It is time.

ui/views/focus/widget_focus_manager.h

-// Copyright (c) 2011 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_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_
-#define UI_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_
-
-#include "base/basictypes.h"
-#include "base/observer_list.h"
-#include "ui/gfx/native_widget_types.h"
-#include "ui/views/views_export.h"
-
-template <typename T> struct DefaultSingletonTraits;
-
-namespace views {
-
-// This interface should be implemented by classes that want to be notified when
-// the native focus is about to change.  Listeners implementing this interface
-// will be invoked for all native focus changes across the entire Chrome
-// application.  FocusChangeListeners are only called for changes within the
-// children of a single top-level native-view.
-class WidgetFocusChangeListener {
- public:
-  virtual void OnNativeFocusChange(gfx::NativeView focused_before,
-                                   gfx::NativeView focused_now) = 0;
-
- protected:
-  virtual ~WidgetFocusChangeListener() {}
-};
-
-class VIEWS_EXPORT WidgetFocusManager {
- public:
-  // Returns the singleton instance.
-  static WidgetFocusManager* GetInstance();
-
-  // Adds/removes a WidgetFocusChangeListener |listener| to the set of
-  // active listeners.
-  void AddFocusChangeListener(WidgetFocusChangeListener* listener);
-  void RemoveFocusChangeListener(WidgetFocusChangeListener* listener);
-
-  // To be called when native-focus shifts from |focused_before| to
-  // |focused_now|.
-  // TODO(port) : Invocations to this routine are only implemented for
-  // the Win32 platform.  Calls need to be placed appropriately for
-  // non-Windows environments.
-  void OnWidgetFocusEvent(gfx::NativeView focused_before,
-                          gfx::NativeView focused_now);
-
-  // Enable/Disable notification of registered listeners during calls
-  // to OnWidgetFocusEvent.  Used to prevent unwanted focus changes from
-  // propagating notifications.
-  void EnableNotifications() { enabled_ = true; }
-  void DisableNotifications() { enabled_ = false; }
-
- private:
-  friend struct DefaultSingletonTraits<WidgetFocusManager>;
-
-  WidgetFocusManager();
-  ~WidgetFocusManager();
-
-  ObserverList<WidgetFocusChangeListener> focus_change_listeners_;
-
-  bool enabled_;
-
-  DISALLOW_COPY_AND_ASSIGN(WidgetFocusManager);
-};
-
-// A basic helper class that is used to disable native focus change
-// notifications within a scope.
-class VIEWS_EXPORT AutoNativeNotificationDisabler {
- public:
-  AutoNativeNotificationDisabler();
-  ~AutoNativeNotificationDisabler();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(AutoNativeNotificationDisabler);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_