i only created the animated intro and now i want to go to the main menu when the animated intro ends.

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    //Background
    ui->setupUi(this);
    QPixmap bkgnd(":/rec/Images/backgorund.png");
    bkgnd = bkgnd.scaled(this->size(), Qt::IgnoreAspectRatio);
    QPalette palette;
    palette.setBrush(QPalette::Window, bkgnd);
    this->setPalette(palette);

    //Logo
    QPixmap iti(":/rec/Images/logo.png");
    QLabel *label = new QLabel(this);
    label->setPixmap(iti);
    QHBoxLayout *layout = new QHBoxLayout(this);
    layout->addWidget(label);
    layout->setAlignment(Qt::AlignCenter);
    QWidget *centralWidget = new QWidget(this);
    centralWidget->setLayout(layout);
    setCentralWidget(centralWidget);

    //Fade in effect
    QGraphicsOpacityEffect *eff = new QGraphicsOpacityEffect(this);
    label->setGraphicsEffect(eff);
    QPropertyAnimation *a = new QPropertyAnimation(eff,"opacity");
    a->setDuration(4000);
    a->setStartValue(0);
    a->setEndValue(1);
    a->setEasingCurve(QEasingCurve::InBack);
    a->start(QPropertyAnimation::DeleteWhenStopped);
}