// 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_ELEMENT_ANIMATIONS_H_
#define CC_ANIMATION_ELEMENT_ANIMATIONS_H_

#include "base/containers/linked_list.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "cc/animation/animation_delegate.h"
#include "cc/animation/layer_animation_controller.h"
#include "cc/animation/layer_animation_value_provider.h"
#include "cc/base/cc_export.h"

namespace gfx {
class ScrollOffset;
class Transform;
}

namespace cc {

class AnimationHost;
class AnimationPlayer;
class FilterOperations;
class LayerAnimationController;
enum class LayerTreeType;

// An ElementAnimations owns a list of all AnimationPlayers, attached to
// the layer. Also, it owns LayerAnimationController instance (1:1
// relationship)
// ElementAnimations object redirects all events from LAC to the list
// of animation layers.
// This is a CC counterpart for blink::ElementAnimations (in 1:1 relationship).
// No pointer to/from respective blink::ElementAnimations object for now.
class CC_EXPORT ElementAnimations : public AnimationDelegate,
                                    public LayerAnimationValueProvider {
 public:
  static scoped_ptr<ElementAnimations> Create(AnimationHost* host);
  ~ElementAnimations() override;

  int layer_id() const {
    return layer_animation_controller_ ? layer_animation_controller_->id() : 0;
  }

  // Parent AnimationHost.
  AnimationHost* animation_host() { return animation_host_; }
  const AnimationHost* animation_host() const { return animation_host_; }

  LayerAnimationController* layer_animation_controller() const {
    return layer_animation_controller_.get();
  }

  void CreateLayerAnimationController(int layer_id);
  void DestroyLayerAnimationController();

  void LayerRegistered(int layer_id, LayerTreeType tree_type);
  void LayerUnregistered(int layer_id, LayerTreeType tree_type);

  bool has_active_value_observer_for_testing() const {
    return active_value_observer_;
  }
  bool has_pending_value_observer_for_testing() const {
    return pending_value_observer_;
  }

  void AddPlayer(AnimationPlayer* player);
  void RemovePlayer(AnimationPlayer* player);
  bool IsEmpty() const;

  typedef base::LinkedList<AnimationPlayer> PlayersList;
  typedef base::LinkNode<AnimationPlayer> PlayersListNode;
  const PlayersList& players_list() const { return *players_list_.get(); }

  void PushPropertiesTo(ElementAnimations* element_animations_impl);

 private:
  explicit ElementAnimations(AnimationHost* host);

  void SetFilterMutated(LayerTreeType tree_type,
                        const FilterOperations& filters);
  void SetOpacityMutated(LayerTreeType tree_type, float opacity);
  void SetTransformMutated(LayerTreeType tree_type,
                           const gfx::Transform& transform);
  void SetScrollOffsetMutated(LayerTreeType tree_type,
                              const gfx::ScrollOffset& scroll_offset);
  void SetTransformIsPotentiallyAnimatingChanged(LayerTreeType tree_type,
                                                 bool is_animating);

  void CreateActiveValueObserver();
  void DestroyActiveValueObserver();

  void CreatePendingValueObserver();
  void DestroyPendingValueObserver();

  // AnimationDelegate implementation
  void NotifyAnimationStarted(base::TimeTicks monotonic_time,
                              Animation::TargetProperty target_property,
                              int group) override;
  void NotifyAnimationFinished(base::TimeTicks monotonic_time,
                               Animation::TargetProperty target_property,
                               int group) override;

  // LayerAnimationValueProvider implementation.
  gfx::ScrollOffset ScrollOffsetForAnimation() const override;

  scoped_ptr<PlayersList> players_list_;

  class ValueObserver;
  scoped_ptr<ValueObserver> active_value_observer_;
  scoped_ptr<ValueObserver> pending_value_observer_;

  // LAC is owned by ElementAnimations (1:1 relationship).
  scoped_refptr<LayerAnimationController> layer_animation_controller_;
  AnimationHost* animation_host_;

  DISALLOW_COPY_AND_ASSIGN(ElementAnimations);
};

}  // namespace cc

#endif  // CC_ANIMATION_ELEMENT_ANIMATIONS_H_