in-viewport-2.js

const {
  get,
  set,
  setProperties,
  computed,
  run,
  on,
  $,
} = Ember;

const {
  scheduleOnce,
  debounce,
  bind,
  next
} = run;

const { not }     = computed;
const { forEach } = Ember.EnumerableUtils;

const listeners = [
  { context: window,   event: 'scroll.scrollable' },
  { context: window,   event: 'resize.resizable' },
  { context: document, event: 'touchmove.scrollable' }
];

let rAFIDS = {};