1// Copyright (c) 2010 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 CHROME_BROWSER_UI_VIEWS_BUBBLE_BORDER_H_
6#define CHROME_BROWSER_UI_VIEWS_BUBBLE_BORDER_H_
7#pragma once
8
9#include "third_party/skia/include/core/SkColor.h"
10#include "views/background.h"
11#include "views/border.h"
12
13class SkBitmap;
14
15// Renders a border, with optional arrow, and a custom dropshadow.
16// This can be used to produce floating "bubble" objects with rounded corners.
17class BubbleBorder : public views::Border {
18 public:
19  // Possible locations for the (optional) arrow.
20  // 0 bit specifies left or right.
21  // 1 bit specifies top or bottom.
22  // 2 bit specifies horizontal or vertical.
23  enum ArrowLocation {
24    TOP_LEFT     = 0,
25    TOP_RIGHT    = 1,
26    BOTTOM_LEFT  = 2,
27    BOTTOM_RIGHT = 3,
28    LEFT_TOP     = 4,
29    RIGHT_TOP    = 5,
30    LEFT_BOTTOM  = 6,
31    RIGHT_BOTTOM = 7,
32    NONE  = 8,  // No arrow. Positioned under the supplied rect.
33    FLOAT = 9   // No arrow. Centered over the supplied rect.
34  };
35
36  explicit BubbleBorder(ArrowLocation arrow_location)
37      : override_arrow_offset_(0),
38        arrow_location_(arrow_location),
39        background_color_(SK_ColorWHITE) {
40    InitClass();
41  }
42
43  // Returns the radius of the corner of the border.
44  static int GetCornerRadius() {
45    // We can't safely calculate a border radius by comparing the sizes of the
46    // side and corner images, because either may have been extended in various
47    // directions in order to do more subtle dropshadow fading or other effects.
48    // So we hardcode the most accurate value.
49    return 4;
50  }
51
52  // Sets the location for the arrow.
53  void set_arrow_location(ArrowLocation arrow_location) {
54    arrow_location_ = arrow_location;
55  }
56  ArrowLocation arrow_location() const { return arrow_location_; }
57
58  static ArrowLocation horizontal_mirror(ArrowLocation loc) {
59    return loc >= NONE ? loc : static_cast<ArrowLocation>(loc ^ 1);
60  }
61
62  static ArrowLocation vertical_mirror(ArrowLocation loc) {
63    return loc >= NONE ? loc : static_cast<ArrowLocation>(loc ^ 2);
64  }
65
66  static bool has_arrow(ArrowLocation loc) {
67    return loc >= NONE ? false : true;
68  }
69
70  static bool is_arrow_on_left(ArrowLocation loc) {
71    return loc >= NONE ? false : !(loc & 1);
72  }
73
74  static bool is_arrow_on_top(ArrowLocation loc) {
75    return loc >= NONE ? false : !(loc & 2);
76  }
77
78  static bool is_arrow_on_horizontal(ArrowLocation loc) {
79    return loc >= NONE ? false : !(loc & 4);
80  }
81
82  // Sets the background color for the arrow body.  This is irrelevant if you do
83  // not also set the arrow location to something other than NONE.
84  void set_background_color(SkColor background_color) {
85    background_color_ = background_color;
86  }
87  SkColor background_color() const { return background_color_; }
88
89  // For borders with an arrow, gives the desired bounds (in screen coordinates)
90  // given the rect to point to and the size of the contained contents.  This
91  // depends on the arrow location, so if you change that, you should call this
92  // again to find out the new coordinates.
93  gfx::Rect GetBounds(const gfx::Rect& position_relative_to,
94                      const gfx::Size& contents_size) const;
95
96  // Sets a fixed offset for the arrow from the beginning of corresponding edge.
97  // The arrow will still point to the same location but the bubble will shift
98  // location to make that happen. Returns actuall arrow offset, in case of
99  // overflow it differ from desired.
100  int SetArrowOffset(int offset, const gfx::Size& contents_size);
101
102  // Overridden from views::Border:
103  virtual void GetInsets(gfx::Insets* insets) const;
104
105 private:
106  // Loads images if necessary.
107  static void InitClass();
108
109  virtual ~BubbleBorder() { }
110
111  // Overridden from views::Border:
112  virtual void Paint(const views::View& view, gfx::Canvas* canvas) const;
113
114  void DrawEdgeWithArrow(gfx::Canvas* canvas,
115                         bool is_horizontal,
116                         SkBitmap* edge,
117                         SkBitmap* arrow,
118                         int start_x,
119                         int start_y,
120                         int before_arrow,
121                         int after_arrow,
122                         int offset) const;
123
124  void DrawArrowInterior(gfx::Canvas* canvas,
125                         bool is_horizontal,
126                         int tip_x,
127                         int tip_y,
128                         int shift_x,
129                         int shift_y) const;
130
131  // Border graphics.
132  static SkBitmap* left_;
133  static SkBitmap* top_left_;
134  static SkBitmap* top_;
135  static SkBitmap* top_right_;
136  static SkBitmap* right_;
137  static SkBitmap* bottom_right_;
138  static SkBitmap* bottom_;
139  static SkBitmap* bottom_left_;
140  static SkBitmap* left_arrow_;
141  static SkBitmap* top_arrow_;
142  static SkBitmap* right_arrow_;
143  static SkBitmap* bottom_arrow_;
144
145  // Minimal offset of the arrow from the closet edge of bounding rect.
146  static int arrow_offset_;
147
148  // If specified, overrides the pre-calculated |arrow_offset_| of the arrow.
149  int override_arrow_offset_;
150
151  ArrowLocation arrow_location_;
152  SkColor background_color_;
153
154  DISALLOW_COPY_AND_ASSIGN(BubbleBorder);
155};
156
157// A Background that clips itself to the specified BubbleBorder and uses
158// the background color of the BubbleBorder.
159class BubbleBackground : public views::Background {
160 public:
161  explicit BubbleBackground(BubbleBorder* border) : border_(border) {}
162
163  // Background overrides.
164  virtual void Paint(gfx::Canvas* canvas, views::View* view) const;
165
166 private:
167  BubbleBorder* border_;
168
169  DISALLOW_COPY_AND_ASSIGN(BubbleBackground);
170};
171
172#endif  // CHROME_BROWSER_UI_VIEWS_BUBBLE_BORDER_H_
173