#include <QApplication>
#include <QWidget>
#include <QDebug>


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

    for (int i=0; i<4; ++i) {
        QWidget* w = new QWidget();
        w->setWindowTitle(QString("My Widget %1").arg(i));
        w->move(410*i, 32);
        w->resize(400, 300);
        w->show();
    }
    app.processEvents();
    foreach (QWidget* w, qApp->topLevelWidgets()) {
        qDebug() << "Top Level = :[[" <<w <<"]] Visible ? = ["<< w->isVisible();
    }

    return app.exec();
}