def _updown(self, direction):
if direction == "<STR_LIT>" and self.top_line != <NUM_LIT:0>:<EOL><INDENT>self.top_line -= <NUM_LIT:1><EOL><DEDENT>elif direction == "<STR_LIT>" andself.screen.getmaxyx()[<NUM_LIT:0>] + self.top_line<= self.content_lines + <NUM_LIT:3>:<EOL><INDENT>self.top_line += <NUM_LIT:1><EOL><DEDENT>
Provides curses scroll functionality.