wekan/client/components/mixins/infiniteScrolling.js

const peakAnticipation = 200;

Mixins.InfiniteScrolling = BlazeComponent.extendComponent({
  onCreated() {
    this._nextPeak = Infinity;
  },

  setNextPeak(v) {
    this._nextPeak = v;
  },

  getNextPeak() {
    return this._nextPeak;
  },

  resetNextPeak() {
    this._nextPeak = Infinity;
  },

  events() {
    return [
      {
        scroll(evt) {
          const domElement = evt.currentTarget;
          let altitude = domElement.scrollTop + domElement.offsetHeight;
          altitude += peakAnticipation;
          if (altitude >= this.callFirstWith(null, 'getNextPeak')) {
            this.mixinParent().callFirstWith(null, 'reachNextPeak');
          }
        },
      },
    ];
  },
});