raw_display.py 文件源码

def _start(self, alternate_buffer=True):
        """
        Initialize the screen and input mode.

        alternate_buffer -- use alternate screen buffer
        """
        if alternate_buffer:
            self.write(escape.SWITCH_TO_ALTERNATE_BUFFER)
            self._rows_used = None
        else:
            self._rows_used = 0

        fd = self._term_input_file.fileno()
        if os.isatty(fd):
            self._old_termios_settings = termios.tcgetattr(fd)
            tty.setcbreak(fd)

        self.signal_init()
        self._alternate_buffer = alternate_buffer
        self._next_timeout = self.max_wait

        if not self._signal_keys_set:
            self._old_signal_keys = self.tty_signal_keys(fileno=fd)

        signals.emit_signal(self, INPUT_DESCRIPTORS_CHANGED)
        # restore mouse tracking to previous state
        self._mouse_tracking(self._mouse_tracking_enabled)

        return super(Screen, self)._start()