class CustomItem : public QQuickPaintedItem
{
    Q_OBJECT
protected:
    virtual void mousePressEvent(QMouseEvent *ev);
    virtual void paint(QPainter *p);
}

void CustomItem::mousePressEvent(QMouseEvent *ev)
{
    Q_UNUSED(ev);
}

void CustomItem::paint(QPainter *p)
{
    p->drawRect(QRectF(0,0,10,10));
}