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
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation 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.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <qapplication.h>
#include <qlabel.h>
#include <qpixmap.h>
#include <qprinter.h>
#include <qpainter.h>
#include <qfile.h>
#include <qdir.h>
#include <qfileinfo.h>
#include <QtGui>
#include <QtCore>
class MyClass : public QWidget
{
public:
MyClass(QWidget *parent = 0) : QWidget(parent) { }
protected:
void paintEvent(QPaintEvent *e)
{
/*QRadialGradient rg(50, 50, 50, 50, 50);
rg.setColorAt(0, QColor::fromRgbF(1, 0, 0, 1));
rg.setColorAt(1, QColor::fromRgbF(0, 0, 0, 0));
QPainter pmp(&pm);
pmp.fillRect(0, 0, 100, 100, rg);
pmp.end();*/
createImage();
QPainter p(this);
p.fillRect(rect(), Qt::white);
p.drawPixmap(0, 0, pixmap);
p.drawPixmap(100, 0, channelImage);
}
void createImage()
{
//! [0]
pixmap = QPixmap(100, 100);
pixmap.fill(Qt::transparent);
QRadialGradient gradient(50, 50, 50, 50, 50);
gradient.setColorAt(0, QColor::fromRgbF(1, 0, 0, 1));
gradient.setColorAt(1, QColor::fromRgbF(0, 0, 0, 0));
QPainter painter(&pixmap);
painter.fillRect(0, 0, 100, 100, gradient);
channelImage = pixmap.alphaChannel();
update();
//! [0]
}
QPixmap channelImage, pixmap;
QSize sizeHint() const { return QSize(500, 500); }
};
int main(int argc, char **argv)
{
QApplication app(argc, argv);
MyClass cl;
cl.show();
QObject::connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit()));
int ret = app.exec();
return ret;
}
|
