1 files changed, 40 insertions, 0 deletions
diff --git a/gfx/layers/apz/util/ScrollingInteractionContext.h b/gfx/layers/apz/util/ScrollingInteractionContext.h
new file mode 100644
index 0000000000..cae953008b
--- /dev/null
+++ b/gfx/layers/apz/util/ScrollingInteractionContext.h
@@ -0,0 +1,40 @@
+/* -*- 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_layers_ScrollingInteractionContext_h
+#define mozilla_layers_ScrollingInteractionContext_h
+
+#include "mozilla/EventForwards.h"
+#include "mozilla/layers/ScrollableLayerGuid.h"
+
+namespace mozilla {
+namespace layers {
+
+// The ScrollingInteractionContext is used to store minor details of the
+// current scrolling interaction on the stack to avoid having to pass them
+// though the callstack
+class MOZ_STACK_CLASS ScrollingInteractionContext {
+ private:
+  static bool sScrollingToAnchor;
+
+ public:
+  // Functions to access downwards-propagated data
+  static bool IsScrollingToAnchor();
+
+  // Constructor sets the data to be propagated downwards
+  explicit ScrollingInteractionContext(bool aScrollingToAnchor);
+
+  // Destructor restores the previous state
+  ~ScrollingInteractionContext();
+
+ private:
+  bool mOldScrollingToAnchor;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif /* mozilla_layers_ScrollingInteractionContext_h */