Fixing the Position of Context Menu for BrowserPlugin (<webview>)

content/browser/frame_host/render_widget_host_view_guest.cc

 // Copyright 2014 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 "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_factory.h"
@@ skipping 607 matching lines @@
   return static_cast<RenderWidgetHostViewBase*>(
       guest_->GetOwnerRenderWidgetHostView());
 }
 
 void RenderWidgetHostViewGuest::OnHandleInputEvent(
     RenderWidgetHostImpl* embedder,
     int browser_plugin_instance_id,
     const gfx::Rect& guest_window_rect,
     const blink::WebInputEvent* event) {
   if (blink::WebInputEvent::isMouseEventType(event->type)) {
-    host_->ForwardMouseEvent(
-        *static_cast<const blink::WebMouseEvent*>(event));
+    // The mouse events are subject to whatever CSS transforms
+    // applied on the BrowserPlugin. This causes the reported position of
+    // ContextMenu from the guest renderer become potentially incorrect. As a

[wjmaclean, 2015/08/17 13:05:23]

-> "... renderer to potentially be incorrect."

[Ehsaan, 2015/08/17 14:09:12]

Done.

+    // hack, the position is calculated here and reported to the
+    // BrowserPluginGuest.
+    const blink::WebMouseEvent& mouse_event =
+        static_cast<const blink::WebMouseEvent&>(*event);
+    // A MouseDown on the ButtonRight could suggest a ContextMenu.
+    if (guest_
+        && mouse_event.type == blink::WebInputEvent::MouseDown
+        && mouse_event.button == blink::WebPointerProperties::ButtonRight)      
+      guest_->SetContextMenuPosition(

[wjmaclean, 2015/08/17 13:05:23]

Will the transformation ever be more than just a translation? Will scale and/or
rotation ever be an issue?

[Ehsaan, 2015/08/17 14:09:12]

This translation is based on globalX/Y which is supposed to be untouched, plus
the corner point of the view. This should become the value where the context
menu was supposed to be shown. I am doing this on the browser side to avoid the
CSS transformations. The way it normally work is for the renderer to undo the
transforms is here (I guess):
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

Which is not done (and should not be I believe) in the case of BrowserPlugin.
This even is supposed to be carried to the guest renderer and changing the
coordinates at the renderer side will break functionality.

+          gfx::Point(mouse_event.globalX - GetViewBounds().x(),
+                     mouse_event.globalY - GetViewBounds().y()));
+    host_->ForwardMouseEvent(mouse_event);
     return;
   }
 
   if (event->type == blink::WebInputEvent::MouseWheel) {
     host_->ForwardWheelEvent(
         *static_cast<const blink::WebMouseWheelEvent*>(event));
     return;
   }
 
   if (blink::WebInputEvent::isKeyboardEventType(event->type)) {
@@ skipping 17 matching lines @@
   }
 
   if (blink::WebInputEvent::isGestureEventType(event->type)) {
     host_->ForwardGestureEvent(
         *static_cast<const blink::WebGestureEvent*>(event));
     return;
   }
 }
 
 }  // namespace content