1 files changed, 36 insertions, 0 deletions
diff --git a/gfx/layers/apz/util/TouchCounter.h b/gfx/layers/apz/util/TouchCounter.h
new file mode 100644
index 0000000000..c13f475355
--- /dev/null
+++ b/gfx/layers/apz/util/TouchCounter.h
@@ -0,0 +1,36 @@
+/* -*- 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_TouchCounter_h
+#define mozilla_layers_TouchCounter_h
+
+#include "mozilla/EventForwards.h"
+
+namespace mozilla {
+
+class MultiTouchInput;
+
+namespace layers {
+
+// TouchCounter simply tracks the number of active touch points. Feed it
+// your input events to update the internal state. Generally you should
+// only be calling one of the Update functions, depending on which type
+// of touch inputs you have access to.
+class TouchCounter {
+ public:
+  TouchCounter();
+  void Update(const MultiTouchInput& aInput);
+  void Update(const WidgetTouchEvent& aEvent);
+  uint32_t GetActiveTouchCount() const;
+
+ private:
+  uint32_t mActiveTouchCount;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif /* mozilla_layers_TouchCounter_h */