ash/wm/workspace/desktop_background_fade_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_WM_WORKSPACE_DESKTOP_BACKGROUND_FADE_CONTROLLER_H_
   6 #define ASH_WM_WORKSPACE_DESKTOP_BACKGROUND_FADE_CONTROLLER_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "base/basictypes.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "ui/compositor/layer_animation_observer.h"
  12
  13 namespace aura {
  14 class Window;
  15 }
  16
  17 namespace base {
  18 class TimeDelta;
  19 }
  20
  21 namespace ash {
  22 namespace internal {
  23
  24 class ColoredWindowController;
  25
  26 // DesktopBackgroundFadeController handles fading in or out the desktop. It is
  27 // used when maximizing or restoring a window. It is implemented as a colored
  28 // layer whose opacity varies. This results in fading in or out all the windows
  29 // the DesktopBackgroundFadeController is placed on top of. This is used
  30 // instead of varying the opacity for two reasons:
  31 // . The window showing background and the desktop workspace do not have a
  32 //   common parent that can be animated. This could be fixed, but wouldn't
  33 //   address the following.
  34 // . When restoring the window is moved back to the desktop workspace. If we
  35 //   animated the opacity of the desktop workspace the cross fade would be
  36 //   effected.
  37 class ASH_EXPORT DesktopBackgroundFadeController
  38     : public ui::ImplicitAnimationObserver {
  39  public:
  40   // Direction to fade.
  41   enum Direction {
  42     FADE_IN,
  43     FADE_OUT,
  44   };
  45
  46   // Creates a new DesktopBackgroundFadeController. |parent| is the Window to
  47 //   parent the newly created window to. The newly created window is stacked
  48 //   directly on top of |position_above|. The window animating the fade is
  49 //   destroyed as soon as the animation completes.
  50   DesktopBackgroundFadeController(aura::Window* parent,
  51                                   aura::Window* position_above,
  52                                   base::TimeDelta duration,
  53                                   Direction direction);
  54   virtual ~DesktopBackgroundFadeController();
  55
  56  private:
  57   // ImplicitAnimationObserver overrides:
  58   virtual void OnImplicitAnimationsCompleted() OVERRIDE;
  59
  60   scoped_ptr<ColoredWindowController> window_controller_;
  61
  62   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundFadeController);
  63 };
  64
  65 }  // namespace internal
  66 }  // namespace ash
  67
  68 #endif  // ASH_WM_WORKSPACE_DESKTOP_BACKGROUND_FADE_CONTROLLER_H_