Prepare SyntheticPointerAction to handle touch actions for multiple fingers

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 <set>
 #include <utility>
@@ skipping 1148 matching lines @@
   if (!synthetic_gesture_controller_ && view_) {
     synthetic_gesture_controller_.reset(
         new SyntheticGestureController(view_->CreateSyntheticGestureTarget()));
   }
   if (synthetic_gesture_controller_) {
     synthetic_gesture_controller_->QueueSyntheticGesture(
         std::move(synthetic_gesture), on_complete);
   }
 }
 
+void RenderWidgetHostImpl::QueueSyntheticPointerAction(
+    const SyntheticPointerActionParams& gesture_params,
+    const base::Callback<void(SyntheticGesture::Result)>& on_complete) {
+  if (!synthetic_gesture_controller_ && view_) {
+    synthetic_gesture_controller_.reset(
+        new SyntheticGestureController(view_->CreateSyntheticGestureTarget()));
+  }
+  if (synthetic_gesture_controller_) {

[tdresser, 2016/05/31 13:44:26]

Should this ever run if !view_?

It might be easier to write as:

if (!view_)
  return;

if (!synthetic_gesture_controller_)
  sgc.reset(...);

sgc->Queue...

[lanwei, 2016/06/02 13:26:27]

I feel if the synthetic_gesture_controller is not null, but view is null then
if (!view_)
   return; 
will be skip synthetic_gesture_controller_->QueueSyntheticPointerAction.

[tdresser, 2016/06/02 13:39:24]

Is there ever a case where the controller is non-null but the view is null?

+    synthetic_gesture_controller_->QueueSyntheticPointerAction(gesture_params,
+                                                               on_complete);
+  }
+}
+
 void RenderWidgetHostImpl::SetCursor(const WebCursor& cursor) {
   if (!view_)
     return;
   view_->UpdateCursor(cursor);
 }
 
 void RenderWidgetHostImpl::ShowContextMenuAtPoint(const gfx::Point& point) {
   Send(new ViewMsg_ShowContextMenu(
       GetRoutingID(), ui::MENU_SOURCE_MOUSE, point));
 }
@@ skipping 503 matching lines @@
 void RenderWidgetHostImpl::OnQueueSyntheticGesture(
     const SyntheticGesturePacket& gesture_packet) {
   // Only allow untrustworthy gestures if explicitly enabled.
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           cc::switches::kEnableGpuBenchmarking)) {
     bad_message::ReceivedBadMessage(GetProcess(),
                                     bad_message::RWH_SYNTHETIC_GESTURE);
     return;
   }
 
+  if (gesture_packet.gesture_params()->GetGestureType() ==
+      SyntheticGestureParams::POINTER_ACTION) {
+    QueueSyntheticPointerAction(
+        *SyntheticPointerActionParams::Cast(gesture_packet.gesture_params()),
+        base::Bind(&RenderWidgetHostImpl::OnSyntheticPointerActionCompleted,
+                   weak_factory_.GetWeakPtr()));
+    return;
+  }
+
   QueueSyntheticGesture(
         SyntheticGesture::Create(*gesture_packet.gesture_params()),
         base::Bind(&RenderWidgetHostImpl::OnSyntheticGestureCompleted,
                    weak_factory_.GetWeakPtr()));
 }
 
 void RenderWidgetHostImpl::OnSetCursor(const WebCursor& cursor) {
   SetCursor(cursor);
 }
 
@@ skipping 244 matching lines @@
   } else if (type == UNEXPECTED_EVENT_TYPE) {
     suppress_next_char_events_ = false;
   }
 }
 
 void RenderWidgetHostImpl::OnSyntheticGestureCompleted(
     SyntheticGesture::Result result) {
   Send(new InputMsg_SyntheticGestureCompleted(GetRoutingID()));
 }
 
+void RenderWidgetHostImpl::OnSyntheticPointerActionCompleted(
+    SyntheticGesture::Result result) {
+  if (result == SyntheticGesture::POINTER_ACTION_FINISHED) {
+    if (synthetic_gesture_controller_)
+      synthetic_gesture_controller_->ResetSyntheticPointer();
+    Send(new InputMsg_SyntheticGestureCompleted(GetRoutingID()));
+  }
+}
+
 bool RenderWidgetHostImpl::ShouldDropInputEvents() const {
   return ignore_input_events_ || process_->IgnoreInputEvents() || !delegate_;
 }
 
 void RenderWidgetHostImpl::SetBackgroundOpaque(bool opaque) {
   Send(new ViewMsg_SetBackgroundOpaque(GetRoutingID(), opaque));
 }
 
 void RenderWidgetHostImpl::SetEditCommandsForNextKeyEvent(
     const std::vector<EditCommand>& commands) {
@@ skipping 186 matching lines @@
   return delegate_ ? delegate_->GetRootBrowserAccessibilityManager() : NULL;
 }
 
 BrowserAccessibilityManager*
     RenderWidgetHostImpl::GetOrCreateRootBrowserAccessibilityManager() {
   return delegate_ ?
       delegate_->GetOrCreateRootBrowserAccessibilityManager() : NULL;
 }
 
 }  // namespace content