1 files changed, 48 insertions, 0 deletions
diff --git a/app/active_window_watcher_x.h b/app/active_window_watcher_x.h
new file mode 100644
index 0000000..2ea524e
--- /dev/null
+++ b/app/active_window_watcher_x.h
@@ -0,0 +1,48 @@
+// Copyright (c) 2009 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.
+
+#ifndef APP_ACTIVE_WINDOW_WATCHER_X_H_
+#define APP_ACTIVE_WINDOW_WATCHER_X_H_
+
+#include <gdk/gdk.h>
+
+#include "base/basictypes.h"
+#include "base/observer_list.h"
+#include "base/singleton.h"
+
+// This is a helper class that is used to keep track of which window the X
+// window manager thinks is active. Add an Observer to listener for changes to
+// the active window.
+class ActiveWindowWatcherX {
+ public:
+  class Observer {
+   public:
+    virtual void ActiveWindowChanged(GdkWindow* active_window) = 0;
+  };
+
+  static void AddObserver(Observer* observer);
+  static void RemoveObserver(Observer* observer);
+
+ private:
+  friend struct DefaultSingletonTraits<ActiveWindowWatcherX>;
+
+  ActiveWindowWatcherX();
+
+  void Init();
+
+  // Sends a notification out through the NotificationService that the active
+  // window has changed.
+  void NotifyActiveWindowChanged();
+
+  // Callback for PropertyChange XEvents.
+  static GdkFilterReturn OnWindowXEvent(GdkXEvent* xevent,
+                                        GdkEvent* event,
+                                        gpointer window_watcher);
+
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ActiveWindowWatcherX);
+};
+
+#endif  // APP_ACTIVE_WINDOW_WATCHER_X_H_