border.h revision 5d1f7b1de12d16ceb2c938c56701a3e8bfa558f7
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_VIEWS_BORDER_H_
6#define UI_VIEWS_BORDER_H_
7
8#include "base/basictypes.h"
9#include "base/memory/scoped_ptr.h"
10#include "third_party/skia/include/core/SkColor.h"
11#include "ui/gfx/insets.h"
12#include "ui/views/views_export.h"
13
14namespace gfx{
15class Canvas;
16class Size;
17}
18
19namespace views {
20
21class Painter;
22class View;
23
24////////////////////////////////////////////////////////////////////////////////
25//
26// Border class.
27//
28// The border class is used to display a border around a view.
29// To set a border on a view, just call SetBorder on the view, for example:
30// view->SetBorder(Border::CreateSolidBorder(1, SkColorSetRGB(25, 25, 112));
31// Once set on a view, the border is owned by the view.
32//
33// IMPORTANT NOTE: not all views support borders at this point. In order to
34// support the border, views should make sure to use bounds excluding the
35// border (by calling View::GetLocalBoundsExcludingBorder) when doing layout and
36// painting.
37//
38////////////////////////////////////////////////////////////////////////////////
39
40class VIEWS_EXPORT Border {
41 public:
42  Border();
43  virtual ~Border();
44
45  // Convenience for creating a scoped_ptr with no Border.
46  static scoped_ptr<Border> NullBorder();
47
48  // Creates a border that is a simple line of the specified thickness and
49  // color.
50  static scoped_ptr<Border> CreateSolidBorder(int thickness, SkColor color);
51
52  // Creates a border for reserving space. The returned border does not
53  // paint anything.
54  static scoped_ptr<Border> CreateEmptyBorder(int top,
55                                              int left,
56                                              int bottom,
57                                              int right);
58
59  // Creates a border of the specified color, and specified thickness on each
60  // side.
61  static scoped_ptr<Border> CreateSolidSidedBorder(int top,
62                                                   int left,
63                                                   int bottom,
64                                                   int right,
65                                                   SkColor color);
66
67  // Creates a Border from the specified Painter. The border owns the painter,
68  // thus the painter is deleted when the Border is deleted.
69  // |insets| define size of an area allocated for a Border.
70  static scoped_ptr<Border> CreateBorderPainter(Painter* painter,
71                                                const gfx::Insets& insets);
72
73  // Renders the border for the specified view.
74  virtual void Paint(const View& view, gfx::Canvas* canvas) = 0;
75
76  // Returns the border insets.
77  virtual gfx::Insets GetInsets() const = 0;
78
79  // Returns the minimum size this border requires.  Note that this may not be
80  // the same as the insets.  For example, a Border may paint images to draw
81  // some graphical border around a view, and this would return the minimum size
82  // such that these images would not be clipped or overlapping -- but the
83  // insets may be larger or smaller, depending on how the view wanted its
84  // content laid out relative to these images.
85  virtual gfx::Size GetMinimumSize() const = 0;
86
87 private:
88  DISALLOW_COPY_AND_ASSIGN(Border);
89};
90
91}  // namespace views
92
93#endif  // UI_VIEWS_BORDER_H_
94