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/dom/Document.h"
  12 #include "mozilla/TypedEnumBits.h"
  13 #include "nsCycleCollectionParticipant.h"
  14 #include "nsTHashtable.h"
  15
  16 class nsIFrame;
  17
  18 namespace mozilla {
  19
  20 namespace dom {
  21 class Document;
  22 }
  23
  24 class PendingAnimationTracker final {
  25  public:
  26   explicit PendingAnimationTracker(dom::Document* aDocument)
  27       : mDocument(aDocument) {}
  28
  29   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(PendingAnimationTracker)
  30   NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(PendingAnimationTracker)
  31
  32   void AddPlayPending(dom::Animation& aAnimation) {
  33     // We'd like to assert here that IsWaitingToPause(aAnimation) is false but
  34     // if |aAnimation| was tracked here as a pause-pending animation when it was
  35     // removed from |mDocument|, then re-attached to |mDocument|, and then
  36     // played again, we could end up here with IsWaitingToPause returning true.
  37     //
  38     // However, that should be harmless since all it means is that we'll call
  39     // Animation::TriggerOnNextTick or Animation::TriggerNow twice, both of
  40     // which will handle the redundant call gracefully.
  41     AddPending(aAnimation, mPlayPendingSet);
  42     mHasPlayPendingGeometricAnimations = CheckState::Indeterminate;
  43   }
  44   void RemovePlayPending(dom::Animation& aAnimation) {
  45     RemovePending(aAnimation, mPlayPendingSet);
  46     mHasPlayPendingGeometricAnimations = CheckState::Indeterminate;
  47   }
  48   bool IsWaitingToPlay(const dom::Animation& aAnimation) const {
  49     return IsWaiting(aAnimation, mPlayPendingSet);
  50   }
  51
  52   void AddPausePending(dom::Animation& aAnimation) {
  53     // As with AddPausePending, we'd like to assert that
  54     // IsWaitingToPlay(aAnimation) is false but there are some circumstances
  55     // where this can be true. Fortunately adding the animation to both pending
  56     // sets should be harmless.
  57     AddPending(aAnimation, mPausePendingSet);
  58   }
  59   void RemovePausePending(dom::Animation& aAnimation) {
  60     RemovePending(aAnimation, mPausePendingSet);
  61   }
  62   bool IsWaitingToPause(const dom::Animation& aAnimation) const {
  63     return IsWaiting(aAnimation, mPausePendingSet);
  64   }
  65
  66   void TriggerPendingAnimationsOnNextTick(const TimeStamp& aReadyTime);
  67   void TriggerPendingAnimationsNow();
  68   bool HasPendingAnimations() const {
  69     return mPlayPendingSet.Count() > 0 || mPausePendingSet.Count() > 0;
  70   }
  71
  72   /**
  73    * Looks amongst the set of play-pending animations, and, if there are
  74    * animations that affect geometric properties, notifies all play-pending
  75    * animations so that they can be synchronized, if needed.
  76    */
  77   void MarkAnimationsThatMightNeedSynchronization();
  78
  79  private:
  80   ~PendingAnimationTracker() = default;
  81
  82   void EnsurePaintIsScheduled();
  83
  84   typedef nsTHashtable<nsRefPtrHashKey<dom::Animation>> AnimationSet;
  85
  86   void AddPending(dom::Animation& aAnimation, AnimationSet& aSet);
  87   void RemovePending(dom::Animation& aAnimation, AnimationSet& aSet);
  88   bool IsWaiting(const dom::Animation& aAnimation,
  89                  const AnimationSet& aSet) const;
  90
  91   AnimationSet mPlayPendingSet;
  92   AnimationSet mPausePendingSet;
  93   RefPtr<dom::Document> mDocument;
  94
  95  public:
  96   enum class CheckState {
  97     Indeterminate = 0,
  98     Absent = 1 << 0,
  99     AnimationsPresent = 1 << 1,
 100     TransitionsPresent = 1 << 2,
 101   };
 102
 103  private:
 104   CheckState mHasPlayPendingGeometricAnimations = CheckState::Indeterminate;
 105 };
 106
 107 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(PendingAnimationTracker::CheckState)
 108
 109 }  // namespace mozilla
 110
 111 #endif  // mozilla_dom_PendingAnimationTracker_h