pulldown and pullup for iScroll 5

iscroll5-pullable.js

  var createPullabledScroll = function (iScroll, elem, options) {
    var scroll, pullDownReady, pullUpReady;
    // scope variable
    pullDownReady = false;
    pullUpReady = false;
    // setup the scroll object
    options.probeType = options.probeType || 2;
    scroll = new iScroll(elem, options);
    // pullDown
    if (typeof options.pullDownOffset === 'number') {
      scroll.on('scroll', function () {
        if (this.y > options.pullDownOffset && !pullDownReady) {
          pullDownReady = true;
          this._execEvent('pullDownReady');
        } else if (this.y < options.pullDownOffset && pullDownReady) {
          pullDownReady = false;
          this._execEvent('pullDownCancel');
        }
      });
      scroll.on('scrollEnd', function () {
        if (pullDownReady) {
          this._execEvent('pullDown');
          pullDownReady = false;
        }
      });
    }
    if (typeof options.pullUpOffset === 'number') {
      scroll.on('scroll', function () {
        if (this.y < (this.maxScrollY - options.pullUpOffset) && !pullUpReady) {
          pullUpReady = true;
          this._execEvent('pullUpReady');
        } else if (this.y > (this.maxScrollY + options.pullUpOffset) && pullUpReady) {
          pullUpReady = false;
          this._execEvent('pullUpCancel');
        }
      });
      scroll.on('scrollEnd', function () {
        if (pullUpReady) {
          this._execEvent('pullUp');
          pullDownReady = false;
        }
      });
    }
    return scroll;
  };