class OxygenWidget : public QWidget
{
protected:
    virtual void paintEvent ( QPaintEvent * event );
};

void OxygenWidget::paintEvent ( QPaintEvent * )
{
    QPainter painter(this);

    QRadialGradient grad1(QPointF(5.0, 5.0),5.0);
    grad1.setColorAt(0.9, QColor(0,0,0,100));
    grad1.setColorAt(1.0, QColor(0,0,0,0));
    QRadialGradient grad2(QPointF(5.0, 5.0),5.0);
    grad2.setColorAt(0.0, QColor(235,235,235));
    grad2.setColorAt(1.0, QColor(220,220,220));
    QRadialGradient grad3(QPointF(5.0, 3.75), 3.5,QPointF(5.0, 2.5));
    grad3.setColorAt(0, QColor(255,255,255,50));
    grad3.setColorAt(1, QColor(255,255,255,0));
    QRadialGradient grad4(QPointF(5.0, 3.3), 3.5, QPointF(5.0, 2.1));
    grad4.setColorAt(0, QColor(255,255,255,50));
    grad4.setColorAt(1, QColor(255,255,255,0));
    QBrush brush1(grad1);
    QBrush brush2(grad2);
    QBrush brush3(grad3);
    QBrush brush4(grad4);

    painter.scale(1.6, 1.6);
    painter.setRenderHint(QPainter::Antialiasing,true);

    QPainterPath path1;
    path1.addEllipse(0.0, 0.0, 10.0, 10.0);
    painter.fillPath(path1, brush1);

    QPainterPath path2;
    path2.addEllipse(0.5, 0.5, 9.0, 9.0);
    painter.fillPath(path2, brush2);

    QPainterPath path3;
    path3.addEllipse(1.5, 0.5, 7.0, 6.0);
    painter.fillPath(path3, brush3);

    QPainterPath path4;
    path4.addEllipse(1.5, 0.5, 7.0, 6.0);
    painter.fillPath(path4, brush4);
}