cc/animation/worklet_animation_player.h

// Copyright 2017 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_WORKLET_ANIMATION_PLAYER_H_
#define CC_ANIMATION_WORKLET_ANIMATION_PLAYER_H_

#include "base/time/time.h"
#include "cc/animation/animation_export.h"
#include "cc/animation/animation_player.h"
#include "cc/animation/animation_ticker.h"

namespace cc {

class ScrollTimeline;

// A WorkletAnimationPlayer is an animations player that allows its animation
// timing to be controlled by an animator instance that is running in a
// AnimationWorkletGlobalScope.
class CC_ANIMATION_EXPORT WorkletAnimationPlayer final
    : public AnimationPlayer,
      AnimationTicker::AnimationTimeProvider {
 public:
  WorkletAnimationPlayer(int id,
                         const std::string& name,
                         std::unique_ptr<ScrollTimeline> scroll_timeline);
  static scoped_refptr<WorkletAnimationPlayer> Create(
      int id,
      const std::string& name,
      std::unique_ptr<ScrollTimeline> scroll_timeline);
  scoped_refptr<AnimationPlayer> CreateImplInstance() const override;

  const std::string& name() const { return name_; }
  const ScrollTimeline* scroll_timeline() const {
    return scroll_timeline_.get();
  }

  void SetLocalTime(base::TimeDelta local_time);
  bool IsWorkletAnimationPlayer() const override;

  void Tick(base::TimeTicks monotonic_time) override;

  // Returns the current time to be passed into the underlying AnimationWorklet.
  // The current time is based on the timeline associated with the animation.
  double CurrentTime(base::TimeTicks monotonic_time,
                     const ScrollTree& scroll_tree);

  // AnimationTicker::AnimationTimeProvider:
  base::TimeTicks GetTimeForAnimation(
      const Animation& animation) const override;

  void PushPropertiesTo(AnimationPlayer* animation_player_impl) override;

 private:
  ~WorkletAnimationPlayer() override;

  std::string name_;

  // The ScrollTimeline associated with the underlying animation. If null, the
  // animation is based on a DocumentTimeline.
  //
  // TODO(crbug.com/780148): A WorkletAnimationPlayer should own an
  // AnimationTimeline which must exist but can either be a DocumentTimeline,
  // ScrollTimeline, or some other future implementation.
  std::unique_ptr<ScrollTimeline> scroll_timeline_;

  base::TimeDelta local_time_;
};

}  // namespace cc

#endif  // CC_ANIMATION_WORKLET_ANIMATION_PLAYER_H_