Aura on Linux: Make a DesktopScreenX11 to match the windows one.

ui/aura/root_window_host_linux.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 "ui/aura/root_window_host_linux.h"
 
 #include <X11/Xatom.h>
 #include <X11/cursorfont.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/extensions/Xfixes.h>
 #include <X11/extensions/Xrandr.h>
 #include <algorithm>
 
 #include "base/message_pump_x.h"
 #include "base/stl_util.h"
 #include "base/stringprintf.h"
 #include "ui/aura/client/user_gesture_client.h"
 #include "ui/aura/dispatcher_linux.h"
 #include "ui/aura/env.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/keycodes/keyboard_codes.h"
 #include "ui/base/touch/touch_factory.h"
 #include "ui/base/x/x11_util.h"
+#include "ui/base/view_prop.h"
 #include "ui/gfx/compositor/layer.h"
 
 using std::max;
 using std::min;
 
 namespace aura {
 
 namespace {
 
 // Standard Linux mouse buttons for going back and forward.
 const int kBackMouseButton = 8;
 const int kForwardMouseButton = 9;
 
+const char* kRootWindowHostLinuxKey = "__AURA_ROOT_WINDOW_HOST_LINUX__";

[Daniel Erat, 2012/05/01 22:51:48]

nit: i think that "const char kRootWindowHostLinuxKey[]" is slightly preferred,
as it prevents reassignment

+
 // The events reported for slave devices can have incorrect information for some
 // fields. This utility function is used to check for such inconsistencies.
 void CheckXEventForConsistency(XEvent* xevent) {
   static bool expect_master_event = false;
   static XIDeviceEvent slave_event;
   static gfx::Point slave_location;
   static int slave_button;
 
   // Note: If an event comes from a slave pointer device, then it will be
   // followed by the same event, but reported from its master pointer device.
@@ skipping 258 matching lines @@
       bounds.x(), bounds.y(), bounds.width(), bounds.height(),
       0,               // border width
       CopyFromParent,  // depth
       InputOutput,
       CopyFromParent,  // visual
       CWBackPixmap,
       &swa);
   static_cast<DispatcherLinux*>(Env::GetInstance()->GetDispatcher())->
       WindowDispatcherCreated(xwindow_, this);
 
+  prop_.reset(new ui::ViewProp(xwindow_, kRootWindowHostLinuxKey, this));
+
   long event_mask = ButtonPressMask | ButtonReleaseMask | FocusChangeMask |
                     KeyPressMask | KeyReleaseMask |
                     EnterWindowMask | LeaveWindowMask |
                     ExposureMask | VisibilityChangeMask |
                     StructureNotifyMask | PropertyChangeMask |
                     PointerMotionMask;
   XSelectInput(xdisplay_, xwindow_, event_mask);
   XFlush(xdisplay_);
 
   if (base::MessagePumpForUI::HasXInput2())
@@ skipping 472 matching lines @@
 }
 
 // static
 RootWindowHost* RootWindowHost::Create(const gfx::Rect& bounds) {
   return new RootWindowHostLinux(bounds);
 }
 
 // static
 RootWindowHost* RootWindowHost::GetForAcceleratedWidget(
     gfx::AcceleratedWidget accelerated_widget) {
-  NOTIMPLEMENTED();
-  return NULL;  // TODO(erg): implement if necessary or remove this comment.
+  return reinterpret_cast<RootWindowHost*>(
+      ui::ViewProp::GetValue(accelerated_widget, kRootWindowHostLinuxKey));
 }
 
 // static
 gfx::Size RootWindowHost::GetNativeScreenSize() {
   ::Display* xdisplay = base::MessagePumpX::GetDefaultXDisplay();
   return gfx::Size(DisplayWidth(xdisplay, 0), DisplayHeight(xdisplay, 0));
 }
 
 }  // namespace aura