keyboard.py 文件源码

def _alternative_left_right(term):
    r"""
    Determine and return mapping of left and right arrow keys sequences.

    :arg blessed.Terminal term: :class:`~.Terminal` instance.
    :rtype: dict

    This function supports :func:`get_terminal_sequences` to discover
    the preferred input sequence for the left and right application keys.

    Return dict of sequences ``term._cuf1``, and ``term._cub1``,
    valued as ``KEY_RIGHT``, ``KEY_LEFT`` (when appropriate).  It is
    necessary to check the value of these sequences to ensure we do not
    use ``u' '`` and ``u'\b'`` for ``KEY_RIGHT`` and ``KEY_LEFT``,
    preferring their true application key sequence, instead.
    """
    keymap = dict()
    if term._cuf1 and term._cuf1 != u' ':
        keymap[term._cuf1] = curses.KEY_RIGHT
    if term._cub1 and term._cub1 != u'\b':
        keymap[term._cub1] = curses.KEY_LEFT
    return keymap