Revision control
++ // Copyright (C) 2024 Christian Ehrlicher <ch.ehrlicher@gmx.de>
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++ #include <QPaintEvent>
++ #include <QPainter>
++ #include <QPainterStateGuard>
++ #include <QWidget>
++
++
++ namespace src_gui_painting_qpainterstateguard {
++ struct MyWidget : public QWidget
++ {
++ void paintEvent(QPaintEvent *) override;
++ bool drawText = true;
++ QLine line;
++ };
++ struct MyGuardWidget : public QWidget
++ {
++ void paintEvent(QPaintEvent *) override;
++ bool drawText = true;
++ QLine line;
++ };
++
++ //! [0]
++ void MyWidget::paintEvent(QPaintEvent *)
++ {
++ QPainter painter(this);
++ painter.setPen(Qt::red);
++ if (drawText) {
++ painter.save();
++ painter.setPen(Qt::blue);
++ painter.setFont(QFont("Arial", 30));
++ painter.drawText(rect(), Qt::AlignCenter, "Qt");
++ painter.restore(); // don't forget to restore previous painter state
++ }
++ painter.drawLine(line);
++ }
++ //! [0]
++
++ //! [1]
++ void MyGuardWidget::paintEvent(QPaintEvent *)
++ {
++ QPainter painter(this);
++ painter.setPen(Qt::red);
++ if (drawText) {
++ QPainterStateGuard guard(&painter);
++ painter.setPen(Qt::blue);
++ painter.setFont(QFont("Arial", 30));
++ painter.drawText(rect(), Qt::AlignCenter, "Qt");
++ }
++ painter.drawLine(line);
++ }
++ //! [1]
++
++ } // src_gui_painting_qpainterstateguard