system_background_controller.h revision 7d4cd473f85ac64c3747c96c277f9e506a0d2246 
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/window_observer.h"
15
16namespace aura {
17class RootWindow;
18}
19
20namespace ui {
21class Layer;
22}
23
24namespace ash {
25namespace 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.
33class SystemBackgroundController : public aura::WindowObserver {
34 public:
35  SystemBackgroundController(aura::RootWindow* root_window, SkColor color);
36  virtual ~SystemBackgroundController();
37
38  void SetColor(SkColor color);
39
40  // aura::WindowObserver overrides:
41  virtual void OnWindowBoundsChanged(aura::Window* root,
42                                     const gfx::Rect& old_bounds,
43                                     const gfx::Rect& new_bounds) OVERRIDE;
44
45 private:
46  class HostContentLayerDelegate;
47
48  aura::RootWindow* root_window_;  // not owned
49
50  scoped_ptr<ui::Layer> layer_;
51
52  DISALLOW_COPY_AND_ASSIGN(SystemBackgroundController);
53};
54
55}  // namespace internal
56}  // namespace ash
57
58#endif  // ASH_WM_SYSTEM_BACKGROUND_CONTROLLER_H_
59