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

def dropEvent(self, event):
        """
        Listens for query's being dragged and dropped onto this tree.
        
        :param      event | <QDropEvent>
        """
        # overload the current filtering options
        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:
                data = nativestring(data.data('application/x-orb-query'))
                query = Q.fromXmlString(data)
                self.setQuery(query)
                return
        
        super(XOrbTreeWidget, self).dropEvent(event)