code: function (event) {
  
          event = normalizeEvent(this.dom, event);
  
          // Mark touch, which is useful in distinguish touch and
          // mouse event in upper applicatoin.
          event.zrByTouch = true;
  
          this.handler.processGesture(this, event, 'change');
  
          // Mouse move should always be triggered no matter whether
          // there is gestrue event, because mouse move and pinch may
          // be used at the same time.
          domHandlers.mousemove.call(this, event);
  
          setTouchTimer(this);
      }
docs: Touch移动响应函数
  @inner
  @param {Event} event