Support vsync-aligned wheel event dispatch

content/browser/renderer_host/input/input_router_impl.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_INPUT_ROUTER_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_
 
 #include <queue>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/memory/scoped_vector.h"
 #include "base/time/time.h"
 #include "content/browser/renderer_host/input/gesture_event_queue.h"
 #include "content/browser/renderer_host/input/input_router.h"
 #include "content/browser/renderer_host/input/touch_action_filter.h"
 #include "content/browser/renderer_host/input/touch_event_queue.h"
 #include "content/browser/renderer_host/input/touchpad_tap_suppression_controller.h"
+#include "content/browser/renderer_host/input/wheel_event_queue.h"
 #include "content/common/input/input_event_stream_validator.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 
 namespace IPC {
 class Sender;
 }
 
 namespace ui {
 class LatencyInfo;
 }
 
 namespace content {
 
 class InputAckHandler;
 class InputRouterClient;
 class OverscrollController;
 struct DidOverscrollParams;
 struct InputEventAck;
 
 // A default implementation for browser input event routing.
 class CONTENT_EXPORT InputRouterImpl
     : public NON_EXPORTED_BASE(InputRouter),
       public NON_EXPORTED_BASE(GestureEventQueueClient),
       public NON_EXPORTED_BASE(TouchEventQueueClient),
-      public NON_EXPORTED_BASE(TouchpadTapSuppressionControllerClient) {
+      public NON_EXPORTED_BASE(TouchpadTapSuppressionControllerClient),
+      public NON_EXPORTED_BASE(WheelEventQueueClient) {
  public:
   struct CONTENT_EXPORT Config {
     Config();
     GestureEventQueue::Config gesture_config;
     TouchEventQueue::Config touch_config;
+    bool buffer_wheel_events_until_flush;
   };
 
   InputRouterImpl(IPC::Sender* sender,
                   InputRouterClient* client,
                   InputAckHandler* ack_handler,
                   int routing_id,
                   const Config& config);
   ~InputRouterImpl() override;
 
   // InputRouter
@@ skipping 20 matching lines @@
   // TouchpadTapSuppressionControllerClient
   void SendMouseEventImmediately(
       const MouseEventWithLatencyInfo& mouse_event) override;
 
   // TouchEventQueueClient
   void SendTouchEventImmediately(
       const TouchEventWithLatencyInfo& touch_event) override;
   void OnTouchEventAck(const TouchEventWithLatencyInfo& event,
                        InputEventAckState ack_result) override;
 
-  // GetureEventFilterClient
+  // GestureEventQueueClient
   void SendGestureEventImmediately(
       const GestureEventWithLatencyInfo& gesture_event) override;
   void OnGestureEventAck(const GestureEventWithLatencyInfo& event,
                          InputEventAckState ack_result) override;
 
+  // WheelEventQueueClient
+  void SendWheelEventImmediately(
+      const MouseWheelEventWithLatencyInfo& wheel_event) override;
+  void OnWheelEventAck(const MouseWheelEventWithLatencyInfo& event,
+                       InputEventAckState ack_result) override;
+  void SetNeedsFlush() override;
+
+  bool SendSelectMessage(scoped_ptr<IPC::Message> message);
   bool SendMoveCaret(scoped_ptr<IPC::Message> message);
-  bool SendSelectMessage(scoped_ptr<IPC::Message> message);
   bool Send(IPC::Message* message);
 
   // Filters and forwards |input_event| to the appropriate handler.
   void FilterAndSendWebInputEvent(const blink::WebInputEvent& input_event,
                                   const ui::LatencyInfo& latency_info);
 
   // Utility routine for filtering and forwarding |input_event| to the
   // appropriate handler. |input_event| will be offered to the overscroll
   // controller, client and renderer, in that order.
   void OfferToHandlers(const blink::WebInputEvent& input_event,
@@ skipping 95 matching lines @@
 
   // True if a mouse move event was sent to the render view and we are waiting
   // for a corresponding InputHostMsg_HandleInputEvent_ACK message.
   bool mouse_move_pending_;
 
   // The next mouse move event to send (only non-null while mouse_move_pending_
   // is true).
   scoped_ptr<MouseEventWithLatencyInfo> next_mouse_move_;
   MouseEventWithLatencyInfo current_mouse_move_;
 
-  // (Similar to |mouse_move_pending_|.) True if a mouse wheel event was sent
-  // and we are waiting for a corresponding ack.
-  bool mouse_wheel_pending_;
-  MouseWheelEventWithLatencyInfo current_wheel_event_;
-
-  // (Similar to |next_mouse_move_|.) The next mouse wheel events to send.
-  // Unlike mouse moves, mouse wheel events received while one is pending are
-  // coalesced (by accumulating deltas) if they match the previous event in
-  // modifiers. On the Mac, in particular, mouse wheel events are received at a
-  // high rate; not waiting for the ack results in jankiness, and using the same
-  // mechanism as for mouse moves (just dropping old events when multiple ones
-  // would be queued) results in very slow scrolling.
-  typedef std::deque<MouseWheelEventWithLatencyInfo> WheelEventQueue;
-  WheelEventQueue coalesced_mouse_wheel_events_;
-
   // A queue of keyboard events. We can't trust data from the renderer so we
   // stuff key events into a queue and pop them out on ACK, feeding our copy
   // back to whatever unhandled handler instead of the returned version.
   typedef std::deque<NativeWebKeyboardEventWithLatencyInfo> KeyQueue;
   KeyQueue key_queue_;
 
   // The time when an input event was sent to the client.
   base::TimeTicks input_event_start_time_;
 
   // The source of the ack within the scope of |ProcessInputEventAck()|.
   // Defaults to ACK_SOURCE_NONE.
   AckSource current_ack_source_;
 
   // Whether a |FlushInput()| call has yet been accompanied by a
   // |DidFlushAllInput()| call to the client.
   bool flush_requested_;
 
   // Whether there are any active flings in the renderer. As the fling
   // end notification is asynchronous, we use a count rather than a boolean
   // to avoid races in bookkeeping when starting a new fling.
   int active_renderer_fling_count_;
 
   TouchEventQueue touch_event_queue_;
   GestureEventQueue gesture_event_queue_;
+  WheelEventQueue wheel_event_queue_;
   TouchActionFilter touch_action_filter_;
   InputEventStreamValidator input_stream_validator_;
   InputEventStreamValidator output_stream_validator_;
 
   DISALLOW_COPY_AND_ASSIGN(InputRouterImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_IMPL_H_