drupal/core/themes/olivero/js/scripts.es6.js

/* eslint-disable no-inner-declarations */
((Drupal) => {
  /**
   * Olivero helper functions.
   *
   * @namespace
   */
  Drupal.olivero = {};

  function isDesktopNav() {
    const navButtons = document.querySelector('.mobile-buttons');
    return (
      window.getComputedStyle(navButtons).getPropertyValue('display') === 'none'
    );
  }

  Drupal.olivero.isDesktopNav = isDesktopNav;

  const stickyHeaderToggleButton = document.querySelector(
    '.sticky-header-toggle',
  );
  const siteHeaderFixable = document.querySelector('.site-header__fixable');

  function stickyHeaderIsEnabled() {
    return stickyHeaderToggleButton.getAttribute('aria-checked') === 'true';
  }

  /**
   * Save the current sticky header expanded state to localStorage, and set
   * it to expire after two weeks.
   *
   * @param {boolean} expandedState - Current state of the sticky header button.
   */
  function setStickyHeaderStorage(expandedState) {
    const now = new Date();

    const item = {
      value: expandedState,
      expiry: now.getTime() + 20160000, // 2 weeks from now.
    };
    localStorage.setItem(
      'Drupal.olivero.stickyHeaderState',
      JSON.stringify(item),
    );
  }

  /**
   * Toggle the state of the sticky header between always pinned and
   * only pinned when scrolled to the top of the viewport.
   *
   * @param {boolean} pinnedState - State to change the sticky header to.
   */
  function toggleStickyHeaderState(pinnedState) {
    if (isDesktopNav()) {
      if (pinnedState === true) {
        siteHeaderFixable.classList.add('is-expanded');
      } else {
        siteHeaderFixable.classList.remove('is-expanded');
      }

      stickyHeaderToggleButton.setAttribute('aria-checked', pinnedState);
      setStickyHeaderStorage(pinnedState);
    }
  }

  /**
   * Return the sticky header's stored state from localStorage.
   *
   * @return {boolean} Stored state of the sticky header.
   */
  function getStickyHeaderStorage() {
    const stickyHeaderState = localStorage.getItem(
      'Drupal.olivero.stickyHeaderState',
    );

    if (!stickyHeaderState) return null;

    const item = JSON.parse(stickyHeaderState);
    const now = new Date();

    // Compare the expiry time of the item with the current time.
    if (now.getTime() > item.expiry) {
      // If the item is expired, delete the item from storage and return null.
      localStorage.removeItem('Drupal.olivero.stickyHeaderState');
      return null;
    }
    return item.value;
  }

  // Only enable scroll effects if the browser supports Intersection Observer.
  // @see https://github.com/w3c/IntersectionObserver/blob/master/polyfill/intersection-observer.js#L19-L21
  if (
    'IntersectionObserver' in window &&
    'IntersectionObserverEntry' in window &&
    'intersectionRatio' in window.IntersectionObserverEntry.prototype
  ) {
    const fixableElements = document.querySelectorAll('.fixable');

    function toggleDesktopNavVisibility(entries) {
      if (!isDesktopNav()) return;

      entries.forEach((entry) => {
        // FF doesn't seem to support entry.isIntersecting properly,
        // so we check the intersectionRatio.
        if (entry.intersectionRatio < 1) {
          fixableElements.forEach((el) => el.classList.add('js-fixed'));
        } else {
          fixableElements.forEach((el) => el.classList.remove('js-fixed'));
        }
      });
    }

    function getRootMargin() {
      let rootMarginTop = 72;
      const { body } = document;

      if (body.classList.contains('toolbar-fixed')) {
        rootMarginTop -= 39;
      }

      if (
        body.classList.contains('toolbar-horizontal') &&
        body.classList.contains('toolbar-tray-open')
      ) {
        rootMarginTop -= 40;
      }

      return `${rootMarginTop}px 0px 0px 0px`;
    }

    function monitorNavPosition() {
      const primaryNav = document.querySelector('.site-header');
      const options = {
        rootMargin: getRootMargin(),
        threshold: [0.999, 1],
      };

      const observer = new IntersectionObserver(
        toggleDesktopNavVisibility,
        options,
      );
      observer.observe(primaryNav);
    }

    stickyHeaderToggleButton.addEventListener('click', () => {
      toggleStickyHeaderState(!stickyHeaderIsEnabled());
    });

    // If header is pinned open and a header element gains focus, scroll to the
    // top of the page to ensure that the header elements can be seen.
    document
      .querySelector('#site-header__inner')
      .addEventListener('focusin', () => {
        if (isDesktopNav() && !stickyHeaderIsEnabled()) {
          const header = document.querySelector('#header');
          const headerNav = header.querySelector('#header-nav');
          const headerMargin = header.clientHeight - headerNav.clientHeight;
          if (window.scrollY > headerMargin) {
            window.scrollTo(0, headerMargin);
          }
        }
      });

    monitorNavPosition();
    setStickyHeaderStorage(getStickyHeaderStorage());
    toggleStickyHeaderState(getStickyHeaderStorage());
  }
})(Drupal);