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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include <QApplication>
#include <QtMath>
#include <QPainter>
#include <QVBoxLayout>
#include <QWidget>
class SimpleTransformation : public QWidget
{
void paintEvent(QPaintEvent *) override;
};
//! [0]
void SimpleTransformation::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
painter.drawRect(0, 0, 100, 100);
painter.rotate(45);
painter.setFont(QFont("Helvetica", 24));
painter.setPen(QPen(Qt::black, 1));
painter.drawText(20, 10, "QTransform");
}
//! [0]
class CombinedTransformation : public QWidget
{
void paintEvent(QPaintEvent *) override;
};
//! [1]
void CombinedTransformation::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
painter.drawRect(0, 0, 100, 100);
QTransform transform;
transform.translate(50, 50);
transform.rotate(45);
transform.scale(0.5, 1.0);
painter.setTransform(transform);
painter.setFont(QFont("Helvetica", 24));
painter.setPen(QPen(Qt::black, 1));
painter.drawText(20, 10, "QTransform");
}
//! [1]
class BasicOperations : public QWidget
{
void paintEvent(QPaintEvent *) override;
};
//! [2]
void BasicOperations::paintEvent(QPaintEvent *)
{
const double a = qDegreesToRadians(45.0);
double sina = sin(a);
double cosa = cos(a);
QTransform scale(0.5, 0, 0, 1.0, 0, 0);
QTransform rotate(cosa, sina, -sina, cosa, 0, 0);
QTransform translate(1, 0, 0, 1, 50.0, 50.0);
QTransform transform = scale * rotate * translate;
QPainter painter(this);
painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
painter.drawRect(0, 0, 100, 100);
painter.setTransform(transform);
painter.setFont(QFont("Helvetica", 24));
painter.setPen(QPen(Qt::black, 1));
painter.drawText(20, 10, "QTransform");
}
//! [2]
int main(int argc, char **argv)
{
QApplication app(argc, argv);
QWidget widget;
SimpleTransformation *simpleWidget = new SimpleTransformation;
CombinedTransformation *combinedWidget = new CombinedTransformation;
BasicOperations *basicWidget = new BasicOperations;
QVBoxLayout *layout = new QVBoxLayout;
layout->addWidget(simpleWidget);
layout->addWidget(combinedWidget);
layout->addWidget(basicWidget);
widget.setLayout(layout);
widget.show();
widget.resize(130, 350);
return app.exec();
}
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