         return super().pointer_down(e)      @event.emitter     def pointer_move(self, e):         if self._dragging is not None:             e.stopPropagation()             ref_value, x0 = self._dragging[0], self._dragging[0]             self._dragging = ref_value, x0, True  # mark as moved             x0 = e.changedTouches[0].clientX if e.changedTouches else e.clientX             mi, ma = self.min, self.max             value_diff = (x0 - x0) / self._getgutter().clientWidth * (ma - mi)             