// Copyright (C) 2021 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause #include #include // This example show how calling QDialog::exec() shows the dialog, // but does not return. class ClickWindow: public QRasterWindow { public: ClickWindow() { qDebug() << "ClickWindow constructor"; } ~ClickWindow() { qDebug() << "ClickWindow destructor"; } void paintEvent(QPaintEvent *ev) override { QPainter p(this); p.fillRect(ev->rect(), QColorConstants::Svg::deepskyblue); p.drawText(50, 100, "Application has started. See the developer tools console for debug output"); } void mousePressEvent(QMouseEvent *) override { qDebug() << "mousePressEvent(): calling QMessageBox::exec()"; QMessageBox messageBox; messageBox.setText("Hello! This is a message box."); connect(&messageBox, &QMessageBox::buttonClicked, [](QAbstractButton *button) { qDebug() << "Button Clicked" << button; }); messageBox.exec(); // <-- does not return qDebug() << "mousePressEvent(): done"; // <--- will not be printed } }; int main(int argc, char **argv) { QApplication app(argc, argv); ClickWindow window; window.show(); return app.exec(); }