Warning, file /frameworks/kwindowsystem/tests/setmainwindowtest.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*
     This file is part of the KDE libraries
     SPDX-FileCopyrightText: 2013 Aurélien Gâteau <agateau@kde.org>
 
     SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
 #include <kwindowsystem.h>
 
 #include <QApplication>
 #include <QDialog>
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QPushButton>
 
 #include "kx11extras.h"
 
 class Window : public QWidget
 {
 public:
     Window();
 
 private:
     void showWindow();
     QLabel *m_label;
 };
 
 Window::Window()
 {
     QPushButton *button = new QPushButton("Start Test");
     connect(button, &QPushButton::clicked, this, &Window::showWindow);
 
     m_label = new QLabel;
     m_label->setWordWrap(true);
 
     QVBoxLayout *layout = new QVBoxLayout(this);
     layout->addWidget(button);
     layout->addWidget(m_label);
 
     setMinimumSize(200, 150);
 }
 
 void Window::showWindow()
 {
     // Wait for user to select another window
     m_label->setText("Click on another window to show a dialog on it");
     WId us = winId();
     while (KX11Extras::activeWindow() == us) {
         QApplication::processEvents();
     }
 
     // Get the id of the selected window
     WId id = KX11Extras::activeWindow();
     m_label->setText(QString("Showing dialog on window with id: %1.").arg(id));
 
     // Create test dialog
     QDialog *dialog = new QDialog;
     dialog->setAttribute(Qt::WA_DeleteOnClose, true);
     QHBoxLayout *layout = new QHBoxLayout(dialog);
     layout->addWidget(new QLabel("Test Dialog.\nYou should not be able to bring the parent window on top of me."));
 
     // Show it
     dialog->setAttribute(Qt::WA_NativeWindow, true);
     KWindowSystem::setMainWindow(dialog->windowHandle(), id);
     dialog->exec();
 
     m_label->setText(QString());
 }
 
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
     Window window;
     window.show();
     return app.exec();
 }