#include <QApplication>
#include <QMainWindow>
#include <QtDebug>
#include <QTimer>

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

    QMainWindow window;
    window.setWindowState(Qt::WindowMaximized | Qt::WindowMinimized);
    qDebug() << "window state after setting it: " <<  window.windowState();
    window.setVisible(true);
//    QTimer::singleShot(200, [&] { window.setWindowState(window.windowState() | Qt::WindowMaximized | Qt::WindowMinimized); });

    QTimer timer;
    QObject::connect(&timer, &QTimer::timeout, [&window] {
        qDebug() << "window state: " <<  window.windowState();
    });
    timer.setInterval(2000);
    timer.start();
    app.exec();
}