@xo-union/tk-component-header-nav/lib/components/HeaderNav/ResizeObserverNav/index.js

import _extends from "@babel/runtime-corejs3/helpers/esm/extends";
import _globalThis from "@babel/runtime-corejs3/core-js/global-this";
import React from "react";
import PropTypes from "prop-types";
const ResizeObserverNav = _ref => {
  let {
    isHamburgerOpenInMobile,
    children,
    ...props
  } = _ref;
  const [bottomOfHeader, setBottomOfHeader] = React.useState('65px' /* default bottom */);

  const headerNavRef = React.useRef();
  React.useEffect(() => {
    // IE 11 fix to bypass resize observer without a polyfill. This useEffect is
    // only needed for the mobile view
    if (!_globalThis.ResizeObserver) {
      return;
    }
    const resizeObserver = new ResizeObserver(() => {
      if (isHamburgerOpenInMobile) {
        const {
          bottom
        } = headerNavRef.current.getBoundingClientRect();
        setBottomOfHeader(`${bottom}px`);
      }
    });
    const {
      body
    } = document;
    resizeObserver.observe(body);

    // eslint-disable-next-line consistent-return
    return () => {
      resizeObserver.unobserve(body);
    };
  }, [isHamburgerOpenInMobile]);
  return /*#__PURE__*/React.createElement("nav", _extends({
    ref: headerNavRef,
    style: {
      '--bottom-of-header': bottomOfHeader
    }
  }, props), children);
};
process.env.NODE_ENV !== "production" ? ResizeObserverNav.propTypes = {
  children: PropTypes.node,
  isHamburgerOpenInMobile: PropTypes.bool
} : void 0;
export default ResizeObserverNav;