Listens for query's being dragged and dropped onto this tree.
        
        :param      event | <QDragEnterEvent>

def dragEnterEvent(self, event):
        """
        Listens for query's being dragged and dropped onto this tree.
        
        :param      event | <QDragEnterEvent>
        """
        data = event.mimeData()
        if data.hasFormat('application/x-orb-table') and \
           data.hasFormat('application/x-orb-query'):
            tableName = self.tableTypeName()
            if nativestring(data.data('application/x-orb-table')) == tableName:
                event.acceptProposedAction()
                return
        
        super(XOrbTreeWidget, self).dragEnterEvent(event)