touch-event queue: Add a touch-event queue for all platforms.

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 10 matching lines @@
 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
 #include "content/browser/renderer_host/backing_store.h"
 #include "content/browser/renderer_host/backing_store_manager.h"
 #include "content/browser/renderer_host/gesture_event_filter.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_helper.h"
 #include "content/browser/renderer_host/render_widget_host_delegate.h"
 #include "content/browser/renderer_host/tap_suppression_controller.h"
+#include "content/browser/renderer_host/touch_event_queue.h"
 #include "content/common/accessibility_messages.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/view_messages.h"
 #include "content/port/browser/render_widget_host_view_port.h"
 #include "content/port/browser/smooth_scroll_gesture.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/common/compositor_util.h"
@@ skipping 101 matching lines @@
       ignore_input_events_(false),
       text_direction_updated_(false),
       text_direction_(WebKit::WebTextDirectionLeftToRight),
       text_direction_canceled_(false),
       suppress_next_char_events_(false),
       pending_mouse_lock_request_(false),
       allow_privileged_mouse_lock_(false),
       has_touch_handler_(false),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)),
       tick_active_smooth_scroll_gestures_task_posted_(false),
+      touch_event_queue_(new TouchEventQueue(this)),
       gesture_event_filter_(new GestureEventFilter(this)) {
   CHECK(delegate_);
   if (routing_id_ == MSG_ROUTING_NONE) {
     routing_id_ = process_->GetNextRoutingID();
     surface_id_ = GpuSurfaceTracker::Get()->AddSurfaceForRenderer(
         process_->GetID(),
         routing_id_);
   } else {
     // TODO(piman): This is a O(N) lookup, where we could forward the
     // information from the RenderWidgetHelper. The problem is that doing so
@@ skipping 771 matching lines @@
 void RenderWidgetHostImpl::ForwardGestureEvent(
     const WebKit::WebGestureEvent& gesture_event) {
   TRACE_EVENT0("renderer_host", "RenderWidgetHostImpl::ForwardGestureEvent");
   if (ignore_input_events_ || process_->IgnoreInputEvents() ||
       !gesture_event_filter_->ShouldForward(gesture_event))
     return;
 
   ForwardInputEvent(gesture_event, sizeof(WebGestureEvent), false);
 }
 
+void RenderWidgetHostImpl::ForwardTouchEventImmediately(
+    const WebKit::WebTouchEvent& touch_event) {
+  TRACE_EVENT0("renderer_host", "RenderWidgetHostImpl::ForwardTouchEvent");
+  if (ignore_input_events_ || process_->IgnoreInputEvents())
+    return;
+
+  ForwardInputEvent(touch_event, sizeof(WebKit::WebTouchEvent), false);
+}
+
 void RenderWidgetHostImpl::ForwardGestureEventImmediately(
     const WebKit::WebGestureEvent& gesture_event) {
   if (ignore_input_events_ || process_->IgnoreInputEvents())
     return;
   ForwardInputEvent(gesture_event, sizeof(WebGestureEvent), false);
 }
 
 void RenderWidgetHostImpl::ForwardKeyboardEvent(
     const NativeWebKeyboardEvent& key_event) {
   TRACE_EVENT0("renderer_host", "RenderWidgetHostImpl::ForwardKeyboardEvent");
@@ skipping 87 matching lines @@
   // after this line.
   next_mouse_move_.reset();
 
   increment_in_flight_event_count();
   StartHangMonitorTimeout(
       TimeDelta::FromMilliseconds(hung_renderer_delay_ms_));
 }
 
 void RenderWidgetHostImpl::ForwardTouchEvent(
     const WebKit::WebTouchEvent& touch_event) {
-  TRACE_EVENT0("renderer_host", "RenderWidgetHostImpl::ForwardTouchEvent");
-  if (ignore_input_events_ || process_->IgnoreInputEvents())
-    return;
-
-  // TODO(sad): Do touch-event coalescing when appropriate.
-  ForwardInputEvent(touch_event, sizeof(WebKit::WebTouchEvent), false);
+  touch_event_queue_->QueueEvent(touch_event);

[aelias_OOO_until_Jul13, 2012/10/16 23:28:38]

RenderWidgetHost is not doing anything here except bouncing the event to the
queue.  And the "Immediately" method above makes an API that consistent with the
other kinds of events.

I'm thinking touch-event senders should be changed to talk directly to the
queue.  Then you wouldn't need to change RWH::ForwardTouchEvent.  Maybe RWH can
have a public getter method returning a pointer to the queue?

[sadrul, 2012/10/16 23:49:14]

I actually considered doing something similar at first. But I thought it would
be better to keep the interaction between RWHV and RWH mostly unchanged, and
hide the queueing from the different RWHVs.

The ForwardTouchEvent/Immediately pair of functions are meant to be similar to
the ForwardGestureEvent/Immediately pair of functions, which do similar things
(throttles/coalesces events as appropriate), so I feel like this is more
consistent. In these cases, ForwardXXXEvent is the real API, and the Immediately
version is supposed to be used by the TouchEventQueue/GestureEventFilter as
appropriate, but since it is not possible to expose these 'Immediately'
functions without exposing all of the other privates in RWH, they became part of
the public API.

(Arguably, ForwardWheelEvent can also be split into two to be similar since it
also does throttling/coalescing).

 }
 
 #if defined(TOOLKIT_GTK)
 bool RenderWidgetHostImpl::KeyPressListenersHandleEvent(GdkEventKey* event) {
   if (event->type != GDK_KEY_PRESS)
     return false;
 
   for (std::list<KeyboardListener*>::iterator it = keyboard_listeners_.begin();
        it != keyboard_listeners_.end(); ++it) {
     if ((*it)->HandleKeyPressEvent(event))
@@ skipping 661 matching lines @@
 
   if (!processed && !is_hidden_ && view_)
     view_->UnhandledWheelEvent(current_wheel_event_);
 }
 
 void RenderWidgetHostImpl::ProcessGestureAck(bool processed, int type) {
   gesture_event_filter_->ProcessGestureAck(processed, type);
 }
 
 void RenderWidgetHostImpl::ProcessTouchAck(bool processed) {
-  if (view_)
-    view_->ProcessTouchAck(processed);
+  touch_event_queue_->ProcessTouchAck(processed);
 }
 
 void RenderWidgetHostImpl::OnMsgFocus() {
   // Only RenderViewHost can deal with that message.
   RecordAction(UserMetricsAction("BadMessageTerminate_RWH4"));
   GetProcess()->ReceivedBadMessage();
 }
 
 void RenderWidgetHostImpl::OnMsgBlur() {
   // Only RenderViewHost can deal with that message.
@@ skipping 376 matching lines @@
     return;
 
   OnRenderAutoResized(new_size);
 }
 
 void RenderWidgetHostImpl::DetachDelegate() {
   delegate_ = NULL;
 }
 
 }  // namespace content