widgets.py 文件源码

def __init__(self, *args, **kwargs):
        # Compute selected and unselected values
        options = kwargs.get('options', {})
        if isinstance(options, list):
            options = named_objs([(opt, opt) for opt in options])
        self._reverse_lookup = {v: k for k, v in options.items()}
        selected = [self._reverse_lookup[v] for v in kwargs.get('value', [])]
        unselected = [k for k in options if k not in selected]

        # Define whitelist and blacklist
        self._lists = {False: SelectMultiple(options=unselected),
                       True: SelectMultiple(options=selected)}

        self._lists[False].observe(self._update_selection, 'value')
        self._lists[True].observe(self._update_selection, 'value')

        # Define buttons
        button_layout = Layout(width='50px')
        self._buttons = {False: Button(description='<<', layout=button_layout),
                         True: Button(description='>>', layout=button_layout)}
        self._buttons[False].on_click(self._apply_selection)
        self._buttons[True].on_click(self._apply_selection)

        # Define search
        self._search = {False: Text(placeholder='Filter available options'),
                        True: Text(placeholder='Filter selected options')}
        self._search[False].observe(self._filter_options, 'value')
        self._search[True].observe(self._filter_options, 'value')

        # Define Layout
        no_margin = Layout(margin='0')
        row_layout = Layout(margin='0', display='flex', justify_content='space-between')

        search_row = HBox([self._search[False], self._search[True]])
        search_row.layout = row_layout
        button_box = VBox([self._buttons[True], self._buttons[False]],
                          layout=Layout(margin='auto 0'))
        tab_row = HBox([self._lists[False], button_box, self._lists[True]])
        tab_row.layout = row_layout
        self._composite = VBox([search_row, tab_row], layout=no_margin)

        self.observe(self._update_options, 'options')
        self.observe(self._update_value, 'value')

        self._selected = {False: [], True: []}
        self._query = {False: '', True: ''}
        super(CrossSelect, self).__init__(*args, **dict(kwargs, options=options))