Hide the cursor on the client when it is hidden on the host

remoting/host/chromeos/mouse_cursor_monitor_aura.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 "remoting/host/chromeos/mouse_cursor_monitor_aura.h"
 
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "remoting/host/chromeos/skia_bitmap_desktop_frame.h"
 #include "third_party/webrtc/modules/desktop_capture/mouse_cursor.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/cursor/cursors_aura.h"
 
+namespace {
+
+// Creates an empty webrtc::MouseCursor. The caller is responsible for
+// destroying the returned cursor.
+webrtc::MouseCursor* CreateEmptyMouseCursor() {
+  return new webrtc::MouseCursor(
+      new webrtc::BasicDesktopFrame(webrtc::DesktopSize(0, 0)),
+      webrtc::DesktopVector(0, 0));
+}
+
+}  // namespace
+
 namespace remoting {
 
 MouseCursorMonitorAura::MouseCursorMonitorAura()
     : callback_(nullptr),
       mode_(SHAPE_AND_POSITION) {
 }
 
 void MouseCursorMonitorAura::Init(Callback* callback, Mode mode) {
   DCHECK(!callback_);
   DCHECK(callback);
 
   callback_ = callback;
   mode_ = mode;
 }
 
 void MouseCursorMonitorAura::Capture() {
   // Check if the cursor is different.
   gfx::NativeCursor cursor =
       ash::Shell::GetPrimaryRootWindow()->GetHost()->last_cursor();
 
   if (cursor != last_cursor_) {
+    last_cursor_ = cursor;
     NotifyCursorChanged(cursor);
   }
 
   // Check if we need to update the location.
   if (mode_ == SHAPE_AND_POSITION) {
     gfx::Point position = aura::Env::GetInstance()->last_mouse_location();
     if (position != last_mouse_location_) {
       last_mouse_location_ = position;
       callback_->OnMouseCursorPosition(
           INSIDE, webrtc::DesktopVector(position.x(), position.y()));
     }
   }
 }
 
 void MouseCursorMonitorAura::NotifyCursorChanged(const ui::Cursor& cursor) {
   scoped_ptr<SkBitmap> cursor_bitmap(new SkBitmap());
   gfx::Point cursor_hotspot;
+
+  if (cursor.native_type() == ui::kCursorNone) {
+    callback_->OnMouseCursor(CreateEmptyMouseCursor());
+    return;
+  }
+
   if (!ui::GetCursorBitmap(cursor, cursor_bitmap.get(), &cursor_hotspot)) {
     LOG(ERROR) << "Failed to load bitmap for cursor type:"
                << cursor.native_type();
+    callback_->OnMouseCursor(CreateEmptyMouseCursor());
     return;
   }
 
-  last_cursor_ = cursor;
-
   // There is a bug (crbug.com/436993) in aura::GetCursorBitmap() such that it
   // it would return a scale-factor-100 bitmap with a scale-factor-200 hotspot.
   // This causes the hotspot to go out of range.  As a result, we would need to
   // manually downscale the hotspot.
   float scale_factor = cursor.device_scale_factor();
   cursor_hotspot.SetPoint(cursor_hotspot.x() / scale_factor,
                           cursor_hotspot.y() / scale_factor);
 
   if (cursor_hotspot.x() >= cursor_bitmap->width() ||
       cursor_hotspot.y() >= cursor_bitmap->height()) {
     LOG(WARNING) << "Cursor hotspot is out of bounds for type: "
                  << cursor.native_type() << ".  Setting to (0,0) instead";
     cursor_hotspot.SetPoint(0, 0);
   }
 
   scoped_ptr<webrtc::DesktopFrame> image(
       SkiaBitmapDesktopFrame::Create(cursor_bitmap.Pass()));
   scoped_ptr<webrtc::MouseCursor> cursor_shape(new webrtc::MouseCursor(
       image.release(),
       webrtc::DesktopVector(cursor_hotspot.x(), cursor_hotspot.y())));
 
   callback_->OnMouseCursor(cursor_shape.release());
 }
 
 }  // namespace remoting