1 files changed, 71 insertions, 0 deletions
diff --git a/layout/style/AnimationCollection.h b/layout/style/AnimationCollection.h
new file mode 100644
index 0000000000..84f68506d1
--- /dev/null
+++ b/layout/style/AnimationCollection.h
@@ -0,0 +1,71 @@
+/* -*- 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_AnimationCollection_h
+#define mozilla_AnimationCollection_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/LinkedList.h"
+#include "mozilla/RefPtr.h"
+#include "nsCSSPseudoElements.h"
+#include "nsTArrayForwardDeclare.h"
+
+class nsAtom;
+class nsIFrame;
+class nsPresContext;
+
+namespace mozilla {
+namespace dom {
+class Element;
+}
+enum class PseudoStyleType : uint8_t;
+
+template <class AnimationType>
+class AnimationCollection
+    : public LinkedListElement<AnimationCollection<AnimationType>> {
+  typedef AnimationCollection<AnimationType> SelfType;
+
+ public:
+  AnimationCollection(dom::Element& aOwner, PseudoStyleType aPseudoType)
+      : mElement(aOwner), mPseudo(aPseudoType) {
+    MOZ_COUNT_CTOR(AnimationCollection);
+  }
+
+  ~AnimationCollection();
+
+  void Destroy();
+
+  // Given the frame |aFrame| with possibly animated content, finds its
+  // associated collection of animations. If |aFrame| is a generated content
+  // frame, this function may examine the parent frame to search for such
+  // animations.
+  static AnimationCollection* Get(const nsIFrame* aFrame);
+  static AnimationCollection* Get(const dom::Element* aElement,
+                                  PseudoStyleType aPseudoType);
+
+  // The element. Weak reference is fine since it owns us.
+  // FIXME(emilio): These are only needed for Destroy(), so maybe remove and
+  // rely on the caller clearing us properly?
+  dom::Element& mElement;
+  const PseudoStyleType mPseudo;
+
+  nsTArray<RefPtr<AnimationType>> mAnimations;
+
+ private:
+  // We distinguish between destroying this by calling Destroy() vs directly
+  // clearing the collection.
+  //
+  // The former case represents regular updating due to style changes and should
+  // trigger subsequent restyles.
+  //
+  // The latter case represents document tear-down or other DOM surgery in
+  // which case we should not trigger restyles.
+  bool mCalledDestroy = false;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_AnimationCollection_h