How to use the stig.tui.keymap.Key function in stig

- A Key or KeyChain instance, which is simply returned.
          - A string that contains spaces is split at those spaces and all
            non-empty items of the resulting list are passed to KeyChain.
          - A string with '+' in it is split at those '+' and the resulting list
            is passed to KeyChain.
          - Any other string is passed to Key.
        """
        if isinstance(string, (Key, KeyChain)):
            return string
        elif ' ' in string:
            keys = (key for key in self._KEY_SPLIT_SPACE.split(string) if key)
            return KeyChain(*keys)
        elif '+' in string and len(string) >= 3:
            return KeyChain(*string.strip().split('+'))
        else:
            return Key(string)

urwid.command_map[Key('home')]           = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('end')]            = urwid.CURSOR_MAX_RIGHT
urwid.command_map[Key('ctrl-a')]         = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('ctrl-e')]         = urwid.CURSOR_MAX_RIGHT

urwid.command_map[Key('ctrl-k')]         = urwid.DELETE_TO_EOL
urwid.command_map[Key('ctrl-u')]         = urwid.DELETE_LINE
urwid.command_map[Key('ctrl-d')]         = urwid.DELETE_CHAR_UNDER_CURSOR
urwid.command_map[Key('meta-d')]         = urwid.DELETE_WORD_LEFT
urwid.command_map[Key('meta-backspace')] = urwid.DELETE_WORD_RIGHT
urwid.command_map[Key('ctrl-w')]         = urwid.DELETE_WORD_RIGHT

urwid.command_map[Key('enter')]          = urwid.ACTIVATE
urwid.command_map[Key('escape')]         = urwid.CANCEL
urwid.command_map[Key('ctrl-g')]         = urwid.CANCEL
urwid.command_map[Key('ctrl-c')]         = urwid.CANCEL
urwid.command_map[Key('ctrl-l')]         = urwid.REDRAW_SCREEN
urwid.command_map[Key('tab')]            = urwid.COMPLETE_NEXT
urwid.command_map[Key('shift-tab')]      = urwid.COMPLETE_PREV


import re
import operator
class Edit_readline(urwid.Edit):
    def keypress(self, size, key):
        def move_to_next_word(forward=True):
            if forward:
                match_iterator  = re.finditer(r'(\b\W+|$)', self.edit_text, flags=re.UNICODE)
                match_positions = (m.start() for m in match_iterator)
                op = operator.gt
            else:
                match_iterator  = re.finditer(r'(\w+\b|^)', self.edit_text, flags=re.UNICODE)

def evaluate(self, key, context=DEFAULT_CONTEXT, callback=None, widget=None):
        """
        Run action that is mapped to `key` in `context`

        key: the pressed key
        context: the context `key` was pressed in
        callback: None or any callable
        widget: the widget that received `key`
        """
        if context not in self._actions:
            raise ValueError('Unknown context: {}'.format(context))

        key = Key(key)
        action = None

        # Unless we've are already started a key chain, try to find a single-key mapping
        if not self.any_keychain_started:
            log.debug('%s: Evaluating %r as single key for widget %r', context, key, widget)
            action = self._get_single_key_action(key, context)

        # Try to advance keychains only if no keychain was started previously or
        # if that previously started keychain was in the same context as we're
        # in now.
        if action is None and (self._keychain_context == self.NO_CONTEXT or
                               self._keychain_context == context):
            log.debug('%s: Evaluating %r as chain key for widget %r', context, key, widget)
            action = self._get_keychain_action(key, context)
            if action is KeyChain.ADVANCE:
                log.debug('%s:   %r was used to advance a keychain; locking context', context, key)

def __new__(cls, *keys):
        obj = super().__new__(cls, (Key(k) for k in keys))
        if len(keys) < 2:
            raise ValueError('Not enough keys to make a chain: %s' % str(obj))
        return obj

urwid.DELETE_WORD_RIGHT        = 'delete word right'
urwid.CANCEL                   = 'cancel'
urwid.COMPLETE_NEXT            = 'complete next'
urwid.COMPLETE_PREV            = 'complete previous'

# Remove urwid's default keybindings and create our own built-in command_map
for key in tuple(urwid.command_map._command):
    del urwid.command_map._command[key]

from .keymap import Key
urwid.command_map[Key('pgup')]           = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('pgdn')]           = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('ctrl-b')]         = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('ctrl-f')]         = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('b')]              = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('space')]          = urwid.CURSOR_PAGE_DOWN

urwid.command_map[Key('up')]             = urwid.CURSOR_UP
urwid.command_map[Key('down')]           = urwid.CURSOR_DOWN
urwid.command_map[Key('left')]           = urwid.CURSOR_LEFT
urwid.command_map[Key('right')]          = urwid.CURSOR_RIGHT
urwid.command_map[Key('meta-b')]         = urwid.CURSOR_WORD_LEFT
urwid.command_map[Key('meta-f')]         = urwid.CURSOR_WORD_RIGHT

urwid.command_map[Key('home')]           = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('end')]            = urwid.CURSOR_MAX_RIGHT
urwid.command_map[Key('ctrl-a')]         = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('ctrl-e')]         = urwid.CURSOR_MAX_RIGHT

urwid.command_map[Key('ctrl-k')]         = urwid.DELETE_TO_EOL
urwid.command_map[Key('ctrl-u')]         = urwid.DELETE_LINE
urwid.command_map[Key('ctrl-d')]         = urwid.DELETE_CHAR_UNDER_CURSOR

# Remove urwid's default keybindings and create our own built-in command_map
for key in tuple(urwid.command_map._command):
    del urwid.command_map._command[key]

from .keymap import Key
urwid.command_map[Key('pgup')]           = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('pgdn')]           = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('ctrl-b')]         = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('ctrl-f')]         = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('b')]              = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('space')]          = urwid.CURSOR_PAGE_DOWN

urwid.command_map[Key('up')]             = urwid.CURSOR_UP
urwid.command_map[Key('down')]           = urwid.CURSOR_DOWN
urwid.command_map[Key('left')]           = urwid.CURSOR_LEFT
urwid.command_map[Key('right')]          = urwid.CURSOR_RIGHT
urwid.command_map[Key('meta-b')]         = urwid.CURSOR_WORD_LEFT
urwid.command_map[Key('meta-f')]         = urwid.CURSOR_WORD_RIGHT

urwid.command_map[Key('home')]           = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('end')]            = urwid.CURSOR_MAX_RIGHT
urwid.command_map[Key('ctrl-a')]         = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('ctrl-e')]         = urwid.CURSOR_MAX_RIGHT

urwid.command_map[Key('ctrl-k')]         = urwid.DELETE_TO_EOL
urwid.command_map[Key('ctrl-u')]         = urwid.DELETE_LINE
urwid.command_map[Key('ctrl-d')]         = urwid.DELETE_CHAR_UNDER_CURSOR
urwid.command_map[Key('meta-d')]         = urwid.DELETE_WORD_LEFT
urwid.command_map[Key('meta-backspace')] = urwid.DELETE_WORD_RIGHT
urwid.command_map[Key('ctrl-w')]         = urwid.DELETE_WORD_RIGHT

urwid.command_map[Key('up')]             = urwid.CURSOR_UP
urwid.command_map[Key('down')]           = urwid.CURSOR_DOWN
urwid.command_map[Key('left')]           = urwid.CURSOR_LEFT
urwid.command_map[Key('right')]          = urwid.CURSOR_RIGHT
urwid.command_map[Key('meta-b')]         = urwid.CURSOR_WORD_LEFT
urwid.command_map[Key('meta-f')]         = urwid.CURSOR_WORD_RIGHT

urwid.command_map[Key('home')]           = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('end')]            = urwid.CURSOR_MAX_RIGHT
urwid.command_map[Key('ctrl-a')]         = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('ctrl-e')]         = urwid.CURSOR_MAX_RIGHT

urwid.command_map[Key('ctrl-k')]         = urwid.DELETE_TO_EOL
urwid.command_map[Key('ctrl-u')]         = urwid.DELETE_LINE
urwid.command_map[Key('ctrl-d')]         = urwid.DELETE_CHAR_UNDER_CURSOR
urwid.command_map[Key('meta-d')]         = urwid.DELETE_WORD_LEFT
urwid.command_map[Key('meta-backspace')] = urwid.DELETE_WORD_RIGHT
urwid.command_map[Key('ctrl-w')]         = urwid.DELETE_WORD_RIGHT

urwid.command_map[Key('enter')]          = urwid.ACTIVATE
urwid.command_map[Key('escape')]         = urwid.CANCEL
urwid.command_map[Key('ctrl-g')]         = urwid.CANCEL
urwid.command_map[Key('ctrl-c')]         = urwid.CANCEL
urwid.command_map[Key('ctrl-l')]         = urwid.REDRAW_SCREEN
urwid.command_map[Key('tab')]            = urwid.COMPLETE_NEXT
urwid.command_map[Key('shift-tab')]      = urwid.COMPLETE_PREV


import re
import operator
class Edit_readline(urwid.Edit):
    def keypress(self, size, key):

urwid.DELETE_TO_EOL            = 'delete to end of line'
urwid.DELETE_LINE              = 'delete line'
urwid.DELETE_CHAR_UNDER_CURSOR = 'delete char under cursor'
urwid.DELETE_WORD_LEFT         = 'delete word left'
urwid.DELETE_WORD_RIGHT        = 'delete word right'
urwid.CANCEL                   = 'cancel'
urwid.COMPLETE_NEXT            = 'complete next'
urwid.COMPLETE_PREV            = 'complete previous'

# Remove urwid's default keybindings and create our own built-in command_map
for key in tuple(urwid.command_map._command):
    del urwid.command_map._command[key]

from .keymap import Key
urwid.command_map[Key('pgup')]           = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('pgdn')]           = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('ctrl-b')]         = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('ctrl-f')]         = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('b')]              = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('space')]          = urwid.CURSOR_PAGE_DOWN

urwid.command_map[Key('up')]             = urwid.CURSOR_UP
urwid.command_map[Key('down')]           = urwid.CURSOR_DOWN
urwid.command_map[Key('left')]           = urwid.CURSOR_LEFT
urwid.command_map[Key('right')]          = urwid.CURSOR_RIGHT
urwid.command_map[Key('meta-b')]         = urwid.CURSOR_WORD_LEFT
urwid.command_map[Key('meta-f')]         = urwid.CURSOR_WORD_RIGHT

urwid.command_map[Key('home')]           = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('end')]            = urwid.CURSOR_MAX_RIGHT
urwid.command_map[Key('ctrl-a')]         = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('ctrl-e')]         = urwid.CURSOR_MAX_RIGHT

urwid.DELETE_WORD_LEFT         = 'delete word left'
urwid.DELETE_WORD_RIGHT        = 'delete word right'
urwid.CANCEL                   = 'cancel'
urwid.COMPLETE_NEXT            = 'complete next'
urwid.COMPLETE_PREV            = 'complete previous'

# Remove urwid's default keybindings and create our own built-in command_map
for key in tuple(urwid.command_map._command):
    del urwid.command_map._command[key]

from .keymap import Key
urwid.command_map[Key('pgup')]           = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('pgdn')]           = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('ctrl-b')]         = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('ctrl-f')]         = urwid.CURSOR_PAGE_DOWN
urwid.command_map[Key('b')]              = urwid.CURSOR_PAGE_UP
urwid.command_map[Key('space')]          = urwid.CURSOR_PAGE_DOWN

urwid.command_map[Key('up')]             = urwid.CURSOR_UP
urwid.command_map[Key('down')]           = urwid.CURSOR_DOWN
urwid.command_map[Key('left')]           = urwid.CURSOR_LEFT
urwid.command_map[Key('right')]          = urwid.CURSOR_RIGHT
urwid.command_map[Key('meta-b')]         = urwid.CURSOR_WORD_LEFT
urwid.command_map[Key('meta-f')]         = urwid.CURSOR_WORD_RIGHT

urwid.command_map[Key('home')]           = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('end')]            = urwid.CURSOR_MAX_RIGHT
urwid.command_map[Key('ctrl-a')]         = urwid.CURSOR_MAX_LEFT
urwid.command_map[Key('ctrl-e')]         = urwid.CURSOR_MAX_RIGHT

urwid.command_map[Key('ctrl-k')]         = urwid.DELETE_TO_EOL
urwid.command_map[Key('ctrl-u')]         = urwid.DELETE_LINE

def keypress(self, size, key_orig):
        keymap   = self.__keymap
        context  = self.__context
        callback = self.__callback
        key_eval = Key(key_orig)

        def try_parent_class(key, sup=super()):
            if sup.selectable():
                # mro = sup.__self_class__.mro()
                # super_cls = mro[mro.index(sup.__thisclass__) + 1]
                # log.debug('%s: Offering %r to %s.keypress()', context, key, super_cls.__name__)
                key = sup.keypress(size, key)
                # log.debug('%s: %s.keypress() returned %r', context, super_cls.__name__, key)
            return key

        log.debug('%s: %r / %r pressed', context, key_orig, key_eval)

        # Any started keychains have the highest priority
        if keymap.any_keychain_started:
            log.debug('%s: Advancing started keychain(s)', context)
            key_ = keymap.evaluate(key_eval, context=context, callback=callback, widget=self)