Function getScroll

app/src/static/js/react-bootstrap.js:3276–3288

* Gets the scroll value of the given element in the given side (top and left) * @method * @memberof Popper.Utils * @argument {Element} element * @argument {String} side `top` or `left` * @returns {number} amount of scrolled pixels

(element)

function getScroll(element) {
  var side = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'top';
  var upperSide = side === 'top' ? 'scrollTop' : 'scrollLeft';
  var nodeName = element.nodeName;

  if (nodeName === 'BODY' || nodeName === 'HTML') {
    var html = element.ownerDocument.documentElement;
    var scrollingElement = element.ownerDocument.scrollingElement || html;
    return scrollingElement[upperSide];
  }

  return element[upperSide];
}
/*
 * Sum or subtract the element scroll values (left and top) from a given rect object
 * @method