class Ellipse : public QWidget
{
    Q_OBJECT

public:

    Ellipse(QWidget *parent = 0);
    ~Ellipse();

protected:
    void paintEvent(QPaintEvent *event);
};

Ellipse::Ellipse(QWidget *parent) : QWidget(parent)
{

}

Ellipse::~Ellipse()
{

}

void Ellipse::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);

    QPainter painter(this);

    painter.setPen(QPen(Qt::black, 2, Qt::SolidLine, Qt::FlatCap));
    painter.setBrush(QBrush(Qt::white, Qt::SolidPattern));
    painter.drawEllipse(100, 50, 200, 200);

    painter.drawEllipse(140, 110, 40, 40);
    painter.drawEllipse(220, 110, 40, 40);

    painter.setBrush(QBrush(Qt::black, Qt::SolidPattern));
    painter.drawEllipse(155, 125, 10, 10);
    painter.drawEllipse(235, 125, 10, 10);

    painter.setBrush(QBrush(Qt::white, Qt::SolidPattern));
    painter.drawEllipse(150, 200, 100, 5);
}

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    setWindowTitle("Face");
    setFixedSize(400,400);
    Ellipse *p = new Ellipse;
    connect(ui->pushButton,SIGNAL(clicked()),p,SLOT(repaint()));
}

    ui->setupUi(this);
    scene = new MyScene(this);
....
ui->graphicsView->setScene(scene);

scene->addItem(p);

....
scene->update();
ui->graphicsView->update();