components/mus/server_view_drawn_tracker_observer.h

   1 // Copyright 2015 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 COMPONENTS_MUS_SERVER_VIEW_DRAWN_TRACKER_OBSERVER_H_
   6 #define COMPONENTS_MUS_SERVER_VIEW_DRAWN_TRACKER_OBSERVER_H_
   7
   8 namespace mus {
   9
  10 class ServerView;
  11
  12 class ServerViewDrawnTrackerObserver {
  13  public:
  14   // Invoked when the drawn state changes. If |is_drawn| is false |ancestor|
  15   // identifies where the change occurred. In the case of a remove |ancestor| is
  16   // the parent of the view that was removed. In the case of a visibility change
  17   // |ancestor| is the parent of the view whose visibility changed.
  18   virtual void OnDrawnStateChanged(ServerView* ancestor,
  19                                    ServerView* view,
  20                                    bool is_drawn) {}
  21
  22  protected:
  23   virtual ~ServerViewDrawnTrackerObserver() {}
  24 };
  25
  26 }  // namespace mus
  27
  28 #endif  // COMPONENTS_MUS_SERVER_VIEW_DRAWN_TRACKER_OBSERVER_H_