overscroll/lib/utils/dom/contains.js

scroll

"use strict";

exports.__esModule = true;
exports["default"] = contains;

// 检测 parentNode 元素包含 childNode 元素
function contains(parentNode, childNode) {
  // 标准浏览器支持compareDocumentPosition
  if (parentNode.compareDocumentPosition) {
    return !!(parentNode.compareDocumentPosition(childNode) & 16);
  }

  // IE支持contains
  else if (parentNode.contains) {
      return parentNode !== childNode && parentNode.contains(childNode);
    }

  return false;
}