Signals and slots for QGraphicsEllipseItem

[Cruz]

Hello!

I would like to add signal and slot capability to a QGraphicsEllipseItem. I read that I should inherit from QObject as well, but it didn't work. This code:

class ComState : public QGraphicsEllipseItem, QObject
{
    Q_OBJECT
 
	double comRadius;
 
public:
    ComState(QGraphicsItem *parent = 0);
    ~ComState(){};
 
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
 
signals:
	void stateChangedOut();
};
 
ComState::ComState(QGraphicsItem *parent)
    : QGraphicsEllipseItem(parent),QObject()
{
	comRadius = 0.05;
 
	setFlags(QGraphicsItem::ItemIsMovable);
	setRect(QRectF(-comRadius, -comRadius, 2.0*comRadius, 2.0*comRadius));
}

class ComState : public QGraphicsEllipseItem, QObject
{
    Q_OBJECT

	double comRadius;

public:
    ComState(QGraphicsItem *parent = 0);
    ~ComState(){};

    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);

signals:
	void stateChangedOut();
};

ComState::ComState(QGraphicsItem *parent)
    : QGraphicsEllipseItem(parent),QObject()
{
	comRadius = 0.05;

	setFlags(QGraphicsItem::ItemIsMovable);
	setRect(QRectF(-comRadius, -comRadius, 2.0*comRadius, 2.0*comRadius));
}

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Produces this compile error:

debug\moc_ComState.cpp:44: error: 'staticMetaObject' is not a member of 'QGraphicsEllipseItem'
debug\moc_ComState.cpp: In member function 'virtual void* ComState::qt_metacast(const char*)':
debug\moc_ComState.cpp:64: error: 'qt_metacast' is not a member of 'QGraphicsEllipseItem'
debug\moc_ComState.cpp: In member function 'virtual int ComState::qt_metacall(QMetaObject::Call, int, void**)':
debug\moc_ComState.cpp:69: error: 'qt_metacall' is not a member of 'QGraphicsEllipseItem'

I would really like to make this work instead of going the QGraphicsObject way, because I'm using things that QGraphicsEllipseItem provides.
What do I do now?

Thanks
Cruz

[^NyAw^]

Hi,

Try changing the order of base classes and also use the "public" keyword as I think that the default interpretation is that it have to inherit as private

class ComState : public QObject, public QGraphicsEllipseItem

class ComState : public QObject, public QGraphicsEllipseItem

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[Cruz]

Yes it worked!

[anda_skoa]

The orignal code also had the problem that the inheritance from QObject was private.

^NyAw^'s suggestion fixed both problems

Cheers,
_