Bug 1197620 - Part 1 - Stop all animations in destroyed frames. r=bbirtles

layout/base/RestyleManager.cpp

@@ -90,6 +90,7 @@ RestyleManager::RestyleManager(nsPresContext* aPresContext)
                                         MostRecentRefresh())
   , mAnimationGeneration(0)
   , mReframingStyleContexts(nullptr)
+  , mAnimationsWithDestroyedFrame(nullptr)
   , mPendingRestyles(ELEMENT_HAS_PENDING_RESTYLE |
                      ELEMENT_IS_POTENTIAL_RESTYLE_ROOT |
                      ELEMENT_IS_CONDITIONAL_RESTYLE_ANCESTOR)
@@ -1081,6 +1082,44 @@ RestyleManager::ReframingStyleContexts::~ReframingStyleContexts()
   mRestyleManager->mPresContext->FrameConstructor()->CreateNeededFrames();
 }
 
+RestyleManager::AnimationsWithDestroyedFrame::AnimationsWithDestroyedFrame(
+                                          RestyleManager* aRestyleManager)
+  : mRestyleManager(aRestyleManager)
+  , mRestorePointer(mRestyleManager->mAnimationsWithDestroyedFrame)
+{
+  MOZ_ASSERT(!mRestyleManager->mAnimationsWithDestroyedFrame,
+             "shouldn't construct recursively");
+  mRestyleManager->mAnimationsWithDestroyedFrame = this;
+}
+
+void
+RestyleManager::AnimationsWithDestroyedFrame::StopAnimationsForElementsWithoutFrames()
+{
+  StopAnimationsWithoutFrame(mContents,
+    nsCSSPseudoElements::ePseudo_NotPseudoElement);
+  StopAnimationsWithoutFrame(mBeforeContents,
+    nsCSSPseudoElements::ePseudo_before);
+  StopAnimationsWithoutFrame(mAfterContents,
+    nsCSSPseudoElements::ePseudo_after);
+}
+
+void
+RestyleManager::AnimationsWithDestroyedFrame::StopAnimationsWithoutFrame(
+  nsTArray<nsRefPtr<nsIContent>>& aArray,
+  nsCSSPseudoElements::Type aPseudoType)
+{
+  nsAnimationManager* animationManager =
+    mRestyleManager->PresContext()->AnimationManager();
+  for (nsIContent* content : aArray) {
+    if (content->GetPrimaryFrame()) {
+      continue;
+    }
+    dom::Element* element = content->AsElement();
+
+    animationManager->StopAnimationsForElement(element, aPseudoType);
+  }
+}
+
 static inline dom::Element*
 ElementForStyleContext(nsIContent* aParentContent,
                        nsIFrame* aFrame,
@@ -1780,6 +1819,10 @@ RestyleManager::EndProcessingRestyles()
 {
   FlushOverflowChangedTracker();
 
+  MOZ_ASSERT(mAnimationsWithDestroyedFrame);
+  mAnimationsWithDestroyedFrame->
+    StopAnimationsForElementsWithoutFrames();
+
   // Set mInStyleRefresh to false now, since the EndUpdate call might
   // add more restyles.
   mInStyleRefresh = false;

layout/base/RestyleManager.h

@@ -49,6 +49,8 @@ private:
   {
     MOZ_ASSERT(!mReframingStyleContexts,
                "temporary member should be nulled out before destruction");
+    MOZ_ASSERT(!mAnimationsWithDestroyedFrame,
+               "leaving dangling pointers from AnimationsWithDestroyedFrame");
   }
 
 public:
@@ -247,6 +249,65 @@ public:
                         nsStyleContext* aOldStyleContext,
                         nsRefPtr<nsStyleContext>* aNewStyleContext /* inout */);
 
+  // AnimationsWithDestroyedFrame is used to stop animations on elements that
+  // have no frame at the end of the restyling process.
+  // It only lives during the restyling process.
+  class MOZ_STACK_CLASS AnimationsWithDestroyedFrame final {
+  public:
+    // Construct a AnimationsWithDestroyedFrame object.  The caller must
+    // ensure that aRestyleManager lives at least as long as the
+    // object.  (This is generally easy since the caller is typically a
+    // method of RestyleManager.)
+    explicit AnimationsWithDestroyedFrame(RestyleManager* aRestyleManager);
+    ~AnimationsWithDestroyedFrame()
+    {
+    }
+
+    // This method takes the content node for the generated content for
+    // animation on ::before and ::after, rather than the content node for
+    // the real element.
+    void Put(nsIContent* aContent, nsStyleContext* aStyleContext) {
+      MOZ_ASSERT(aContent);
+      nsCSSPseudoElements::Type pseudoType = aStyleContext->GetPseudoType();
+      if (pseudoType == nsCSSPseudoElements::ePseudo_NotPseudoElement) {
+        mContents.AppendElement(aContent);
+      } else if (pseudoType == nsCSSPseudoElements::ePseudo_before) {
+        MOZ_ASSERT(aContent->NodeInfo()->NameAtom() == nsGkAtoms::mozgeneratedcontentbefore);
+        mBeforeContents.AppendElement(aContent->GetParent());
+      } else if (pseudoType == nsCSSPseudoElements::ePseudo_after) {
+        MOZ_ASSERT(aContent->NodeInfo()->NameAtom() == nsGkAtoms::mozgeneratedcontentafter);
+        mAfterContents.AppendElement(aContent->GetParent());
+      }
+    }
+
+    void StopAnimationsForElementsWithoutFrames();
+
+  private:
+    void StopAnimationsWithoutFrame(nsTArray<nsRefPtr<nsIContent>>& aArray,
+                                    nsCSSPseudoElements::Type aPseudoType);
+
+    RestyleManager* mRestyleManager;
+    AutoRestore<AnimationsWithDestroyedFrame*> mRestorePointer;
+
+    // Below three arrays might include elements that have already had their
+    // animations stopped.
+    //
+    // mBeforeContents and mAfterContents hold the real element rather than
+    // the content node for the generated content (which might change during
+    // a reframe)
+    nsTArray<nsRefPtr<nsIContent>> mContents;
+    nsTArray<nsRefPtr<nsIContent>> mBeforeContents;
+    nsTArray<nsRefPtr<nsIContent>> mAfterContents;
+  };
+
+  /**
+   * Return the current AnimationsWithDestroyedFrame struct, or null if we're
+   * not currently in a restyling operation.
+   */
+  AnimationsWithDestroyedFrame* GetAnimationsWithDestroyedFrame() {
+    return mAnimationsWithDestroyedFrame;
+  }
+
 private:
   void RestyleForEmptyChange(Element* aContainer);
 
@@ -491,6 +552,7 @@ private:
   uint64_t mAnimationGeneration;
 
   ReframingStyleContexts* mReframingStyleContexts;
+  AnimationsWithDestroyedFrame* mAnimationsWithDestroyedFrame;
 
   RestyleTracker mPendingRestyles;
 

layout/base/RestyleTracker.cpp

@@ -225,6 +225,12 @@ RestyleTracker::DoProcessRestyles()
     docShell->GetRecordProfileTimelineMarkers(&isTimelineRecording);
   }
 
+  // Create a AnimationsWithDestroyedFrame during restyling process to
+  // stop animations on elements that have no frame at the end of the
+  // restyling process.
+  RestyleManager::AnimationsWithDestroyedFrame
+    animationsWithDestroyedFrame(mRestyleManager);
+
   // Create a ReframingStyleContexts struct on the stack and put it in our
   // mReframingStyleContexts for almost all of the remaining scope of
   // this function.

layout/generic/nsFrame.cpp

@@ -687,6 +687,17 @@ nsFrame::DestroyFrom(nsIFrame* aDestructRoot)
     }
   }
 
+  if (nsLayoutUtils::HasCurrentAnimations(static_cast<nsIFrame*>(this))) {
+    // If no new frame for this element is created by the end of the
+    // restyling process, stop animations for this frame
+    RestyleManager::AnimationsWithDestroyedFrame* adf =
+      presContext->RestyleManager()->GetAnimationsWithDestroyedFrame();
+    // AnimationsWithDestroyedFrame only lives during the restyling process.
+    if (adf) {
+      adf->Put(mContent, mStyleContext);
+    }
+  }
+
   shell->NotifyDestroyingFrame(this);
 
   if (mState & NS_FRAME_EXTERNAL_REFERENCE) {

layout/style/nsAnimationManager.cpp

@@ -551,6 +551,22 @@ nsAnimationManager::CheckAnimationRule(nsStyleContext* aStyleContext,
   return GetAnimationRule(aElement, aStyleContext->GetPseudoType());
 }
 
+void
+nsAnimationManager::StopAnimationsForElement(
+  mozilla::dom::Element* aElement,
+  nsCSSPseudoElements::Type aPseudoType)
+{
+  MOZ_ASSERT(aElement);
+  AnimationCollection* collection =
+    GetAnimations(aElement, aPseudoType, false);
+  if (!collection) {
+    return;
+  }
+
+  nsAutoAnimationMutationBatch mb(aElement->OwnerDoc());
+  collection->Destroy();
+}
+
 struct KeyframeData {
   float mKey;
   uint32_t mIndex; // store original order since sort algorithm is not stable

layout/style/nsAnimationManager.h

@@ -290,6 +290,12 @@ public:
   void DispatchEvents()  { mEventDispatcher.DispatchEvents(mPresContext); }
   void ClearEventQueue() { mEventDispatcher.ClearEventQueue(); }
 
+  // Stop animations on the element. This method takes the real element
+  // rather than the element for the generated content for animations on
+  // ::before and ::after.
+  void StopAnimationsForElement(mozilla::dom::Element* aElement,
+                                nsCSSPseudoElements::Type aPseudoType);
+
 protected:
   virtual ~nsAnimationManager() {}