QGraphicsItem inheritence

[bajarangi]

I need to subclass an existing QGraphicsItem and change the painting
and size. I started modifying the elasticnodes example and came up with
these changes:

class Node : public QGraphicsItem
{
public:
    Node(GraphWidget *graphWidget);
 
    void addEdge(Edge *edge);
    QList<Edge *> edges() const;
 
    enum { Type = UserType + 1 };
    int type() const { return Type; }
 
    void calculateForces();
    bool advance();
 
    virtual QRectF boundingRect() const;
    QPainterPath shape() const;
    virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
 
protected:
    QVariant itemChange(GraphicsItemChange change, const QVariant &value);
 
    virtual void mousePressEvent(QGraphicsSceneMouseEvent *event);
    virtual void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);
 
    QList<Edge *> edgeList;
    QPointF newPos;
    GraphWidget *graph;
 
private:
 
};

class Node : public QGraphicsItem
{
public:
    Node(GraphWidget *graphWidget);

    void addEdge(Edge *edge);
    QList<Edge *> edges() const;

    enum { Type = UserType + 1 };
    int type() const { return Type; }

    void calculateForces();
    bool advance();

    virtual QRectF boundingRect() const;
    QPainterPath shape() const;
    virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);

protected:
    QVariant itemChange(GraphicsItemChange change, const QVariant &value);

    virtual void mousePressEvent(QGraphicsSceneMouseEvent *event);
    virtual void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);

    QList<Edge *> edgeList;
    QPointF newPos;
    GraphWidget *graph;
	
private:

};

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So for my derived class, I need to make boundingRect(), paint(), and mousePressEvent() virtual, because I want my class to paint a pixmap
and catch it's own mousePressEvents.
Correct?

So I subclassed Node, loaded a rectangular image in the constructor, implemented boundingRect(), paint(), and mousePressEvent(). Compiles and runs ok.
Just one problem - I can't drag the rectangular image by the mouse!

Some qDebug statements in the relevant methods shows that the derived class
is receiving mousePressEvents, but only in the exact area where a Node (ball) would be (around 0,0 in my pixmap). It looks like I need to make another method in Node virtual to override the default area where a Node accepts mouse events.

I hope this is clear. The attached jpg shows a closeup.
The white circle is some sort of "ghost" node that will accept a mouse press
and allow me to drag the pixmap. I can't drag the pixmap anywhere else.

thanks,
-baj