ash/desktop_background/desktop_background_widget_controller.h

   1 // Copyright (c) 2012 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 ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_WIDGET_CONTROLLER_H_
   6 #define ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_WIDGET_CONTROLLER_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ui/aura/window.h"
  11 #include "ui/compositor/layer.h"
  12 #include "ui/views/widget/widget.h"
  13 #include "ui/views/widget/widget_observer.h"
  14
  15 namespace ash {
  16 namespace internal {
  17
  18 // This class hides difference between two possible background implementations:
  19 // effective Layer-based for solid color, and Widget-based for images.
  20 // DesktopBackgroundWidgetController is installed as an owned property on the
  21 // RootWindow. To avoid a white flash during wallpaper changes the old
  22 // DesktopBackgroundWidgetController is moved to a secondary property
  23 // (kComponentWrapper). When the animation completes the old
  24 // DesktopBackgroundWidgetController is destroyed. Exported for tests.
  25 class ASH_EXPORT DesktopBackgroundWidgetController
  26     : public views::WidgetObserver {
  27  public:
  28   // Create
  29   explicit DesktopBackgroundWidgetController(views::Widget* widget);
  30   explicit DesktopBackgroundWidgetController(ui::Layer* layer);
  31
  32   virtual ~DesktopBackgroundWidgetController();
  33
  34   // Overridden from views::WidgetObserver.
  35   virtual void OnWidgetDestroying(views::Widget* widget) OVERRIDE;
  36
  37   // Set bounds of component that draws background.
  38   void SetBounds(gfx::Rect bounds);
  39
  40   // Move component from |src_container| in |root_window| to |dest_container|.
  41   // It is required for lock screen, when we need to move background so that
  42   // it hides user's windows. Returns true if there was something to reparent.
  43   bool Reparent(aura::RootWindow* root_window,
  44                 int src_container,
  45                 int dest_container);
  46
  47   views::Widget* widget() { return widget_; }
  48   ui::Layer* layer() { return layer_.get(); }
  49
  50  private:
  51   views::Widget* widget_;
  52   scoped_ptr<ui::Layer> layer_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundWidgetController);
  55 };
  56
  57 // This class wraps a DesktopBackgroundWidgetController pointer. It is installed
  58 // as an owned property on the RootWindow. DesktopBackgroundWidgetController is
  59 // moved to this property before animation completes. After animation completes,
  60 // the kDesktopController property on RootWindow is set to the
  61 // DesktopBackgroundWidgetController in this class. Exported for tests.
  62 class ASH_EXPORT AnimatingDesktopController {
  63  public:
  64   explicit AnimatingDesktopController(
  65       DesktopBackgroundWidgetController* component);
  66   ~AnimatingDesktopController();
  67
  68   // Stops animation and makes sure OnImplicitAnimationsCompleted() is called if
  69   // current animation is not finished yet.
  70   // Note we have to make sure this function is called before we set
  71   // kAnimatingDesktopController to a new controller. If it is not called, the
  72   // animating widget/layer is closed immediately and the new one is animating
  73   // from the widget/layer before animation. For instance, if a user quickly
  74   // switches between red, green and blue wallpapers. The green wallpaper will
  75   // first fade in from red wallpaper. And in the middle of the animation, blue
  76   // wallpaper also wants to fade in. If the green wallpaper animation does not
  77   // finish immediately, the green wallpaper widget will be removed and the red
  78   // widget will show again. As a result, the blue wallpaper fades in from red
  79   // wallpaper. This is a bad user experience. See bug http://crbug.com/156542
  80   // for more details.
  81   void StopAnimating();
  82
  83   // Gets the wrapped DesktopBackgroundWidgetController pointer. Caller should
  84   // take ownership of the pointer if |pass_ownership| is true.
  85   DesktopBackgroundWidgetController* GetController(bool pass_ownership);
  86
  87  private:
  88   scoped_ptr<DesktopBackgroundWidgetController> controller_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(AnimatingDesktopController);
  91 };
  92
  93 // Window property key, that binds instance of DesktopBackgroundWidgetController
  94 // to root windows.  Owned property.
  95 ASH_EXPORT extern
  96     const aura::WindowProperty<DesktopBackgroundWidgetController*>* const
  97         kDesktopController;
  98
  99 // Wrapper for the DesktopBackgroundWidgetController for a desktop background
 100 // that is animating in.  Owned property.
 101 ASH_EXPORT extern const aura::WindowProperty<AnimatingDesktopController*>* const
 102     kAnimatingDesktopController;
 103
 104 }  // namespace internal
 105 }  // namespace ash
 106
 107 #endif  // ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_WIDGET_CONTROLLER_H_