/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_AnimationTimeline_h

#define mozilla_dom_AnimationTimeline_h

#include "nsISupports.h"

#include "nsWrapperCache.h"

#include "nsCycleCollectionParticipant.h"

#include "js/TypeDecls.h"

#include "mozilla/AnimationUtils.h"

#include "mozilla/Attributes.h"

#include "nsHashKeys.h"

#include "nsIGlobalObject.h"

#include "nsTHashtable.h"

// GetCurrentTime is defined in winbase.h as zero argument macro forwarding to

// GetTickCount().

#ifdef GetCurrentTime

#undef GetCurrentTime

#endif

class nsIDocument;

namespace mozilla {

namespace dom {

class Animation;

class AnimationTimeline

  : public nsISupports

  , public nsWrapperCache

{

public:

  explicit AnimationTimeline(nsIGlobalObject* aWindow)

    : mWindow(aWindow)

  {

    MOZ_ASSERT(mWindow);

  }

protected:

  virtual ~AnimationTimeline()

  {

    mAnimationOrder.clear();

  }

public:

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(AnimationTimeline)

  nsIGlobalObject* GetParentObject() const { return mWindow; }

  // AnimationTimeline methods

  virtual Nullable<TimeDuration> GetCurrentTime() const = 0;

  // Wrapper functions for AnimationTimeline DOM methods when called from

  // script.

  Nullable<double> GetCurrentTimeAsDouble() const {

    return AnimationUtils::TimeDurationToDouble(GetCurrentTime());

  }

  TimeStamp GetCurrentTimeAsTimeStamp() const {

    Nullable<TimeDuration> currentTime = GetCurrentTime();

    return !currentTime.IsNull()

      ? ToTimeStamp(currentTime.Value())

      : TimeStamp();

  }

  /**

   * Returns true if the times returned by GetCurrentTime() are convertible

   * to and from wallclock-based TimeStamp (e.g. from TimeStamp::Now()) values

   * using ToTimelineTime() and ToTimeStamp().

   *

   * Typically this is true, but it will be false in the case when this

   * timeline has no refresh driver or is tied to a refresh driver under test

   * control.

   */

  virtual bool TracksWallclockTime() const = 0;

  /**

   * Converts a TimeStamp to the equivalent value in timeline time.

   * Note that when TracksWallclockTime() is false, there is no correspondence

   * between timeline time and wallclock time. In such a case, passing a

   * timestamp from TimeStamp::Now() to this method will not return a

   * meaningful result.

   */

  virtual Nullable<TimeDuration> ToTimelineTime(const TimeStamp&

                                                  aTimeStamp) const = 0;

  virtual TimeStamp ToTimeStamp(const TimeDuration& aTimelineTime) const = 0;

  /**

   * Inform this timeline that |aAnimation| which is or was observing the

   * timeline, has been updated. This serves as both the means to associate

   * AND disassociate animations with a timeline. The timeline itself will

   * determine if it needs to begin, continue or stop tracking this animation.

   */

  virtual void NotifyAnimationUpdated(Animation& aAnimation);

  /**

   * Returns true if any CSS animations, CSS transitions or Web animations are

   * currently associated with this timeline.  As soon as an animation is

   * applied to an element it is associated with the timeline even if it has a

   * delayed start, so this includes animations that may not be active for some

   * time.

   */

  bool HasAnimations() const {

    return !mAnimations.IsEmpty();

  }

  virtual void RemoveAnimation(Animation* aAnimation);

  virtual nsIDocument* GetDocument() const = 0;

protected:

  nsCOMPtr<nsIGlobalObject> mWindow;

  // Animations observing this timeline

  //

  // We store them in (a) a hashset for quick lookup, and (b) an array

  // to maintain a fixed sampling order.

  //

  // The hashset keeps a strong reference to each animation since

  // dealing with addref/release with LinkedList is difficult.

  typedef nsTHashtable<nsRefPtrHashKey<dom::Animation>> AnimationSet;

  AnimationSet mAnimations;

  LinkedList<dom::Animation> mAnimationOrder;

};

} // namespace dom

} // namespace mozilla

#endif // mozilla_dom_AnimationTimeline_h