def METHOD_NAME(self):
    """Read another line from the file."""
    next_line = self.file.readline()
    if not next_line or next_line[-1:] != '\n':
        # no newline on last line of file
        self.file = None
    else:
        # trim newline characters
        next_line = next_line[:-1]
    expanded = next_line.expandtabs()
    edit = urwid.Edit("", expanded, allow_tab=True)
    edit.set_edit_pos(0)
    edit.original_text = next_line
    self.lines.append(edit)
    return next_line