dom/animation/AnimationTimeline.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_AnimationTimeline_h
   8 #define mozilla_dom_AnimationTimeline_h
   9
  10 #include "nsISupports.h"
  11 #include "nsWrapperCache.h"
  12 #include "nsCycleCollectionParticipant.h"
  13 #include "mozilla/AnimationUtils.h"
  14 #include "nsHashKeys.h"
  15 #include "nsIGlobalObject.h"
  16 #include "nsTHashSet.h"
  17
  18 namespace mozilla::dom {
  19
  20 class Animation;
  21 class Document;
  22 class ScrollTimeline;
  23
  24 class AnimationTimeline : public nsISupports, public nsWrapperCache {
  25  public:
  26   explicit AnimationTimeline(nsIGlobalObject* aWindow,
  27                              RTPCallerType aRTPCallerType);
  28
  29   // We want to synchronize non-geometric animations that are started at the
  30   // same time as geometric ones (e.g., transform animations that are started at
  31   // the same time as a width animation).
  32   //
  33   // We only synchronize animations with animations, and transitions with
  34   // transitions.
  35   //
  36   // TODO: Remove all this once bug 1540906 rides the trains.
  37   struct TickState {
  38     AutoTArray<Animation*, 8> mStartedAnimations;
  39     AutoTArray<Animation*, 8> mStartedTransitions;
  40     bool mStartedAnyGeometricTransition = false;
  41     bool mStartedAnyGeometricAnimation = false;
  42   };
  43
  44  protected:
  45   virtual ~AnimationTimeline();
  46
  47   // Tick animations and may remove them from the list if we don't need to tick
  48   // it. Return true if any animations need to be ticked.
  49   bool Tick(TickState&);
  50
  51  public:
  52   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  53   NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(AnimationTimeline)
  54
  55   nsIGlobalObject* GetParentObject() const { return mWindow; }
  56
  57   // AnimationTimeline methods
  58   virtual Nullable<TimeDuration> GetCurrentTimeAsDuration() const = 0;
  59
  60   // Wrapper functions for AnimationTimeline DOM methods when called from
  61   // script.
  62   Nullable<double> GetCurrentTimeAsDouble() const {
  63     return AnimationUtils::TimeDurationToDouble(GetCurrentTimeAsDuration(),
  64                                                 mRTPCallerType);
  65   }
  66
  67   TimeStamp GetCurrentTimeAsTimeStamp() const {
  68     Nullable<TimeDuration> currentTime = GetCurrentTimeAsDuration();
  69     return !currentTime.IsNull() ? ToTimeStamp(currentTime.Value())
  70                                  : TimeStamp();
  71   }
  72
  73   /**
  74    * Returns true if the times returned by GetCurrentTimeAsDuration() are
  75    * convertible to and from wallclock-based TimeStamp (e.g. from
  76    * TimeStamp::Now()) values using ToTimelineTime() and ToTimeStamp().
  77    *
  78    * Typically this is true, but it will be false in the case when this
  79    * timeline has no refresh driver or is tied to a refresh driver under test
  80    * control.
  81    */
  82   virtual bool TracksWallclockTime() const = 0;
  83
  84   /**
  85    * Converts a TimeStamp to the equivalent value in timeline time.
  86    * Note that when TracksWallclockTime() is false, there is no correspondence
  87    * between timeline time and wallclock time. In such a case, passing a
  88    * timestamp from TimeStamp::Now() to this method will not return a
  89    * meaningful result.
  90    */
  91   virtual Nullable<TimeDuration> ToTimelineTime(
  92       const TimeStamp& aTimeStamp) const = 0;
  93
  94   virtual TimeStamp ToTimeStamp(const TimeDuration& aTimelineTime) const = 0;
  95
  96   /**
  97    * Inform this timeline that |aAnimation| which is or was observing the
  98    * timeline, has been updated. This serves as both the means to associate
  99    * AND disassociate animations with a timeline. The timeline itself will
 100    * determine if it needs to begin, continue or stop tracking this animation.
 101    */
 102   virtual void NotifyAnimationUpdated(Animation& aAnimation);
 103
 104   /**
 105    * Returns true if any CSS animations, CSS transitions or Web animations are
 106    * currently associated with this timeline.  As soon as an animation is
 107    * applied to an element it is associated with the timeline even if it has a
 108    * delayed start, so this includes animations that may not be active for some
 109    * time.
 110    */
 111   bool HasAnimations() const { return !mAnimations.IsEmpty(); }
 112
 113   virtual void RemoveAnimation(Animation* aAnimation);
 114   virtual void NotifyAnimationContentVisibilityChanged(Animation* aAnimation,
 115                                                        bool aIsVisible);
 116
 117   virtual Document* GetDocument() const = 0;
 118
 119   virtual bool IsMonotonicallyIncreasing() const = 0;
 120
 121   RTPCallerType GetRTPCallerType() const { return mRTPCallerType; }
 122
 123   virtual bool IsScrollTimeline() const { return false; }
 124   virtual const ScrollTimeline* AsScrollTimeline() const { return nullptr; }
 125   virtual bool IsViewTimeline() const { return false; }
 126
 127   // For a monotonic timeline, there is no upper bound on current time, and
 128   // timeline duration is unresolved. For a non-monotonic (e.g. scroll)
 129   // timeline, the duration has a fixed upper bound.
 130   //
 131   // https://drafts.csswg.org/web-animations-2/#timeline-duration
 132   virtual Nullable<TimeDuration> TimelineDuration() const { return nullptr; }
 133
 134  protected:
 135   nsCOMPtr<nsIGlobalObject> mWindow;
 136
 137   // Animations observing this timeline
 138   //
 139   // We store them in (a) a hashset for quick lookup, and (b) a LinkedList to
 140   // maintain a fixed sampling order. Animations that are hidden by
 141   // `content-visibility` are not sampled and will only be in the hashset.
 142   // The LinkedList should always be a subset of the hashset.
 143   //
 144   // The hashset keeps a strong reference to each animation since
 145   // dealing with addref/release with LinkedList is difficult.
 146   using AnimationSet = nsTHashSet<nsRefPtrHashKey<dom::Animation>>;
 147   AnimationSet mAnimations;
 148   LinkedList<dom::Animation> mAnimationOrder;
 149
 150   // Whether the Timeline is System, ResistFingerprinting, or neither
 151   enum RTPCallerType mRTPCallerType;
 152 };
 153
 154 }  // namespace mozilla::dom
 155
 156 #endif  // mozilla_dom_AnimationTimeline_h