Can't catch DragLeaveEvent

[high_flyer]

You are not checking for the obj receiving the event.
This should not be a problem, but see if you get at all events from your list:

bool MyDialog::eventFilter(QObject *obj, QEvent *event)
{
    qDebug() << "Event Filter called with " << event->type();
    if(obj == ui->myList)
   {
       if (event->type() == QEvent::DragLeave) {
        qDebug() << event->type() << "= drag leave event.";
        return true;
        } else if (event->type() == QEvent::DragEnter) {
        qDebug() << event->type() << "= drag enter event.";
        return true;
       } 
   }
   else {
        // standard event processing
        return QObject::eventFilter(obj, event);
    }
}

bool MyDialog::eventFilter(QObject *obj, QEvent *event)
{
    qDebug() << "Event Filter called with " << event->type();
    if(obj == ui->myList)
   {
       if (event->type() == QEvent::DragLeave) {
        qDebug() << event->type() << "= drag leave event.";
        return true;
        } else if (event->type() == QEvent::DragEnter) {
        qDebug() << event->type() << "= drag enter event.";
        return true;
       } 
   }
   else {
        // standard event processing
        return QObject::eventFilter(obj, event);
    }
}

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[steps]

Hi, I changed my code the way you suggested, but I don't see that it changed much with regard to the output I get. Specifically, I still don't get the dragLeaveEvent. I get the regular Enter and Leave events fine (10 and 11 respectively, see here), but not the dragEnter and dragLeave events (60 and 62).

[high_flyer]

The idea was to see if you are getting ANY events from this object.
Put a debug output before the first if(event()->type()...) statement and see if it gets printed out.

[steps]

Sorry, I was being unprecise. I changed my code to the following:

bool MyDialog::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == ui->myList) {
        qDebug() << "Event Filter called with " << event->type();
        if (event->type() == QEvent::DragLeave) {
            qDebug() << event->type() << "= drag leave event.";
            return true;
        } else if (event->type() == QEvent::DragEnter) {
            qDebug() << event->type() << "= drag enter event.";
            return true;
        } else if (event->type() == QEvent::Drop) {
            qDebug() << event->type() << "= drop event.";
            return true;
        }
    } else {
        // standard event processing
        return QObject::eventFilter(obj, event);
    }
}

bool MyDialog::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == ui->myList) {
        qDebug() << "Event Filter called with " << event->type();
        if (event->type() == QEvent::DragLeave) {
            qDebug() << event->type() << "= drag leave event.";
            return true;
        } else if (event->type() == QEvent::DragEnter) {
            qDebug() << event->type() << "= drag enter event.";
            return true;
        } else if (event->type() == QEvent::Drop) {
            qDebug() << event->type() << "= drop event.";
            return true;
        }
    } else {
        // standard event processing
        return QObject::eventFilter(obj, event);
    }
}

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Result was as described above.

[Spitfire]

Two things:

1) List must have DragDropMode set to DragDrop or InternalMove, otherwise drag Enter/Leave events will not be delivered (don't ask why).
2) For another reason I don't know you can't reliably intercept drag enter/leave events using event filter. Subclass QListWidget and reimplement dragEnterEvent() and dragLeaveEvent().

class MyList : public QListWidget
{
public:
    MyList( QWidget* parent = 0 ) : QListWidget( parent ) {}
 
    void    dragEnterEvent( QDragEnterEvent* e )
    {
        qDebug() << "Enter!";
        QListWidget::dragEnterEvent( e );
    }
 
    void    dragLeaveEvent( QDragLeaveEvent* e )
    {
        qDebug() << "Leave!";
        QListWidget::dragLeaveEvent( e );
    }
};

class MyList : public QListWidget
{
public:
    MyList( QWidget* parent = 0 ) : QListWidget( parent ) {}

    void    dragEnterEvent( QDragEnterEvent* e )
    {
        qDebug() << "Enter!";
        QListWidget::dragEnterEvent( e );
    }

    void    dragLeaveEvent( QDragLeaveEvent* e )
    {
        qDebug() << "Leave!";
        QListWidget::dragLeaveEvent( e );
    }
};

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Maybe threre are some flags that could alter this behavious but I don't know them.

[steps]

Yeah, I haven't found any way around subclassing either, that's why I posted here. Thanks for your help everyone!