godot-docs/_static/js/custom.js

// Handle page scroll and adjust sidebar accordingly.

// Each page has two scrolls: the main scroll, which is moving the content of the page;
// and the sidebar scroll, which is moving the navigation in the sidebar.
// We want the logo to gradually disappear as the main content is scrolled, giving
// more room to the navigation on the left. This means adjusting the height
// available to the navigation on the fly. There is also a banner below the navigation
// that must be dealt with simultaneously.
const registerOnScrollEvent = (function(){
  // Configuration.

  // The number of pixels the user must scroll by before the logo is completely hidden.
  const scrollTopPixels = 84;
  // The target margin to be applied to the navigation bar when the logo is hidden.
  const menuTopMargin = 70;
  // The max-height offset when the logo is completely visible.
  const menuHeightOffset_default = 162;
  // The max-height offset when the logo is completely hidden.
  const menuHeightOffset_fixed = 80;
  // The distance between the two max-height offset values above; used for intermediate values.
  const menuHeightOffset_diff = (menuHeightOffset_default - menuHeightOffset_fixed);

  // Media query handler.
  return function(mediaQuery) {
    // We only apply this logic to the "desktop" resolution (defined by a media query at the bottom).
    // This handler is executed when the result of the query evaluation changes, which means that
    // the page has moved between "desktop" and "mobile" states.

    // When entering the "desktop" state, we register scroll events and adjust elements on the page.
    // When entering the "mobile" state, we clean up any registered events and restore elements on the page
    // to their initial state.

    const $window = $(window);
    const $sidebar = $('.wy-side-scroll');
    const $search = $sidebar.children('.wy-side-nav-search');
    const $menu = $sidebar.children('.wy-menu-vertical');
    const $ethical = $sidebar.children('.ethical-rtd');

    // This padding is needed to correctly adjust the height of the scrollable area in the sidebar.
    // It has to have the same height as the ethical block, if there is one.
    let $menuPadding = $menu.children('.wy-menu-ethical-padding');
    if ($menuPadding.length == 0) {
      $menuPadding = $('<div class="wy-menu-ethical-padding"></div>');
      $menu.append($menuPadding);
    }

    if (mediaQuery.matches) {
      // Entering the "desktop" state.

      // The main scroll event handler.
      // Executed as the page is scrolled and once immediately as the page enters this state.
      const handleMainScroll = (currentScroll) => {
        if (currentScroll >= scrollTopPixels) {
          // After the page is scrolled below the threshold, we fix everything in place.
          $search.css('margin-top', `-${scrollTopPixels}px`);
          $menu.css('margin-top', `${menuTopMargin}px`);
          $menu.css('max-height', `calc(100% - ${menuHeightOffset_fixed}px)`);
        }
        else {
          // Between the top of the page and the threshold we calculate intermediate values
          // to guarantee a smooth transition.
          $search.css('margin-top', `-${currentScroll}px`);
          $menu.css('margin-top', `${menuTopMargin + (scrollTopPixels - currentScroll)}px`);

          if (currentScroll > 0) {
            const scrolledPercent = (scrollTopPixels - currentScroll) / scrollTopPixels;
            const offsetValue = menuHeightOffset_fixed + menuHeightOffset_diff * scrolledPercent;
            $menu.css('max-height', `calc(100% - ${offsetValue}px)`);
          } else {
            $menu.css('max-height', `calc(100% - ${menuHeightOffset_default}px)`);
          }
        }
      };

      // The sidebar scroll event handler.
      // Executed as the sidebar is scrolled as well as after the main scroll. This is needed
      // because the main scroll can affect the scrollable area of the sidebar.
      const handleSidebarScroll = () => {
        const menuElement = $menu.get(0);
        const menuScrollTop = $menu.scrollTop();
        const menuScrollBottom = menuElement.scrollHeight - (menuScrollTop + menuElement.offsetHeight);

        // As the navigation is scrolled we add a shadow to the top bar hanging over it.
        if (menuScrollTop > 0) {
          $search.addClass('fixed-and-scrolled');
        } else {
          $search.removeClass('fixed-and-scrolled');
        }

        // Near the bottom we start moving the sidebar banner into view.
        if (menuScrollBottom < ethicalOffsetBottom) {
          $ethical.css('display', 'block');
          $ethical.css('margin-top', `-${ethicalOffsetBottom - menuScrollBottom}px`);
        } else {
          $ethical.css('display', 'none');
          $ethical.css('margin-top', '0px');
        }
      };

      $search.addClass('fixed');
      $ethical.addClass('fixed');

      // Adjust the inner height of navigation so that the banner can be overlaid there later.
      const ethicalOffsetBottom = $ethical.height() || 0;
      if (ethicalOffsetBottom) {
        $menuPadding.css('height', `${ethicalOffsetBottom}px`);
      } else {
        $menuPadding.css('height', `0px`);
      }

      $window.scroll(function() {
        handleMainScroll(window.scrollY);
        handleSidebarScroll();
      });

      $menu.scroll(function() {
        handleSidebarScroll();
      });

      handleMainScroll(window.scrollY);
      handleSidebarScroll();
    } else {
      // Entering the "mobile" state.

      $window.unbind('scroll');
      $menu.unbind('scroll');

      $search.removeClass('fixed');
      $ethical.removeClass('fixed');

      $search.css('margin-top', `0px`);
      $menu.css('margin-top', `0px`);
      $menu.css('max-height', 'initial');
      $menuPadding.css('height', `0px`);
      $ethical.css('margin-top', '0px');
      $ethical.css('display', 'block');
    }
  };
})();

// Subscribe to DOM changes in the sidebar container, because there is a
// banner that gets added at a later point, that we might not catch otherwise.
const registerSidebarObserver = (function(){
  return function(callback) {
    const sidebarContainer = document.querySelector('.wy-side-scroll');

    let sidebarEthical = null;
    const registerEthicalObserver = () => {
      if (sidebarEthical) {
        // Do it only once.
        return;
      }

      sidebarEthical = sidebarContainer.querySelector('.ethical-rtd');
      if (!sidebarEthical) {
        // Do it only after we have the element there.
        return;
      }

      // This observer watches over the ethical block in sidebar, and all of its subtree.
      const ethicalObserverConfig = { childList: true, subtree: true };
      const ethicalObserverCallback = (mutationsList, observer) => {
        for (let mutation of mutationsList) {
          if (mutation.type !== 'childList') {
            continue;
          }

          callback();
        }
      };

      const ethicalObserver = new MutationObserver(ethicalObserverCallback);
      ethicalObserver.observe(sidebarEthical, ethicalObserverConfig);
    };
    registerEthicalObserver();

    // This observer watches over direct children of the main sidebar container.
    const observerConfig = { childList: true };
    const observerCallback = (mutationsList, observer) => {
      for (let mutation of mutationsList) {
        if (mutation.type !== 'childList') {
          continue;
        }

        callback();
        registerEthicalObserver();
      }
    };

    const observer = new MutationObserver(observerCallback);
    observer.observe(sidebarContainer, observerConfig);

    // Default TOC tree has links that immediately navigate to the selected page. Our
    // theme adds an extra button to fold and unfold the tree without navigating away.
    // But that means that the buttons are added after the initial load, so we need to
    // improvise to detect clicks on these buttons.
    const scrollElement = document.querySelector('.wy-menu-vertical');
    const registerLinkHandler = (linkChildren) => {
      linkChildren.forEach(it => {
        if (it.nodeType === Node.ELEMENT_NODE && it.classList.contains('toctree-expand')) {
          it.addEventListener('click', () => {
            // Toggling a different item will close the currently opened one,
            // which may shift the clicked item out of the view. We correct for that.
            const menuItem = it.parentNode;
            const baseScrollOffset = scrollElement.scrollTop + scrollElement.offsetTop;
            const maxScrollOffset = baseScrollOffset + scrollElement.offsetHeight;

            if (menuItem.offsetTop < baseScrollOffset || menuItem.offsetTop > maxScrollOffset) {
              menuItem.scrollIntoView();
            }

            callback();
          });
        }
      });
    }

    const navigationSections = document.querySelectorAll('.wy-menu-vertical ul');
    navigationSections.forEach(it => {
      if (it.previousSibling == null || typeof it.previousSibling === 'undefined' || it.previousSibling.tagName != 'A') {
        return;
      }

      const navigationLink = it.previousSibling;
      registerLinkHandler(navigationLink.childNodes);

      const linkObserverConfig = { childList: true };
      const linkObserverCallback = (mutationsList, observer) => {
        for (let mutation of mutationsList) {
          registerLinkHandler(mutation.addedNodes);
        }
      };

      const linkObserver = new MutationObserver(linkObserverCallback);
      linkObserver.observe(navigationLink, linkObserverConfig);
    });
  };
})();

$(document).ready(() => {
  // Remove the search match highlights from the page, and adjust the URL in the
  // navigation history.
  const url = new URL(location.href);
  if (url.searchParams.has('highlight')) {
    Documentation.hideSearchWords();
  }

  // Initialize handlers for page scrolling and our custom sidebar.
  const mediaQuery = window.matchMedia('only screen and (min-width: 769px)');

  registerOnScrollEvent(mediaQuery);
  mediaQuery.addListener(registerOnScrollEvent);

  registerSidebarObserver(() => {
    registerOnScrollEvent(mediaQuery);
  });

  // Add line-break suggestions to the sidebar navigation items in the class reference section.
  //
  // Some class reference pages have very long PascalCase names, such as
  //    VisualShaderNodeCurveXYZTexture
  // Those create issues for our layout, as we can neither make them wrap with CSS without
  // breaking normal article titles, nor is it good to have them overflow their containers.
  // So we use a <wbr> tag to insert mid-word suggestions for appropriate splits, so the browser
  // knows that it's okay to split it like
  //    Visual Shader Node Curve XYZTexture
  // and add a new line at an opportune moment.
  const classReferenceLinks = document.querySelectorAll('.wy-menu-vertical > ul:last-of-type .reference.internal');
  for (const linkItem of classReferenceLinks) {
    let textNode = null;
    linkItem.childNodes.forEach(it => {
      if (it.nodeType === Node.TEXT_NODE) {
        // If this is a text node and if it needs to be updated, store a reference.
        let text = it.textContent;
        if (!(text.includes(" ") || text.length < 10)) {
          textNode = it;
        }
      }
    });

    if (textNode != null) {
        let text = textNode.textContent;
        // Add suggested line-breaks and replace the original text.
        // The regex looks for a lowercase letter followed by a number or an uppercase
        // letter. We avoid splitting at the last character in the name, though.
        text = text.replace(/([a-z])([A-Z0-9](?!$))/gm, '$1<wbr>$2');

        linkItem.removeChild(textNode);
        linkItem.insertAdjacentHTML('beforeend', text);
    }
  }

  // See `godot_is_latest` in conf.py
  const isLatest = document.querySelector('meta[name=doc_is_latest]').content.toLowerCase() === 'true';
  if (isLatest) {
    // Add a compatibility notice using JavaScript so it doesn't end up in the
    // automatically generated `meta description` tag.

    const baseUrl = [location.protocol, '//', location.host, location.pathname].join('');
    // These lines only work as expected in the production environment, can't test this locally.
    const fallbackUrl = baseUrl.replace('/latest/', '/stable/');
    const homeUrl = baseUrl.split('/latest/')[0] + '/stable/';
    const searchUrl = homeUrl + 'search.html?q=';

    const noticeLink = document.querySelector('.latest-notice-link');

    // Insert a placeholder to display as we're making a request.
    noticeLink.innerHTML = `
    Checking the <a class="reference" href="${homeUrl}">stable version</a>
    of the documentation...
    `;

    // Make a HEAD request to the possible stable URL to check if the page exists.
    fetch(fallbackUrl, { method: 'HEAD' })
      .then((res) => {
        // We only check the HTTP status, which should tell us if the link is valid or not.
        if (res.status === 200) {
          noticeLink.innerHTML = `
          See the <a class="reference" href="${fallbackUrl}">stable version</a>
          of this documentation page instead.
          `;
        } else {
          // Err, just to fallthrough to catch.
          throw Error('Bad request');
        }
      })
      .catch((err) => {
        let message = `
        This page does not exist in the <a class="reference" href="${homeUrl}">stable version</a>
        of the documentation.
        `;

        // Also suggest a search query using the page's title. It should work with translations as well.
        // Note that we can't use the title tag as it has a permanent suffix. OG title doesn't, though.
        const titleMeta = document.querySelector('meta[property="og:title"]');
        if (typeof titleMeta !== 'undefined') {
          const pageTitle = titleMeta.getAttribute('content');
          message += `
          You can try searching for "<a class="reference" href="${searchUrl + encodeURIComponent(pageTitle)}">${pageTitle}</a>" instead.
          `;
        }

        noticeLink.innerHTML = message;
      });
  }

  // Load instant.page to prefetch pages upon hovering. This makes navigation feel
  // snappier. The script is dynamically appended as Read the Docs doesn't have
  // a way to add scripts with a "module" attribute.
  const instantPageScript = document.createElement('script');
  instantPageScript.toggleAttribute('module');
  /*! instant.page v5.1.0 - (C) 2019-2020 Alexandre Dieulot - https://instant.page/license */
  instantPageScript.innerText = 'let t,e;const n=new Set,o=document.createElement("link"),i=o.relList&&o.relList.supports&&o.relList.supports("prefetch")&&window.IntersectionObserver&&"isIntersecting"in IntersectionObserverEntry.prototype,s="instantAllowQueryString"in document.body.dataset,a="instantAllowExternalLinks"in document.body.dataset,r="instantWhitelist"in document.body.dataset,c="instantMousedownShortcut"in document.body.dataset,d=1111;let l=65,u=!1,f=!1,m=!1;if("instantIntensity"in document.body.dataset){const t=document.body.dataset.instantIntensity;if("mousedown"==t.substr(0,"mousedown".length))u=!0,"mousedown-only"==t&&(f=!0);else if("viewport"==t.substr(0,"viewport".length))navigator.connection&&(navigator.connection.saveData||navigator.connection.effectiveType&&navigator.connection.effectiveType.includes("2g"))||("viewport"==t?document.documentElement.clientWidth*document.documentElement.clientHeight<45e4&&(m=!0):"viewport-all"==t&&(m=!0));else{const e=parseInt(t);isNaN(e)||(l=e)}}if(i){const n={capture:!0,passive:!0};if(f||document.addEventListener("touchstart",function(t){e=performance.now();const n=t.target.closest("a");if(!h(n))return;v(n.href)},n),u?c||document.addEventListener("mousedown",function(t){const e=t.target.closest("a");if(!h(e))return;v(e.href)},n):document.addEventListener("mouseover",function(n){if(performance.now()-e<d)return;const o=n.target.closest("a");if(!h(o))return;o.addEventListener("mouseout",p,{passive:!0}),t=setTimeout(()=>{v(o.href),t=void 0},l)},n),c&&document.addEventListener("mousedown",function(t){if(performance.now()-e<d)return;const n=t.target.closest("a");if(t.which>1||t.metaKey||t.ctrlKey)return;if(!n)return;n.addEventListener("click",function(t){1337!=t.detail&&t.preventDefault()},{capture:!0,passive:!1,once:!0});const o=new MouseEvent("click",{view:window,bubbles:!0,cancelable:!1,detail:1337});n.dispatchEvent(o)},n),m){let t;(t=window.requestIdleCallback?t=>{requestIdleCallback(t,{timeout:1500})}:t=>{t()})(()=>{const t=new IntersectionObserver(e=>{e.forEach(e=>{if(e.isIntersecting){const n=e.target;t.unobserve(n),v(n.href)}})});document.querySelectorAll("a").forEach(e=>{h(e)&&t.observe(e)})})}}function p(e){e.relatedTarget&&e.target.closest("a")==e.relatedTarget.closest("a")||t&&(clearTimeout(t),t=void 0)}function h(t){if(t&&t.href&&(!r||"instant"in t.dataset)&&(a||t.origin==location.origin||"instant"in t.dataset)&&["http:","https:"].includes(t.protocol)&&("http:"!=t.protocol||"https:"!=location.protocol)&&(s||!t.search||"instant"in t.dataset)&&!(t.hash&&t.pathname+t.search==location.pathname+location.search||"noInstant"in t.dataset))return!0}function v(t){if(n.has(t))return;const e=document.createElement("link");e.rel="prefetch",e.href=t,document.head.appendChild(e),n.add(t)}';
  document.head.appendChild(instantPageScript);

  // Make sections in the sidebar togglable.
  let hasCurrent = false;
  let menuHeaders = document.querySelectorAll('.wy-menu-vertical .caption[role=heading]');
  menuHeaders.forEach(it => {
      let connectedMenu = it.nextElementSibling;

      // Enable toggling.
      it.addEventListener('click', () => {
          if (connectedMenu.classList.contains('active')) {
            connectedMenu.classList.remove('active');
            it.classList.remove('active');
          } else {
            connectedMenu.classList.add('active');
            it.classList.add('active');
          }

          // Hide other sections.
          menuHeaders.forEach(ot => {
            if (ot !== it && ot.classList.contains('active')) {
              ot.nextElementSibling.classList.remove('active');
              ot.classList.remove('active');
            }
          });

          registerOnScrollEvent(mediaQuery);
      }, true);

      // Set the default state, expand our current section.
      if (connectedMenu.classList.contains('current')) {
        connectedMenu.classList.add('active');
        it.classList.add('active');

        hasCurrent = true;
      }
  });

  // Unfold the first (general information) section on the home page.
  if (!hasCurrent && menuHeaders.length > 0) {
    menuHeaders[0].classList.add('active');
    menuHeaders[0].nextElementSibling.classList.add('active');

    registerOnScrollEvent(mediaQuery);
  }
});

// Override the default implementation from doctools.js to avoid this behavior.
Documentation.highlightSearchWords = function() {
  // Nope.
}