ui/views/widget/widget_removals_observer.h

   1 // Copyright 2014 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_WIDGET_WIDGET_REMOVALS_OBSERVER_H_
   6 #define UI_VIEWS_WIDGET_WIDGET_REMOVALS_OBSERVER_H_
   7
   8 #include "ui/views/views_export.h"
   9
  10 namespace views {
  11
  12 class Widget;
  13 class View;
  14
  15 // |WidgetRemovalsObserver| complements |WidgetObserver| with additional
  16 // notifications. These include events occurring during tear down like view
  17 // removal. For this reason, it is recommended that subclasses not also inherit
  18 // from |View|.
  19 class VIEWS_EXPORT WidgetRemovalsObserver {
  20  public:
  21   // Called immediately before a descendant view of |widget| is removed.
  22   virtual void OnWillRemoveView(Widget* widget, View* view) {}
  23
  24  protected:
  25   virtual ~WidgetRemovalsObserver() {}
  26 };
  27
  28 }  // namespace views
  29
  30 #endif  // UI_VIEWS_WIDGET_WIDGET_REMOVALS_OBSERVER_H_