Suppress touchscreen tap immediately after a GestureFlingCancel

content/browser/renderer_host/gesture_event_filter.h

Index: content/browser/renderer_host/gesture_event_filter.h
diff --git a/content/browser/renderer_host/gesture_event_filter.h b/content/browser/renderer_host/gesture_event_filter.h
index 229904ea8d705d904cd3ca93947610ef25fa694f..b7b7d1c00871a179cc6f46329c58f2f143e6dfe8 100644
--- a/content/browser/renderer_host/gesture_event_filter.h
+++ b/content/browser/renderer_host/gesture_event_filter.h
@@ -15,7 +15,8 @@
 namespace content {
 class MockRenderWidgetHost;
 class RenderWidgetHostImpl;
-class TapSuppressionController;
+class TouchpadTapSuppressionController;
+class TouchscreenTapSuppressionController;
 
 // Applies a sequence of filters to WebGestureEvents instances.
 // First: the sequence is filtered for bounces. A bounce is when the finger
@@ -49,8 +50,8 @@ class GestureEventFilter {
   // definitely not in progress.
   void FlingHasBeenHalted();
 
-  // Return the |TapSuppressionController| instance.
-  TapSuppressionController* GetTapSuppressionController();
+  // Return the |TouchpadTapSuppressionController| instance.
+  TouchpadTapSuppressionController* GetTouchpadTapSuppressionController();
 
   // Returns whether there are any gesture event in the queue.
   bool HasQueuedGestureEvents() const;
@@ -58,6 +59,14 @@ class GestureEventFilter {
   // Returns the last gesture event that was sent to the renderer.
   const WebKit::WebInputEvent& GetGestureEventAwaitingAck() const;
 

[mohsen, 2013/02/04 15:09:05]

Following two public methods are added to be called from
TouchscreenTapSuppressionController.

+  // Tries forwarding the event to the tap deferral sub-filter.
+  void ForwardGestureEventForDeferral(
+      const WebKit::WebGestureEvent& gesture_event);
+
+  // Tries forwarding the event, skipping the tap deferral sub-filter.
+  void ForwardGestureEventSkipDeferral(
+      const WebKit::WebGestureEvent& gesture_event);
+
  private:
   friend class MockRenderWidgetHost;
 
@@ -86,11 +95,23 @@ class GestureEventFilter {
   bool ShouldForwardForBounceReduction(
       const WebKit::WebGestureEvent& gesture_event);
 
+  // Sub-filter for removing extra GestureFlingCancels.
+  bool ShouldForwardForGFCFiltering(
+      const WebKit::WebGestureEvent& gesture_event);
+
+  // Sub-filter for suppressing taps immediately after a GestureFlingCancel.
+  bool ShouldForwardForTapSuppression(
+      const WebKit::WebGestureEvent& gesture_event);
+
   // Sub-filter for removing unnecessary GestureFlingCancels and deferring
   // GestureTapDowns.
   bool ShouldForwardForTapDeferral(
       const WebKit::WebGestureEvent& gesture_event);
 
+  // Enqueus the event in the coalesced events queue and if it is in front of

[rjkroege, 2013/02/05 16:00:07]

nit sp Enqueues

[mohsen, 2013/02/06 16:13:06]

Done.

+  // the queue, forwards it immediately.
+  void TryForwardGestureEvent(const WebKit::WebGestureEvent& gesture_event);
+
   // Only a RenderWidgetHostViewImpl can own an instance.
   RenderWidgetHostImpl* render_widget_host_;
 
@@ -107,7 +128,18 @@ class GestureEventFilter {
   // An object tracking the state of touchpad action on the delivery of mouse
   // events to the renderer to filter mouse  immediately after a touchpad
   // fling canceling tap.
-  scoped_ptr<TapSuppressionController> tap_suppression_controller_;
+  scoped_ptr<TouchpadTapSuppressionController>
+      touchpad_tap_suppression_controller_;

[mohsen, 2013/02/04 15:09:05]

Should this line be broken like this?

[rjkroege, 2013/02/05 16:00:07]

general algorithm is if len(line) > 80, split at space and indent 4 spaces. So
this looks good to me.

+
+  // An object tracking the state of touchscreen action on the delivery of

[rjkroege, 2013/02/05 16:00:07]

of a touchscreen

[mohsen, 2013/02/06 16:13:06]

Sentence changed a bit.

+  // gesture tap events to the renderer to filter taps immediately after a
+  // touchscreen fling canceling tap.
+  scoped_ptr<TouchscreenTapSuppressionController>
+      touchscreen_tap_suppression_controller_;
+
+  // Whenever a GestureFlingCancel is forwarded, its source device is saved, so

[rjkroege, 2013/02/05 16:00:07]

Do we still queue the events until acked? If so, we have this state in the GFC
in the queue. Could this piece of info be stored there? 

My preference (not for you to implement in this CL) would be to add more state
to the ACK.

[mohsen, 2013/02/06 16:13:06]

Yes, you are right. The event is in front of queue, waiting for the ACK. I
removed this field and used the event in front of queue, instead.

+  // that when an Ack for a GFC is received, we know its source device.
+  WebKit::WebGestureEvent::SourceDevice last_gfc_source_device_;
 
   typedef std::deque<WebKit::WebGestureEvent> GestureEventQueue;