code: def text_filter_changed(self, text):
          
          text = text.strip() if text else None
  
          if text is not None:
              self.__text_filter = ListModel.TextFilter("text_for_filter", text)
          else:
              self.__text_filter = None
  
          self.__update_filter()
docs: Called to handle changes to the text filter.
  
              :param text: The text for the filter.