code: function(inEvent) {
        if (this.firstXY) {
          var ret;
          var scrollAxis = inEvent.currentTarget._scrollType;
          if (scrollAxis === 'none') {
  
            // this element is a touch-action: none, should never scroll
            ret = false;
          } else if (scrollAxis === 'XY') {
  
            // this element should always scroll
            ret = true;
          } else {
            var t = inEvent.changedTouches[0];
  
            // check the intended scroll axis, and other axis
            var a = scrollAxis;
            var oa = scrollAxis === 'Y' ? 'X' : 'Y';
            var da = Math.abs(t['client' + a] - this.firstXY[a]);
            var doa = Math.abs(t['client' + oa] - this.firstXY[oa]);
  
            // if delta in the scroll axis > delta other axis, scroll instead of
            // making events
            ret = da >= doa;
          }
          this.firstXY = null;
          return ret;
        }
      }
docs: For single axis scrollers, determines whether the element should emit pointer events or behave as a scroller