GUI/src/main.cpp

#include "mainwindow.h"
#include <QApplication>
#include "loginwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    needLogin:
    LoginWindow l;
    l.showFullScreen();
    MainWindow w;
    int rec =  l.exec();
    if (rec !=QDialog::Accepted )
    {
        goto needLogin;
    }
//    l.deleteLater();

    w.showFullScreen();

    return a.exec();
}