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50
51 #include <QtGui>
52 #include <cmath>
53
54 class SimpleTransformation : public QWidget
55 {
56 void paintEvent(QPaintEvent *) override;
57 };
58
59 //! [0]
paintEvent(QPaintEvent *)60 void SimpleTransformation::paintEvent(QPaintEvent *)
61 {
62 QPainter painter(this);
63 painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
64 painter.drawRect(0, 0, 100, 100);
65
66 painter.rotate(45);
67
68 painter.setFont(QFont("Helvetica", 24));
69 painter.setPen(QPen(Qt::black, 1));
70 painter.drawText(20, 10, "QTransform");
71 }
72 //! [0]
73
74 class CombinedTransformation : public QWidget
75 {
76 void paintEvent(QPaintEvent *) override;
77 };
78
79 //! [1]
paintEvent(QPaintEvent *)80 void CombinedTransformation::paintEvent(QPaintEvent *)
81 {
82 QPainter painter(this);
83 painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
84 painter.drawRect(0, 0, 100, 100);
85
86 QTransform transform;
87 transform.translate(50, 50);
88 transform.rotate(45);
89 transform.scale(0.5, 1.0);
90 painter.setTransform(transform);
91
92 painter.setFont(QFont("Helvetica", 24));
93 painter.setPen(QPen(Qt::black, 1));
94 painter.drawText(20, 10, "QTransform");
95 }
96 //! [1]
97
98 class BasicOperations : public QWidget
99 {
100 void paintEvent(QPaintEvent *) override;
101 };
102
103 //! [2]
paintEvent(QPaintEvent *)104 void BasicOperations::paintEvent(QPaintEvent *)
105 {
106 double pi = 3.14;
107
108 double a = pi/180 * 45.0;
109 double sina = sin(a);
110 double cosa = cos(a);
111
112 QTransform translationTransform(1, 0, 0, 1, 50.0, 50.0);
113 QTransform rotationTransform(cosa, sina, -sina, cosa, 0, 0);
114 QTransform scalingTransform(0.5, 0, 0, 1.0, 0, 0);
115
116 QTransform transform;
117 transform = scalingTransform * rotationTransform * translationTransform;
118
119 QPainter painter(this);
120 painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
121 painter.drawRect(0, 0, 100, 100);
122
123 painter.setTransform(transform);
124
125 painter.setFont(QFont("Helvetica", 24));
126 painter.setPen(QPen(Qt::black, 1));
127 painter.drawText(20, 10, "QTransform");
128 }
129 //! [2]
130
main(int argc,char ** argv)131 int main(int argc, char **argv)
132 {
133 QApplication app(argc, argv);
134
135 QWidget widget;
136
137 SimpleTransformation *simpleWidget = new SimpleTransformation;
138 CombinedTransformation *combinedWidget = new CombinedTransformation;
139 BasicOperations *basicWidget = new BasicOperations;
140
141 QVBoxLayout *layout = new QVBoxLayout;
142 layout->addWidget(simpleWidget);
143 layout->addWidget(combinedWidget);
144 layout->addWidget(basicWidget);
145 widget.setLayout(layout);
146
147 widget.show();
148 widget.resize(130, 350);
149 return app.exec();
150 }
151