1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
|
/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef CONTEXT2D_H
#define CONTEXT2D_H
#include "domimage.h"
#include <QPainter>
#include <QPainterPath>
#include <QString>
#include <QStack>
#include <QMetaType>
#include <QTimerEvent>
// [3]
class CanvasGradient
{
public:
CanvasGradient(const QGradient &v)
: value(v) {}
CanvasGradient() {}
QGradient value;
};
// [3]
Q_DECLARE_METATYPE(CanvasGradient)
Q_DECLARE_METATYPE(CanvasGradient*)
class ImageData {
};
class QContext2DCanvas;
//! [0]
class Context2D : public QObject
{
Q_OBJECT
// compositing
Q_PROPERTY(qreal globalAlpha READ globalAlpha WRITE setGlobalAlpha)
Q_PROPERTY(QString globalCompositeOperation READ globalCompositeOperation WRITE setGlobalCompositeOperation)
Q_PROPERTY(QVariant strokeStyle READ strokeStyle WRITE setStrokeStyle)
Q_PROPERTY(QVariant fillStyle READ fillStyle WRITE setFillStyle)
// line caps/joins
Q_PROPERTY(qreal lineWidth READ lineWidth WRITE setLineWidth)
Q_PROPERTY(QString lineCap READ lineCap WRITE setLineCap)
Q_PROPERTY(QString lineJoin READ lineJoin WRITE setLineJoin)
Q_PROPERTY(qreal miterLimit READ miterLimit WRITE setMiterLimit)
// shadows
Q_PROPERTY(qreal shadowOffsetX READ shadowOffsetX WRITE setShadowOffsetX)
Q_PROPERTY(qreal shadowOffsetY READ shadowOffsetY WRITE setShadowOffsetY)
Q_PROPERTY(qreal shadowBlur READ shadowBlur WRITE setShadowBlur)
Q_PROPERTY(QString shadowColor READ shadowColor WRITE setShadowColor)
//! [0]
public:
Context2D(QObject *parent = 0);
void setSize(int width, int height);
void setSize(const QSize &size);
QSize size() const;
void clear();
void reset();
// compositing
qreal globalAlpha() const; // (default 1.0)
QString globalCompositeOperation() const; // (default over)
QVariant strokeStyle() const; // (default black)
QVariant fillStyle() const; // (default black)
void setGlobalAlpha(qreal alpha);
void setGlobalCompositeOperation(const QString &op);
void setStrokeStyle(const QVariant &style);
void setFillStyle(const QVariant &style);
// line caps/joins
qreal lineWidth() const; // (default 1)
QString lineCap() const; // "butt", "round", "square" (default "butt")
QString lineJoin() const; // "round", "bevel", "miter" (default "miter")
qreal miterLimit() const; // (default 10)
void setLineWidth(qreal w);
void setLineCap(const QString &s);
void setLineJoin(const QString &s);
void setMiterLimit(qreal m);
// shadows
qreal shadowOffsetX() const; // (default 0)
qreal shadowOffsetY() const; // (default 0)
qreal shadowBlur() const; // (default 0)
QString shadowColor() const; // (default black)
void setShadowOffsetX(qreal x);
void setShadowOffsetY(qreal y);
void setShadowBlur(qreal b);
void setShadowColor(const QString &str);
//! [1]
public slots:
void save(); // push state on state stack
void restore(); // pop state stack and restore state
void scale(qreal x, qreal y);
void rotate(qreal angle);
void translate(qreal x, qreal y);
void transform(qreal m11, qreal m12, qreal m21, qreal m22,
qreal dx, qreal dy);
void setTransform(qreal m11, qreal m12, qreal m21, qreal m22,
qreal dx, qreal dy);
CanvasGradient createLinearGradient(qreal x0, qreal y0,
qreal x1, qreal y1);
CanvasGradient createRadialGradient(qreal x0, qreal y0,
qreal r0, qreal x1,
qreal y1, qreal r1);
// rects
void clearRect(qreal x, qreal y, qreal w, qreal h);
void fillRect(qreal x, qreal y, qreal w, qreal h);
void strokeRect(qreal x, qreal y, qreal w, qreal h);
// path API
void beginPath();
void closePath();
void moveTo(qreal x, qreal y);
void lineTo(qreal x, qreal y);
void quadraticCurveTo(qreal cpx, qreal cpy, qreal x, qreal y);
void bezierCurveTo(qreal cp1x, qreal cp1y,
qreal cp2x, qreal cp2y, qreal x, qreal y);
void arcTo(qreal x1, qreal y1, qreal x2, qreal y2, qreal radius);
void rect(qreal x, qreal y, qreal w, qreal h);
void arc(qreal x, qreal y, qreal radius,
qreal startAngle, qreal endAngle,
bool anticlockwise);
void fill();
void stroke();
void clip();
bool isPointInPath(qreal x, qreal y) const;
//! [1]
// drawing images
void drawImage(DomImage *image, qreal dx, qreal dy);
void drawImage(DomImage *image, qreal dx, qreal dy,
qreal dw, qreal dh);
void drawImage(DomImage *image, qreal sx, qreal sy,
qreal sw, qreal sh, qreal dx, qreal dy,
qreal dw, qreal dh);
// pixel manipulation
ImageData getImageData(qreal sx, qreal sy, qreal sw, qreal sh);
void putImageData(ImageData image, qreal dx, qreal dy);
//! [2]
signals:
void changed(const QImage &image);
//! [2]
protected:
void timerEvent(QTimerEvent *e);
private:
void beginPainting();
const QImage &endPainting();
void scheduleChange();
int m_changeTimerId;
QImage m_image;
QPainter m_painter;
QPainterPath m_path;
enum DirtyFlag {
DirtyTransformationMatrix = 0x00001,
DirtyClippingRegion = 0x00002,
DirtyStrokeStyle = 0x00004,
DirtyFillStyle = 0x00008,
DirtyGlobalAlpha = 0x00010,
DirtyLineWidth = 0x00020,
DirtyLineCap = 0x00040,
DirtyLineJoin = 0x00080,
DirtyMiterLimit = 0x00100,
MDirtyPen = DirtyStrokeStyle
| DirtyLineWidth
| DirtyLineCap
| DirtyLineJoin
| DirtyMiterLimit,
DirtyShadowOffsetX = 0x00200,
DirtyShadowOffsetY = 0x00400,
DirtyShadowBlur = 0x00800,
DirtyShadowColor = 0x01000,
DirtyGlobalCompositeOperation = 0x2000,
DirtyFont = 0x04000,
DirtyTextAlign = 0x08000,
DirtyTextBaseline = 0x10000,
AllIsFullOfDirt = 0xfffff
};
struct State {
State() : flags(0) {}
QMatrix matrix;
QPainterPath clipPath;
QBrush strokeStyle;
QBrush fillStyle;
qreal globalAlpha;
qreal lineWidth;
Qt::PenCapStyle lineCap;
Qt::PenJoinStyle lineJoin;
qreal miterLimit;
qreal shadowOffsetX;
qreal shadowOffsetY;
qreal shadowBlur;
QColor shadowColor;
QPainter::CompositionMode globalCompositeOperation;
QFont font;
int textAlign;
int textBaseline;
int flags;
};
State m_state;
QStack<State> m_stateStack;
};
#endif
|
