def METHOD_NAME(self, touch):
    if touch.grab_current == self:
        if (
            touch.ud['page'] == 'previous' and
            abs(touch.x - touch.ox) / self.width > self.swipe_threshold
        ):
            self.page -= 1
        elif (
            touch.ud['page'] == 'next' and
            abs(touch.x - touch.ox) / self.width > self.swipe_threshold
        ):
            self.page += 1
        else:
            self._trigger_layout()
        touch.ungrab(self)
    if len(self.children) > 1:
        return self.children[-self.page + 1].METHOD_NAME(touch)