ash/wm/system_background_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_SYSTEM_BACKGROUND_CONTROLLER_H_
   6 #define ASH_WM_SYSTEM_BACKGROUND_CONTROLLER_H_
   7
   8 #include <string>
   9
  10 #include "ash/ash_export.h"
  11 #include "base/basictypes.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "third_party/skia/include/core/SkColor.h"
  14 #include "ui/aura/root_window_observer.h"
  15
  16 namespace aura {
  17 class RootWindow;
  18 }
  19
  20 namespace ui {
  21 class Layer;
  22 }
  23
  24 namespace ash {
  25 namespace internal {
  26
  27 // SystemBackgroundController manages a ui::Layer that's stacked at the bottom
  28 // of an aura::RootWindow's children.  It exists solely to obscure portions of
  29 // the root layer that aren't covered by any other layers (e.g. before the
  30 // desktop background image is loaded at startup, or when we scale down all of
  31 // the other layers as part of a power-button or window-management animation).
  32 // It should never be transformed or restacked.
  33 class SystemBackgroundController : public aura::RootWindowObserver {
  34  public:
  35   SystemBackgroundController(aura::RootWindow* root_window, SkColor color);
  36   virtual ~SystemBackgroundController();
  37
  38   void SetColor(SkColor color);
  39
  40   // aura::RootWindowObserver overrides:
  41   virtual void OnRootWindowResized(const aura::RootWindow* root,
  42                                    const gfx::Size& old_size) OVERRIDE;
  43
  44  private:
  45   class HostContentLayerDelegate;
  46
  47   aura::RootWindow* root_window_;  // not owned
  48
  49   scoped_ptr<ui::Layer> layer_;
  50
  51   DISALLOW_COPY_AND_ASSIGN(SystemBackgroundController);
  52 };
  53
  54 }  // namespace internal
  55 }  // namespace ash
  56
  57 #endif  // ASH_WM_SYSTEM_BACKGROUND_CONTROLLER_H_