in-viewport-setup.js

scrollTimeout:      100,
boundingClientRect: 0,
windowHeight:       0,
windowWidth:        0,

_updateBoundingClientRect: function() {
  var el;
  el = this.$()[0];
  this.set('boundingClientRect', el.getBoundingClientRect());
},

_setup: (function() {
  return Ember.run.scheduleOnce('afterRender', this, function() {
    this._updateBoundingClientRect();
    this.set('windowHeight', window.innerHeight || document.documentElement.clientHeight);
    this.set('windowWidth', window.innerWidth || document.documentElement.clientWidth);
  });
}).on('didInsertElement'),