1 files changed, 45 insertions, 0 deletions
diff --git a/ui/wm/public/activation_change_observer.h b/ui/wm/public/activation_change_observer.h
new file mode 100644
index 0000000..68d5b8a
--- /dev/null
+++ b/ui/wm/public/activation_change_observer.h
@@ -0,0 +1,45 @@
+// 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.
+
+#ifndef UI_WM_PUBLIC_ACTIVATION_CHANGE_OBSERVER_H_
+#define UI_WM_PUBLIC_ACTIVATION_CHANGE_OBSERVER_H_
+
+#include "ui/aura/aura_export.h"
+
+namespace aura {
+class Window;
+
+namespace client {
+
+class AURA_EXPORT ActivationChangeObserver {
+ public:
+  // Called when |active| gains focus, or there is no active window
+  // (|active| is NULL in this case.) |old_active| refers to the
+  // previous active window or NULL if there was no previously active
+  // window.
+  virtual void OnWindowActivated(Window* gained_active,
+                                 Window* lost_active) = 0;
+
+  // Called when during window activation the currently active window is
+  // selected for activation. This can happen when a window requested for
+  // activation cannot be activated because a system modal window is active.
+  virtual void OnAttemptToReactivateWindow(aura::Window* request_active,
+                                           aura::Window* actual_active) {}
+
+ protected:
+  virtual ~ActivationChangeObserver() {}
+};
+
+// Gets/Sets the ActivationChangeObserver for a specific window. This observer
+// is notified after the ActivationClient notifies all registered observers.
+AURA_EXPORT void SetActivationChangeObserver(
+    Window* window,
+    ActivationChangeObserver* observer);
+AURA_EXPORT ActivationChangeObserver* GetActivationChangeObserver(
+    Window* window);
+
+}  // namespace client
+}  // namespace aura
+
+#endif  // UI_WM_PUBLIC_ACTIVATION_CHANGE_OBSERVER_H_