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_PAINTER_H_
6#define UI_VIEWS_PAINTER_H_
7
8#include "base/basictypes.h"
9#include "base/compiler_specific.h"
10#include "base/memory/scoped_ptr.h"
11#include "third_party/skia/include/core/SkColor.h"
12#include "ui/base/nine_image_painter_factory.h"
13#include "ui/views/views_export.h"
14
15namespace gfx {
16class Canvas;
17class ImageSkia;
18class Insets;
19class Rect;
20class Size;
21}
22
23namespace views {
24
25class View;
26
27// Painter, as the name implies, is responsible for painting in a particular
28// region. Think of Painter as a Border or Background that can be painted
29// in any region of a View.
30class VIEWS_EXPORT Painter {
31 public:
32  Painter();
33  virtual ~Painter();
34
35  // A convenience method for painting a Painter in a particular region.
36  // This translates the canvas to x/y and paints the painter.
37  static void PaintPainterAt(gfx::Canvas* canvas,
38                             Painter* painter,
39                             const gfx::Rect& rect);
40
41  // Convenience that paints |focus_painter| only if |view| HasFocus() and
42  // |focus_painter| is non-NULL.
43  static void PaintFocusPainter(View* view,
44                                gfx::Canvas* canvas,
45                                Painter* focus_painter);
46
47  // Creates a painter that draws a gradient between the two colors.
48  static Painter* CreateHorizontalGradient(SkColor c1, SkColor c2);
49  static Painter* CreateVerticalGradient(SkColor c1, SkColor c2);
50
51  // Creates a painter that draws a multi-color gradient. |colors| contains the
52  // gradient colors and |pos| the relative positions of the colors. The first
53  // element in |pos| must be 0.0 and the last element 1.0. |count| contains
54  // the number of elements in |colors| and |pos|.
55  static Painter* CreateVerticalMultiColorGradient(SkColor* colors,
56                                                   SkScalar* pos,
57                                                   size_t count);
58
59  // Creates a painter that divides |image| into nine regions. The four corners
60  // are rendered at the size specified in insets (eg. the upper-left corner is
61  // rendered at 0 x 0 with a size of insets.left() x insets.top()). The center
62  // and edge images are stretched to fill the painted area.
63  static Painter* CreateImagePainter(const gfx::ImageSkia& image,
64                                     const gfx::Insets& insets);
65
66  // Creates a painter that paints images in a scalable grid. The images must
67  // share widths by column and heights by row. The corners are painted at full
68  // size, while center and edge images are stretched to fill the painted area.
69  // The center image may be zero (to be skipped). This ordering must be used:
70  // Top-Left/Top/Top-Right/Left/[Center]/Right/Bottom-Left/Bottom/Bottom-Right.
71  static Painter* CreateImageGridPainter(const int image_ids[]);
72
73  // Factory methods for creating painters intended for rendering focus.
74  static scoped_ptr<Painter> CreateDashedFocusPainter();
75  static scoped_ptr<Painter> CreateDashedFocusPainterWithInsets(
76      const gfx::Insets& insets);
77  static scoped_ptr<Painter> CreateSolidFocusPainter(SkColor color,
78                                                     const gfx::Insets& insets);
79
80  // Returns the minimum size this painter can paint without obvious graphical
81  // problems (e.g. overlapping images).
82  virtual gfx::Size GetMinimumSize() const = 0;
83
84  // Paints the painter in the specified region.
85  virtual void Paint(gfx::Canvas* canvas, const gfx::Size& size) = 0;
86
87 private:
88  DISALLOW_COPY_AND_ASSIGN(Painter);
89};
90
91// HorizontalPainter paints 3 images into a box: left, center and right. The
92// left and right images are drawn to size at the left/right edges of the
93// region. The center is tiled in the remaining space. All images must have the
94// same height.
95class VIEWS_EXPORT HorizontalPainter : public Painter {
96 public:
97  // Constructs a new HorizontalPainter loading the specified image names.
98  // The images must be in the order left, right and center.
99  explicit HorizontalPainter(const int image_resource_names[]);
100  virtual ~HorizontalPainter();
101
102  // Painter:
103  virtual gfx::Size GetMinimumSize() const OVERRIDE;
104  virtual void Paint(gfx::Canvas* canvas, const gfx::Size& size) OVERRIDE;
105
106 private:
107  // The image chunks.
108  enum BorderElements {
109    LEFT,
110    CENTER,
111    RIGHT
112  };
113
114  // NOTE: the images are owned by ResourceBundle. Don't free them.
115  const gfx::ImageSkia* images_[3];
116
117  DISALLOW_COPY_AND_ASSIGN(HorizontalPainter);
118};
119
120}  // namespace views
121
122#endif  // UI_VIEWS_PAINTER_H_
123