components/mus/view_tree_host_delegate.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_VIEW_TREE_HOST_DELEGATE_H_
   6 #define COMPONENTS_MUS_VIEW_TREE_HOST_DELEGATE_H_
   7
   8 namespace mus {
   9
  10 class ViewTreeImpl;
  11
  12 // A ViewTreeHostDelegate interface is implemented by an object that
  13 // has the ViewTreeImpl that is associated with the ViewTreeHostImpl that holds
  14 // a pointer to this object. Typically, a ViewTreeHostDelegate will also manage
  15 // the lifetime of the ViewTreeHostImpl and will delete the object when it gets
  16 // informed of when the Display of the root is closed.
  17 class ViewTreeHostDelegate {
  18  public:
  19   // Called when the window associated with the root is completely initialized
  20   // (i.e. the ViewportMetrics for the display is known).
  21   virtual void OnDisplayInitialized() = 0;
  22
  23   // Called when the window associated with the root is closed.
  24   virtual void OnDisplayClosed() = 0;
  25
  26   // Returns the ViewTreeImpl associated with the delegate.
  27   virtual ViewTreeImpl* GetViewTree() = 0;
  28
  29  protected:
  30   virtual ~ViewTreeHostDelegate() {}
  31 };
  32
  33 }  // namespace mus
  34
  35 #endif  // COMPONENTS_MUS_VIEW_TREE_HOST_DELEGATE_H_