react-lazyload/lib/utils/scrollParent.js

Lazyload your components, images or anything where performance matters.

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

/**
 * @fileOverview Find scroll parent
 */

exports.default = function (node) {
  if (!(node instanceof HTMLElement)) {
    return document.documentElement;
  }

  var excludeStaticParent = node.style.position === 'absolute';
  var overflowRegex = /(scroll|auto)/;
  var parent = node;

  while (parent) {
    if (!parent.parentNode) {
      return node.ownerDocument || document.documentElement;
    }

    var style = window.getComputedStyle(parent);
    var position = style.position;
    var overflow = style.overflow;
    var overflowX = style['overflow-x'];
    var overflowY = style['overflow-y'];

    if (position === 'static' && excludeStaticParent) {
      parent = parent.parentNode;
      continue;
    }

    if (overflowRegex.test(overflow) && overflowRegex.test(overflowX) && overflowRegex.test(overflowY)) {
      return parent;
    }

    parent = parent.parentNode;
  }

  return node.ownerDocument || node.documentElement || document.documentElement;
};