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 UI_WM_CORE_SHADOW_H_
6#define UI_WM_CORE_SHADOW_H_
7
8#include "base/basictypes.h"
9#include "base/memory/scoped_ptr.h"
10#include "ui/compositor/layer_animation_observer.h"
11#include "ui/gfx/rect.h"
12#include "ui/wm/wm_export.h"
13
14namespace ui {
15class Layer;
16}  // namespace ui
17
18namespace wm {
19
20class ImageGrid;
21
22// Simple class that draws a drop shadow around content at given bounds.
23class WM_EXPORT Shadow : public ui::ImplicitAnimationObserver {
24 public:
25  enum Style {
26    // Active windows have more opaque shadows, shifted down to make the window
27    // appear "higher".
28    STYLE_ACTIVE,
29
30    // Inactive windows have less opaque shadows.
31    STYLE_INACTIVE,
32
33    // Small windows like tooltips and context menus have lighter, smaller
34    // shadows.
35    STYLE_SMALL,
36  };
37
38  Shadow();
39  virtual ~Shadow();
40
41  void Init(Style style);
42
43  // Returns |image_grid_|'s ui::Layer.  This is exposed so it can be added to
44  // the same layer as the content and stacked below it.  SetContentBounds()
45  // should be used to adjust the shadow's size and position (rather than
46  // applying transformations to this layer).
47  ui::Layer* layer() const;
48
49  const gfx::Rect& content_bounds() const { return content_bounds_; }
50  Style style() const { return style_; }
51
52  // Moves and resizes |image_grid_| to frame |content_bounds|.
53  void SetContentBounds(const gfx::Rect& content_bounds);
54
55  // Sets the shadow's style, animating opacity as necessary.
56  void SetStyle(Style style);
57
58  // ui::ImplicitAnimationObserver overrides:
59  virtual void OnImplicitAnimationsCompleted() OVERRIDE;
60
61 private:
62  // Updates the |image_grid_| images to the current |style_|.
63  void UpdateImagesForStyle();
64
65  // Updates the |image_grid_| bounds based on its image sizes and the
66  // current |content_bounds_|.
67  void UpdateImageGridBounds();
68
69  // The current style, set when the transition animation starts.
70  Style style_;
71
72  scoped_ptr<ImageGrid> image_grid_;
73
74  // Bounds of the content that the shadow encloses.
75  gfx::Rect content_bounds_;
76
77  // The interior inset of the shadow images. The content bounds of the image
78  // grid should be set to |content_bounds_| inset by this amount.
79  int interior_inset_;
80
81  DISALLOW_COPY_AND_ASSIGN(Shadow);
82};
83
84}  // namespace wm
85
86#endif  // UI_WM_CORE_SHADOW_H_
87