Items after dropping from widget to widget missing

[Huy Manh]

After dragging and dropping an item from a list widget to a list widget, the item disappears in the target list widget.

I used eventFilter for only the list widgets in MainWindow.

bool MainWindow::eventFilter(QObject *target,QEvent *event){
    if (event->type() == QEvent::DragEnter)
       {
          QDragEnterEvent *tDragEnterEvent = static_cast<QDragEnterEvent *>(event);
          tDragEnterEvent->acceptProposedAction();

          return true;
       }
       else if (event->type() == QEvent::DragMove)
       {
          QDragMoveEvent *tDragMoveEvent = static_cast<QDragMoveEvent *>(event);
          tDragMoveEvent->acceptProposedAction();

          return true;
       }
        else if (event->type() == QEvent::Drop)
       {
          QDropEvent *tDropEvent = static_cast<QDropEvent *>(event);
          tDropEvent->acceptProposedAction();

          qDebug() << "OK, execute your task!";

          return true;
       }
       else
       {
           // standard event processing
           return QObject::eventFilter(target, event);
       }


    //return false;
}
//in MainWindow constructor
ui->listWidget->installEventFilter(this);

qDebug showed the debug string after dropping but the item went missing.

[Christian Ehrlicher]

You filter out the drop events and the wonder why the widget which should receive them don't receive them? Mhh.

[Huy Manh]

Sorry but I don't know your meaning, I've been using Qt for about 3 months and this is the first time I handle events, so I hope you can help me with this minor problem, thank you.

[Christian Ehrlicher]

See documentation for QObject::eventFilter(): "... if you want to filter the event out, i.e. stop it being handled further, return true; ..." which is exactly what you're doing.

[Huy Manh]

Oh, I get it. Can you suggest for me a solution? That is, if I drop an item into the list widget, I have a variable "count" plus 1 and if I drag an item out, "count" minus 1. I thought at first that eventFilter will help me.

[Christian Ehrlicher]

Drag'n'Drop from a QListWidget to another QListWidget should work out-of-the-box if dragEnabled/acceptDrops is active - see documentation