Move TouchEvent timeout code to the TouchEventQueue

content/browser/renderer_host/input/touch_event_queue.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EVENT_QUEUE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EVENT_QUEUE_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 20 matching lines @@
       const TouchEventWithLatencyInfo& event,
       InputEventAckState ack_result) = 0;
 };
 
 // A queue for throttling and coalescing touch-events.
 class CONTENT_EXPORT TouchEventQueue {
  public:
 
   // The |client| must outlive the TouchEventQueue.
   explicit TouchEventQueue(TouchEventQueueClient* client);
-  virtual ~TouchEventQueue();
+  ~TouchEventQueue();
 
   // Adds an event to the queue. The event may be coalesced with previously
   // queued events (e.g. consecutive touch-move events can be coalesced into a
   // single touch-move event). The event may also be immediately forwarded to
   // the renderer (e.g. when there are no other queued touch event).
   void QueueEvent(const TouchEventWithLatencyInfo& event);
 
   // Notifies the queue that a touch-event has been processed by the renderer.
   // At this point, the queue may send one or more gesture events and/or
   // additional queued touch-events to the renderer.
   void ProcessTouchAck(InputEventAckState ack_result,
                        const ui::LatencyInfo& latency_info);
 
   // When GestureScrollBegin is received, we send a touch cancel to renderer,
   // route all the following touch events directly to client, and ignore the
-  // ack for the touch cancel. When GestureScrollEnd/GestureFlingStart is
-  // received, we resume the normal flow of sending touch events to renderer.
+  // ack for the touch cancel. When Gesture{ScrollEnd,FlingStart} is received,
+  // resume the normal flow of sending touch events to the renderer.
   void OnGestureScrollEvent(const GestureEventWithLatencyInfo& gesture_event);
 
   // Empties the queue of touch events. This may result in any number of gesture
   // events being sent to the renderer.
   void FlushQueue();
 
   // Returns whether the currently pending touch event (waiting ACK) is for
   // a touch start event.
   bool IsPendingAckTouchStart() const;
 
-  // Returns whether the event-queue is empty.
+  // Sets whether a delayed touch ack will cancel and flush the current
+  // touch sequence.
+  void SetAckTimeoutEnabled(bool enabled, size_t ack_timeout_delay_ms);
+
   bool empty() const WARN_UNUSED_RESULT {
     return touch_queue_.empty();
   }
 
-  bool no_touch_to_renderer() const {
-    return no_touch_to_renderer_;
+  size_t size() const {
+    return touch_queue_.size();
+  }
+
+  bool ack_timeout_enabled() const {
+    return ack_timeout_enabled_;
   }
 
  private:
+  class TouchTimeoutHandler;
+  friend class TouchTimeoutHandler;
   friend class TouchEventQueueTest;
 
-  size_t GetQueueSize() const;
-  const TouchEventWithLatencyInfo& GetLatestEvent() const;
+  bool HasTimeoutEvent() const;
+  bool IsTimeoutRunningForTesting() const;
+  const TouchEventWithLatencyInfo& GetLatestEventForTesting() const;
 
   // Walks the queue, checking each event for |ShouldForwardToRenderer()|.
   // If true, forwards the touch event and stops processing further events.
   // If false, acks the event with |INPUT_EVENT_ACK_STATE_NO_CONSUMER_EXISTS|.
   void TryForwardNextEventToRenderer();
 
   // Pops the touch-event from the top of the queue and sends it to the
   // TouchEventQueueClient. This reduces the size of the queue by one.
   void PopTouchEventToClient(InputEventAckState ack_result,
                              const ui::LatencyInfo& renderer_latency_info);
 
   bool ShouldForwardToRenderer(const blink::WebTouchEvent& event) const;
+  void ForwardToRenderer(const TouchEventWithLatencyInfo& event);
+  void UpdateTouchAckStates(const blink::WebTouchEvent& event,
+                            InputEventAckState ack_result);
+
 
   // Handles touch event forwarding and ack'ed event dispatch.
   TouchEventQueueClient* client_;
 
   typedef std::deque<CoalescedWebTouchEvent*> TouchQueue;
   TouchQueue touch_queue_;
 
   // Maintain the ACK status for each touch point.
   typedef std::map<int, InputEventAckState> TouchPointAckStates;
   TouchPointAckStates touch_ack_states_;
 
   // Used to defer touch forwarding when ack dispatch triggers |QueueEvent()|.
   // If not NULL, |dispatching_touch_ack_| is the touch event of which the ack
   // is being dispatched.
   CoalescedWebTouchEvent* dispatching_touch_ack_;
 
-  // Don't send touch events to renderer. This is enabled when the page
-  // is scrolling. This behaviour is currently enabled only on aura behind
-  // a flag.
+  // Used to prevent touch timeout scheduling if we receive a synchronous
+  // ack after forwarding a touch event to the client.
+  bool dispatching_touch_;
+
+  // Don't send touch events to the renderer while scrolling.
   bool no_touch_to_renderer_;
 
+  // Whether an event in the current (multi)touch sequence was consumed by the
+  // renderer.  The touch timeout will never be activated when this is true.
+  bool renderer_is_consuming_touch_gesture_;
+
+  // Optional handler for timed-out touch event acks, disabled by default.
+  bool ack_timeout_enabled_;
+  scoped_ptr<TouchTimeoutHandler> timeout_handler_;
+
   DISALLOW_COPY_AND_ASSIGN(TouchEventQueue);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EVENT_QUEUE_H_