exo: WMHelperMus: Hook up event handlers for mus+ash

components/exo/pointer.cc

 // Copyright 2015 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 "components/exo/pointer.h"
 
 #include "ash/common/display/display_info.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/display/display_manager.h"
 #include "components/exo/pointer_delegate.h"
@@ skipping 112 matching lines @@
 void Pointer::SetStylusDelegate(PointerStylusDelegate* delegate) {
   stylus_delegate_ = delegate;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ui::EventHandler overrides:
 
 void Pointer::OnMouseEvent(ui::MouseEvent* event) {
   Surface* target = GetEffectiveTargetForEvent(event);
 
+  if (target == surface_)

[reveman, 2016/08/22 13:41:42]

why is this needed?

[Peng, 2016/08/22 14:32:40]

I don't why, but on mus-ash, this surface_ will get mouse events. And I think
the surface_ is for showing cursor, so we shouldn't care about it, right?

[reveman, 2016/08/22 15:44:08]

correct this is the surface for the cursor sprite. however,
"params.accept_events = false" in Pointer::CreatePointerWidget should prevent
this from getting events dispatched to it. is that not the case for mus?

[Peng, 2016/08/22 16:15:14]

I think it must be a bug in mus+ash. I filed a bug for it and added a TODO here.

+    return;
+
   // If target is different than the current pointer focus then we need to
   // generate enter and leave events.
   if (target != focus_) {
     // First generate a leave event if we currently have a target in focus.
     if (focus_) {
       delegate_->OnPointerLeave(focus_);
       focus_->RemoveSurfaceObserver(this);
       // Require SetCursor() to be called and cursor to be re-defined in
       // response to each OnPointerEnter() call.
       focus_->UnregisterCursorProvider(this);
@@ skipping 209 matching lines @@
 
   if (ui_scale != cursor_scale_) {
     gfx::Transform transform;
     transform.Scale(ui_scale, ui_scale);
     widget_->GetNativeWindow()->SetTransform(transform);
     cursor_scale_ = ui_scale;
   }
 }
 
 }  // namespace exo