1 files changed, 71 insertions, 0 deletions
diff --git a/layout/style/nsTransitionManager.h b/layout/style/nsTransitionManager.h
new file mode 100644
index 0000000000..180bd6b8c2
--- /dev/null
+++ b/layout/style/nsTransitionManager.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/. */
+
+/* Code to start and animate CSS transitions. */
+
+#ifndef nsTransitionManager_h_
+#define nsTransitionManager_h_
+
+#include "mozilla/dom/CSSTransition.h"
+#include "AnimationCommon.h"
+#include "nsISupportsImpl.h"
+
+class nsPresContext;
+class nsCSSPropertyIDSet;
+
+namespace mozilla {
+class ComputedStyle;
+enum class PseudoStyleType : uint8_t;
+}  // namespace mozilla
+
+class nsTransitionManager final
+    : public mozilla::CommonAnimationManager<mozilla::dom::CSSTransition> {
+ public:
+  explicit nsTransitionManager(nsPresContext* aPresContext)
+      : mozilla::CommonAnimationManager<mozilla::dom::CSSTransition>(
+            aPresContext) {}
+
+  ~nsTransitionManager() final = default;
+
+  typedef mozilla::AnimationCollection<mozilla::dom::CSSTransition>
+      CSSTransitionCollection;
+
+  /**
+   * Update transitions for stylo.
+   */
+  bool UpdateTransitions(mozilla::dom::Element* aElement,
+                         mozilla::PseudoStyleType aPseudoType,
+                         const mozilla::ComputedStyle& aOldStyle,
+                         const mozilla::ComputedStyle& aNewStyle);
+
+ protected:
+  typedef nsTArray<RefPtr<mozilla::dom::CSSTransition>>
+      OwningCSSTransitionPtrArray;
+
+  // Update transitions. This will start new transitions,
+  // replace existing transitions, and stop existing transitions
+  // as needed. aDisp and aElement must be non-null.
+  // aElementTransitions is the collection of current transitions, and it
+  // could be a nullptr if we don't have any transitions.
+  bool DoUpdateTransitions(const nsStyleDisplay& aDisp,
+                           mozilla::dom::Element* aElement,
+                           mozilla::PseudoStyleType aPseudoType,
+                           CSSTransitionCollection*& aElementTransitions,
+                           const mozilla::ComputedStyle& aOldStyle,
+                           const mozilla::ComputedStyle& aNewStyle);
+
+  // Returns whether the transition actually started.
+  bool ConsiderInitiatingTransition(
+      nsCSSPropertyID aProperty, const nsStyleDisplay& aStyleDisplay,
+      uint32_t transitionIdx, mozilla::dom::Element* aElement,
+      mozilla::PseudoStyleType aPseudoType,
+      CSSTransitionCollection*& aElementTransitions,
+      const mozilla::ComputedStyle& aOldStyle,
+      const mozilla::ComputedStyle& aNewStyle,
+      nsCSSPropertyIDSet& aPropertiesChecked);
+};
+
+#endif /* !defined(nsTransitionManager_h_) */