#include "mainwindow.h"
#include <QApplication>
#include <QApplication>
#include <QDialog>
#include <QMessageBox>
#include <QTimer>
#include <QDebug>

class MyDialog : public QDialog
{
public:
    using QDialog::QDialog;

protected:
    bool event(QEvent *e) override
    {
        if (e->type() == QEvent::WindowDeactivate) {
            qDebug() << "received windows deactivate";
            QTimer::singleShot(1000, this, [this] {
                QMessageBox::information(this, "title", "text");
            });
        }

        return QDialog::event(e);
    }
};


int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    MyDialog dialog;
    dialog.open();

    return app.exec();
}


/*int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}*/