code: def get_selected_filenames(self):
          
          if self.selectionMode() == self.ExtendedSelection:
              if self.selectionModel() is None:
                  return []
              return [self.get_filename(idx) for idx in 
                      self.selectionModel().selectedRows()]
          else:
              return [self.get_filename(self.currentIndex())]
docs: Return selected filenames