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_GFX_SHADOW_VALUE_H_
6#define UI_GFX_SHADOW_VALUE_H_
7
8#include <string>
9#include <vector>
10
11#include "third_party/skia/include/core/SkColor.h"
12#include "ui/gfx/gfx_export.h"
13#include "ui/gfx/point.h"
14
15namespace gfx {
16
17class Insets;
18
19class ShadowValue;
20typedef std::vector<ShadowValue> ShadowValues;
21
22// ShadowValue encapsulates parameters needed to define a shadow, including the
23// shadow's offset, blur amount and color.
24class GFX_EXPORT ShadowValue {
25 public:
26  ShadowValue();
27  ShadowValue(const gfx::Point& offset, double blur, SkColor color);
28  ~ShadowValue();
29
30  int x() const { return offset_.x(); }
31  int y() const { return offset_.y(); }
32  const gfx::Point& offset() const { return offset_; }
33  double blur() const { return blur_; }
34  SkColor color() const { return color_; }
35
36  ShadowValue Scale(float scale) const;
37
38  std::string ToString() const;
39
40  // Gets margin space needed for shadows. Note that values in returned Insets
41  // are negative because shadow margins are outside a boundary.
42  static Insets GetMargin(const ShadowValues& shadows);
43
44 private:
45  gfx::Point offset_;
46
47  // Blur amount of the shadow in pixels. If underlying implementation supports
48  // (e.g. Skia), it can have fraction part such as 0.5 pixel. The value
49  // defines a range from full shadow color at the start point inside the
50  // shadow to fully transparent at the end point outside it. The range is
51  // perpendicular to and centered on the shadow edge. For example, a blur
52  // amount of 4.0 means to have a blurry shadow edge of 4 pixels that
53  // transitions from full shadow color to fully transparent and with 2 pixels
54  // inside the shadow and 2 pixels goes beyond the edge.
55  double blur_;
56
57  SkColor color_;
58};
59
60}  // namespace gfx
61
62#endif  // UI_GFX_SHADOW_VALUE_H_
63