'Toggle visibility of a given bar
Parameters
position :
one of: "top", "bottom", "left", "right", or "all" (default: "all")'

def cmd_hide_show_bar(self, position='all'):

    if (position in ['top', 'bottom', 'left', 'right']):
        bar = getattr(self.currentScreen, position)
        if bar:
            bar.show((not bar.is_show()))
            self.currentGroup.layoutAll()
        else:
            logger.warning(("Not    found    bar    in    position    '%s'    for    hide/show." % position))
    elif (position == 'all'):
        screen = self.currentScreen
        is_show = None
        for bar in [screen.left, screen.right, screen.top, screen.bottom]:
            if bar:
                if (is_show is None):
                    is_show = (not bar.is_show())
                bar.show(is_show)
        if (is_show is not None):
            self.currentGroup.layoutAll()
        else:
            logger.warning('Not    found    bar    for    hide/show.')
    else:
        logger.error('Invalid    position    value:{0:s}'.format(position))
