element_animations.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_ELEMENT_ANIMATIONS_H_
#define CC_ANIMATION_ELEMENT_ANIMATIONS_H_

#include <memory>
#include <vector>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/observer_list.h"
#include "base/time/time.h"
#include "cc/base/cc_export.h"
#include "cc/trees/element_id.h"
#include "cc/trees/property_animation_state.h"
#include "cc/trees/target_property.h"
#include "ui/gfx/geometry/scroll_offset.h"
#include "ui/gfx/transform.h"

namespace gfx {
class BoxF;
}

namespace cc {

class AnimationEvents;
class AnimationHost;
class AnimationPlayer;
class FilterOperations;
enum class ElementListType;
struct AnimationEvent;

// An ElementAnimations owns a list of all AnimationPlayers, attached to
// the element.
// 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 base::RefCounted<ElementAnimations> {
 public:
  static scoped_refptr<ElementAnimations> Create();

  ElementId element_id() const { return element_id_; }
  void SetElementId(ElementId element_id);

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

  void InitAffectedElementTypes();
  void ClearAffectedElementTypes();

  void ElementRegistered(ElementId element_id, ElementListType list_type);
  void ElementUnregistered(ElementId element_id, ElementListType list_type);

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

  typedef base::ObserverList<AnimationPlayer> PlayersList;
  const PlayersList& players_list() const { return players_list_; }

  // Ensures that the list of active animations on the main thread and the impl
  // thread are kept in sync. This function does not take ownership of the impl
  // thread ElementAnimations.
  void PushPropertiesTo(
      scoped_refptr<ElementAnimations> element_animations_impl);

  void Animate(base::TimeTicks monotonic_time);

  void UpdateState(bool start_ready_animations, AnimationEvents* events);

  // Make animations affect active elements if and only if they affect
  // pending elements. Any animations that no longer affect any elements
  // are deleted.
  void ActivateAnimations();

  // Returns true if there are any animations that have neither finished nor
  // aborted.
  bool HasActiveAnimation() const;

  // Returns true if there are any animations at all to process.
  bool HasAnyAnimation() const;

  bool HasAnyAnimationTargetingProperty(TargetProperty::Type property) const;

  // Returns true if there is an animation that is either currently animating
  // the given property or scheduled to animate this property in the future, and
  // that affects the given tree type.
  bool IsPotentiallyAnimatingProperty(TargetProperty::Type target_property,
                                      ElementListType list_type) const;

  // Returns true if there is an animation that is currently animating the given
  // property and that affects the given tree type.
  bool IsCurrentlyAnimatingProperty(TargetProperty::Type target_property,
                                    ElementListType list_type) const;

  void NotifyAnimationStarted(const AnimationEvent& event);
  void NotifyAnimationFinished(const AnimationEvent& event);
  void NotifyAnimationAborted(const AnimationEvent& event);
  void NotifyAnimationPropertyUpdate(const AnimationEvent& event);
  void NotifyAnimationTakeover(const AnimationEvent& event);

  bool has_element_in_active_list() const {
    return has_element_in_active_list_;
  }
  bool has_element_in_pending_list() const {
    return has_element_in_pending_list_;
  }
  bool has_element_in_any_list() const {
    return has_element_in_active_list_ || has_element_in_pending_list_;
  }

  void set_has_element_in_active_list(bool has_element_in_active_list) {
    has_element_in_active_list_ = has_element_in_active_list;
  }
  void set_has_element_in_pending_list(bool has_element_in_pending_list) {
    has_element_in_pending_list_ = has_element_in_pending_list;
  }

  bool HasFilterAnimationThatInflatesBounds() const;
  bool HasTransformAnimationThatInflatesBounds() const;
  bool HasAnimationThatInflatesBounds() const {
    return HasTransformAnimationThatInflatesBounds() ||
           HasFilterAnimationThatInflatesBounds();
  }

  bool FilterAnimationBoundsForBox(const gfx::BoxF& box,
                                   gfx::BoxF* bounds) const;
  bool TransformAnimationBoundsForBox(const gfx::BoxF& box,
                                      gfx::BoxF* bounds) const;

  bool HasOnlyTranslationTransforms(ElementListType list_type) const;

  bool AnimationsPreserveAxisAlignment() const;

  // Sets |start_scale| to the maximum of starting animation scale along any
  // dimension at any destination in active animations. Returns false if the
  // starting scale cannot be computed.
  bool AnimationStartScale(ElementListType list_type, float* start_scale) const;

  // Sets |max_scale| to the maximum scale along any dimension at any
  // destination in active animations. Returns false if the maximum scale cannot
  // be computed.
  bool MaximumTargetScale(ElementListType list_type, float* max_scale) const;

  // When a scroll animation is removed on the main thread, its compositor
  // thread counterpart continues producing scroll deltas until activation.
  // These scroll deltas need to be cleared at activation, so that the active
  // element's scroll offset matches the offset provided by the main thread
  // rather than a combination of this offset and scroll deltas produced by
  // the removed animation. This is to provide the illusion of synchronicity to
  // JS that simultaneously removes an animation and sets the scroll offset.
  bool scroll_offset_animation_was_interrupted() const {
    return scroll_offset_animation_was_interrupted_;
  }
  void SetScrollOffsetAnimationWasInterrupted();

  void SetNeedsPushProperties();
  bool needs_push_properties() const { return needs_push_properties_; }

  void UpdateClientAnimationState();
  void SetNeedsUpdateImplClientState();

  void UpdateActivationNormal();

  void NotifyClientOpacityAnimated(float opacity,
                                   bool notify_active_elements,
                                   bool notify_pending_elements);
  void NotifyClientTransformAnimated(const gfx::Transform& transform,
                                     bool notify_active_elements,
                                     bool notify_pending_elements);
  void NotifyClientFilterAnimated(const FilterOperations& filter,
                                  bool notify_active_elements,
                                  bool notify_pending_elements);
  void NotifyClientScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset,
                                        bool notify_active_elements,
                                        bool notify_pending_elements);
  gfx::ScrollOffset ScrollOffsetForAnimation() const;

 private:
  friend class base::RefCounted<ElementAnimations>;

  ElementAnimations();
  ~ElementAnimations();

  enum class ActivationType { NORMAL, FORCE };
  void UpdateActivation(ActivationType type);

  void OnFilterAnimated(ElementListType list_type,
                        const FilterOperations& filters);
  void OnOpacityAnimated(ElementListType list_type, float opacity);
  void OnTransformAnimated(ElementListType list_type,
                           const gfx::Transform& transform);
  void OnScrollOffsetAnimated(ElementListType list_type,
                              const gfx::ScrollOffset& scroll_offset);

  static TargetProperties GetPropertiesMaskForAnimationState();

  PlayersList players_list_;
  AnimationHost* animation_host_;
  ElementId element_id_;

  // This is used to ensure that we don't spam the animation host.
  bool is_active_;

  base::TimeTicks last_tick_time_;

  bool has_element_in_active_list_;
  bool has_element_in_pending_list_;

  bool scroll_offset_animation_was_interrupted_;

  bool needs_push_properties_;

  PropertyAnimationState active_state_;
  PropertyAnimationState pending_state_;

  bool needs_update_impl_client_state_;

  DISALLOW_COPY_AND_ASSIGN(ElementAnimations);
};

}  // namespace cc

#endif  // CC_ANIMATION_ELEMENT_ANIMATIONS_H_