Trouble animating line point

Hi,

I'm trying to use the animation framework to animate a point of a line but I keep getting the error:
QPropertyAnimation: you're trying to animate a non-existing property pt1 of your QObject

Code:

---

class MyLine : public QGraphicsWidget {
Q_PROPERTY(QPoint pt1 READ pt1 WRITE setPt1)
public:
    QPoint pt1;
 
    MyLine() {
        pt1 = *new QPoint(10, 10);
    }
 
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) {
        painter->setPen(Qt::red);
        painter->drawLine(pt1, QPoint(100, 100));
    }
 
    void setPt1(QPoint p) {
        pt1.setX(p.x());
        pt1.setY(p.y());
    }
};
 
// Calling code is:
QPropertyAnimation anim(&r, "pt1");
anim.setDuration(4000);
anim.setStartValue(QPoint(10, 10));
anim.setEndValue(QPoint(100, 100));
anim.start();

---

Can you tell me why am I getting this error? I'm also a c++ newbie so my use of pointers and so might be wrong...

Thanks!