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 class RootWindowController;
  17
  18 // This class implements a widget-based wallpaper.
  19 // DesktopBackgroundWidgetController is owned by RootWindowController.
  20 // When the animation completes the old DesktopBackgroundWidgetController is
  21 // destroyed. Exported for tests.
  22 class ASH_EXPORT DesktopBackgroundWidgetController
  23     : public views::WidgetObserver {
  24  public:
  25   // Create
  26   explicit DesktopBackgroundWidgetController(views::Widget* widget);
  27
  28   virtual ~DesktopBackgroundWidgetController();
  29
  30   // Overridden from views::WidgetObserver.
  31   virtual void OnWidgetDestroying(views::Widget* widget) OVERRIDE;
  32
  33   // Set bounds of component that draws background.
  34   void SetBounds(gfx::Rect bounds);
  35
  36   // Move component from |src_container| in |root_window| to |dest_container|.
  37   // It is required for lock screen, when we need to move background so that
  38   // it hides user's windows. Returns true if there was something to reparent.
  39   bool Reparent(aura::Window* root_window,
  40                 int src_container,
  41                 int dest_container);
  42
  43   // Starts wallpaper fade in animation. |root_window_controller| is
  44   // the root window where the animation will happen. (This is
  45   // necessary this as |layer_| doesn't have access to the root window).
  46   void StartAnimating(RootWindowController* root_window_controller);
  47
  48   views::Widget* widget() { return widget_; }
  49
  50  private:
  51   views::Widget* widget_;
  52
  53   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundWidgetController);
  54 };
  55
  56 // This class wraps a DesktopBackgroundWidgetController pointer. It is owned
  57 // by RootWindowController. The instance of DesktopBackgroundWidgetController is
  58 // moved to this RootWindowController when the animation completes.
  59 // Exported for tests.
  60 class ASH_EXPORT AnimatingDesktopController {
  61  public:
  62   explicit AnimatingDesktopController(
  63       DesktopBackgroundWidgetController* component);
  64   ~AnimatingDesktopController();
  65
  66   // Stops animation and makes sure OnImplicitAnimationsCompleted() is called if
  67   // current animation is not finished yet.
  68   // Note we have to make sure this function is called before we set
  69   // kAnimatingDesktopController to a new controller. If it is not called, the
  70   // animating widget/layer is closed immediately and the new one is animating
  71   // from the widget/layer before animation. For instance, if a user quickly
  72   // switches between red, green and blue wallpapers. The green wallpaper will
  73   // first fade in from red wallpaper. And in the middle of the animation, blue
  74   // wallpaper also wants to fade in. If the green wallpaper animation does not
  75   // finish immediately, the green wallpaper widget will be removed and the red
  76   // widget will show again. As a result, the blue wallpaper fades in from red
  77   // wallpaper. This is a bad user experience. See bug http://crbug.com/156542
  78   // for more details.
  79   void StopAnimating();
  80
  81   // Gets the wrapped DesktopBackgroundWidgetController pointer. Caller should
  82   // take ownership of the pointer if |pass_ownership| is true.
  83   DesktopBackgroundWidgetController* GetController(bool pass_ownership);
  84
  85  private:
  86   scoped_ptr<DesktopBackgroundWidgetController> controller_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(AnimatingDesktopController);
  89 };
  90
  91 }  // namespace ash
  92
  93 #endif  // ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_WIDGET_CONTROLLER_H_