ui/views/widget/window_reorderer.h

   1 // Copyright 2013 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_WINDOW_REORDERER_H_
   6 #define UI_VIEWS_WIDGET_WINDOW_REORDERER_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ui/aura/window_observer.h"
  11
  12 namespace aura {
  13 class Window;
  14 }
  15
  16 namespace views {
  17 class View;
  18
  19 // Class which reorders the widget's child windows which have an associated view
  20 // in the widget's view tree according the z-order of the views in the view
  21 // tree. Windows not associated to a view are stacked above windows with an
  22 // associated view. The child windows' layers are additionally reordered
  23 // according to the z-order of the associated views relative to views with
  24 // layers.
  25 class WindowReorderer : public aura::WindowObserver {
  26  public:
  27   WindowReorderer(aura::Window* window, View* root_view);
  28   ~WindowReorderer() override;
  29
  30   // Explicitly reorder the children of |window_| (and their layers). This
  31   // method should be called when the position of a view with an associated
  32   // window changes in the view hierarchy. This method assumes that the
  33   // child layers of |window_| which are owned by views are already in the
  34   // correct z-order relative to each other and does no reordering if there
  35   // are no views with an associated window.
  36   void ReorderChildWindows();
  37
  38  private:
  39   // aura::WindowObserver overrides:
  40   void OnWindowAdded(aura::Window* new_window) override;
  41   void OnWillRemoveWindow(aura::Window* window) override;
  42   void OnWindowDestroying(aura::Window* window) override;
  43
  44   // The window and the root view of the native widget which owns the
  45   // WindowReorderer.
  46   aura::Window* parent_window_;
  47   View* root_view_;
  48
  49   // Reorders windows as a result of the kHostViewKey being set on a child of
  50   // |parent_window_|.
  51   class AssociationObserver;
  52   scoped_ptr<AssociationObserver> association_observer_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(WindowReorderer);
  55 };
  56
  57 }  // namespace views
  58
  59 #endif  // UI_VIEWS_WIDGET_WINDOW_REORDERER_H_