CODEWITHSUNDEEP
qtlistviewsignals-slotsqabstractitemmodel
David Menard
David Menard

Reputation: 2321

QObject::connect issues with QAbstractItemModel

I have a QListView from which I obtain a QAbstractItemModel with list->model();

After this, I want to connect the dataChanged signal to a custom QObject of mine:

 if( QObject::connect(model, SIGNAL(dataChanged (const QModelIndex , const QModelIndex ) ),
                        customObject_,SLOT(onText(const QModelIndex , const QModelIndex )) ) )
     cout << "SIGNAL SLOT connection successful" << endl;
 else
     cout << "SIGNAL SLOT connection ERROR" << endl;

here is my custom object:

 class CustomObject : public QObject
{
    Q_OBJECT

public:
    CustomObject (QObject *parent);
    ~CustomObject ();

public slots:
    void onText(const QModelIndex & topLeft, const QModelIndex & bottomRight );

private:

};

Am I doing anything wrong? The QObject call returns true, I have a cout in the onText function, but nothing is ever printed when the QListView is Changed.

Upvotes: 2

Views: 2695

Answers (3)

ufukgun
ufukgun

Reputation: 7209

maybe there is & in your function..

but if it was the problem, it should display an error by your function...

probably this signal is not emmited. Try to connect with another signal.. you can test it like that..

Upvotes: 0

Marc Mutz - mmutz
Marc Mutz - mmutz

Reputation: 25293

That probably means that the signal is never emitted. Try calling

model->setData( model->index( 0, 0 ), Qt::EditRole, 3.14 );

If that one doesn't invoke your slot, then the implementation of setData() is probably buggy and doesn't emit dataChanged(QModelIndex,QModelIndex), or else customObject_ has since been deleted.

If neither is the case, you need to give us more information.

Upvotes: 4

OneOfOne
OneOfOne

Reputation: 99274

Did you try with 

QObject::connect(model, SIGNAL(dataChanged (const QModelIndex &, const QModelIndex &) ),
                    customObject_,SLOT(onText(const QModelIndex &, const QModelIndex &)) );

? aka make sure the parameters are passed by reference. Check this tutorial.

Upvotes: -1

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