thread_instance);
+
+  LayerAnimationController* GetControllerForLayerId(int layer_id) const;
+
+  bool EnsureListPlayersShareController(const PlayersList& players_list) const;
+
+  void PushTimelinesToImplThread(AnimationHost* host_impl) const;
+  void RemoveTimelinesFromImplThread(AnimationHost* host_impl) const;
+  void PushPropertiesToImplThread(AnimationHost* host_impl);
+
+  void EraseTimelines(AnimationTimelineList::iterator begin,
+                      AnimationTimelineList::iterator end);
+
+  // TODO(loyso): For now AnimationPlayers share LayerAnimationController object
+  // if they are attached to the same layer. Introduce LayersAnimations object
+  // to make AnimationPlayers-to-Layers relationship explicit (many-to-many).
+  // (a CC counterpart for blink::ElementAnimations. Note that Element can
+  // contain many Layers).
+  typedef base::hash_map<int, PlayersList*> LayerToPlayersMap;

[Ian Vollick, 2015/06/22 13:58:39]

The PlayersList is a good idea -- it does make things much clearer.

+  LayerToPlayersMap layer_to_players_map_;
+
+  AnimationTimelineList timelines_;
+  scoped_ptr<AnimationRegistrar> animation_registrar_;
+  LayerTreeMutatorsClient* layer_tree_mutators_client_;
+
+  const ThreadInstance thread_instance_;
+
+  DISALLOW_COPY_AND_ASSIGN(AnimationHost);
+};
+
+}  // namespace cc
+
+#endif  // CC_ANIMATION_ANIMATION_HOST_H_