dom/animation/PendingAnimationTracker.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_PendingAnimationTracker_h
   8 #define mozilla_dom_PendingAnimationTracker_h
   9
  10 #include "mozilla/dom/Animation.h"
  11 #include "mozilla/TypedEnumBits.h"
  12 #include "nsCycleCollectionParticipant.h"
  13 #include "nsTHashSet.h"
  14
  15 class nsIFrame;
  16
  17 namespace mozilla {
  18
  19 namespace dom {
  20 class Document;
  21 }
  22
  23 class PendingAnimationTracker final {
  24  public:
  25   explicit PendingAnimationTracker(dom::Document* aDocument);
  26
  27   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(PendingAnimationTracker)
  28   NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(PendingAnimationTracker)
  29
  30   void AddPlayPending(dom::Animation& aAnimation) {
  31     // We'd like to assert here that IsWaitingToPause(aAnimation) is false but
  32     // if |aAnimation| was tracked here as a pause-pending animation when it was
  33     // removed from |mDocument|, then re-attached to |mDocument|, and then
  34     // played again, we could end up here with IsWaitingToPause returning true.
  35     //
  36     // However, that should be harmless since all it means is that we'll call
  37     // Animation::TriggerOnNextTick or Animation::TriggerNow twice, both of
  38     // which will handle the redundant call gracefully.
  39     AddPending(aAnimation, mPlayPendingSet);
  40     mHasPlayPendingGeometricAnimations = CheckState::Indeterminate;
  41   }
  42   void RemovePlayPending(dom::Animation& aAnimation) {
  43     RemovePending(aAnimation, mPlayPendingSet);
  44     mHasPlayPendingGeometricAnimations = CheckState::Indeterminate;
  45   }
  46   bool IsWaitingToPlay(const dom::Animation& aAnimation) const {
  47     return IsWaiting(aAnimation, mPlayPendingSet);
  48   }
  49
  50   void AddPausePending(dom::Animation& aAnimation) {
  51     // As with AddPausePending, we'd like to assert that
  52     // IsWaitingToPlay(aAnimation) is false but there are some circumstances
  53     // where this can be true. Fortunately adding the animation to both pending
  54     // sets should be harmless.
  55     AddPending(aAnimation, mPausePendingSet);
  56   }
  57   void RemovePausePending(dom::Animation& aAnimation) {
  58     RemovePending(aAnimation, mPausePendingSet);
  59   }
  60   bool IsWaitingToPause(const dom::Animation& aAnimation) const {
  61     return IsWaiting(aAnimation, mPausePendingSet);
  62   }
  63
  64   void TriggerPendingAnimationsOnNextTick(const TimeStamp& aReadyTime);
  65   void TriggerPendingAnimationsNow();
  66   bool HasPendingAnimations() const {
  67     return mPlayPendingSet.Count() > 0 || mPausePendingSet.Count() > 0;
  68   }
  69
  70   /**
  71    * Looks amongst the set of play-pending animations, and, if there are
  72    * animations that affect geometric properties, notifies all play-pending
  73    * animations so that they can be synchronized, if needed.
  74    */
  75   void MarkAnimationsThatMightNeedSynchronization();
  76
  77  private:
  78   ~PendingAnimationTracker() = default;
  79
  80   void EnsurePaintIsScheduled();
  81
  82   using AnimationSet = nsTHashSet<nsRefPtrHashKey<dom::Animation>>;
  83
  84   void AddPending(dom::Animation& aAnimation, AnimationSet& aSet);
  85   void RemovePending(dom::Animation& aAnimation, AnimationSet& aSet);
  86   bool IsWaiting(const dom::Animation& aAnimation,
  87                  const AnimationSet& aSet) const;
  88
  89   AnimationSet mPlayPendingSet;
  90   AnimationSet mPausePendingSet;
  91   RefPtr<dom::Document> mDocument;
  92
  93  public:
  94   enum class CheckState {
  95     Indeterminate = 0,
  96     Absent = 1 << 0,
  97     AnimationsPresent = 1 << 1,
  98     TransitionsPresent = 1 << 2,
  99   };
 100
 101  private:
 102   CheckState mHasPlayPendingGeometricAnimations = CheckState::Indeterminate;
 103 };
 104
 105 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(PendingAnimationTracker::CheckState)
 106
 107 }  // namespace mozilla
 108
 109 #endif  // mozilla_dom_PendingAnimationTracker_h