1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef UI_BASE_X_WORK_AREA_WATCHER_X_H_
6 #define UI_BASE_X_WORK_AREA_WATCHER_X_H_
8 #include "base/basictypes.h"
9 #include "base/observer_list.h"
10 #include "ui/base/ui_base_export.h"
11 #include "ui/base/x/x11_util.h"
13 template <typename T> struct DefaultSingletonTraits;
17 class WorkAreaWatcherObserver;
20 class RootWindowPropertyWatcherX;
23 // This is a helper class that is used to keep track of changes to work area.
24 // Add an observer to track changes.
25 class UI_BASE_EXPORT WorkAreaWatcherX {
27 static WorkAreaWatcherX* GetInstance();
28 static void AddObserver(WorkAreaWatcherObserver* observer);
29 static void RemoveObserver(WorkAreaWatcherObserver* observer);
32 friend struct DefaultSingletonTraits<WorkAreaWatcherX>;
33 friend class ui::internal::RootWindowPropertyWatcherX;
38 // Gets the atom for the default display for the property this class is
40 static Atom GetPropertyAtom();
42 // Notify observers that the work area has changed.
45 // Instance method that implements Notify().
46 void NotifyWorkAreaChanged();
48 ObserverList<WorkAreaWatcherObserver> observers_;
50 DISALLOW_COPY_AND_ASSIGN(WorkAreaWatcherX);
55 #endif // UI_BASE_X_WORK_AREA_WATCHER_X_H_