1// Copyright (c) 2011 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. 4 5#ifndef UI_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_ 6#define UI_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_ 7 8#include "base/basictypes.h" 9#include "base/observer_list.h" 10#include "ui/gfx/native_widget_types.h" 11#include "ui/views/views_export.h" 12 13template <typename T> struct DefaultSingletonTraits; 14 15namespace views { 16 17// This interface should be implemented by classes that want to be notified when 18// the native focus is about to change. Listeners implementing this interface 19// will be invoked for all native focus changes across the entire Chrome 20// application. FocusChangeListeners are only called for changes within the 21// children of a single top-level native-view. 22class WidgetFocusChangeListener { 23 public: 24 virtual void OnNativeFocusChange(gfx::NativeView focused_before, 25 gfx::NativeView focused_now) = 0; 26 27 protected: 28 virtual ~WidgetFocusChangeListener() {} 29}; 30 31class VIEWS_EXPORT WidgetFocusManager { 32 public: 33 // Returns the singleton instance. 34 static WidgetFocusManager* GetInstance(); 35 36 // Adds/removes a WidgetFocusChangeListener |listener| to the set of 37 // active listeners. 38 void AddFocusChangeListener(WidgetFocusChangeListener* listener); 39 void RemoveFocusChangeListener(WidgetFocusChangeListener* listener); 40 41 // To be called when native-focus shifts from |focused_before| to 42 // |focused_now|. 43 // TODO(port) : Invocations to this routine are only implemented for 44 // the Win32 platform. Calls need to be placed appropriately for 45 // non-Windows environments. 46 void OnWidgetFocusEvent(gfx::NativeView focused_before, 47 gfx::NativeView focused_now); 48 49 // Enable/Disable notification of registered listeners during calls 50 // to OnWidgetFocusEvent. Used to prevent unwanted focus changes from 51 // propagating notifications. 52 void EnableNotifications() { enabled_ = true; } 53 void DisableNotifications() { enabled_ = false; } 54 55 private: 56 friend struct DefaultSingletonTraits<WidgetFocusManager>; 57 58 WidgetFocusManager(); 59 ~WidgetFocusManager(); 60 61 ObserverList<WidgetFocusChangeListener> focus_change_listeners_; 62 63 bool enabled_; 64 65 DISALLOW_COPY_AND_ASSIGN(WidgetFocusManager); 66}; 67 68// A basic helper class that is used to disable native focus change 69// notifications within a scope. 70class VIEWS_EXPORT AutoNativeNotificationDisabler { 71 public: 72 AutoNativeNotificationDisabler(); 73 ~AutoNativeNotificationDisabler(); 74 75 private: 76 DISALLOW_COPY_AND_ASSIGN(AutoNativeNotificationDisabler); 77}; 78 79} // namespace views 80 81#endif // UI_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_ 82