group.py 文件源码

def focus_selectable(self, forward=True):
        """Change focus to next selectable widget

        forward: True to select next widget, False to select previous widget

        Returns True if focus was changed, False otherwise.
        """
        op = operator.add if forward else operator.sub
        max_pos = len(self._main.contents)-1
        new_pos = None
        pos = self.focus_position
        while 0 < pos < max_pos:
            pos = op(pos, 1)
            item = self._get_item_by_position(pos, visible=True)
            if item is not None and item['widget'].selectable():
                new_pos = pos
                break

        if new_pos is not None:
            self.focus_position = new_pos
            return True
        return False