src/librustdoc/html/static/js/storage.js - rust-lang/rust - Git at Google

 // storage.js is loaded in the `<head>` of all rustdoc pages and doesn't
 // use `async` or `defer`. That means it blocks further parsing and rendering
 // of the page: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script.
 // This makes it the correct place to act on settings that affect the display of
 // the page, so we don't see major layout changes during the load of the page.
 "use strict";

 /**
  * @import * as rustdoc from "./rustdoc.d.ts";
  * @import * as stringdex from "./stringdex.d.ts";
  */

 const builtinThemes = ["light", "dark", "ayu"];
 const darkThemes = ["dark", "ayu"];
 window.currentTheme = (function() {
     const currentTheme = document.getElementById("themeStyle");
     return currentTheme instanceof HTMLLinkElement ? currentTheme : null;
 })();

 const settingsDataset = (function() {
     const settingsElement = document.getElementById("default-settings");
     return settingsElement && settingsElement.dataset ? settingsElement.dataset : null;
 })();

 /**
  * Assert that the passed value is nonnull, then return it.
  *
  * Takes an optional error message argument.
  *
  * Must be defined in this file, as it is loaded before all others.
  *
  * @template T
  * @param {T|null} x
  * @param {string=} msg
  * @returns T
  */
 // used in other files, not yet used in this one.
 // eslint-disable-next-line no-unused-vars
 function nonnull(x, msg) {
     if (x === null) {
         throw (msg || "unexpected null value!");
     } else {
         return x;
     }
 }

 /**
  * Assert that the passed value is not undefined, then return it.
  *
  * Takes an optional error message argument.
  *
  * Must be defined in this file, as it is loaded before all others.
  *
  * @template T
  * @param {T|undefined} x
  * @param {string=} msg
  * @returns T
  */
 // used in other files, not yet used in this one.
 // eslint-disable-next-line no-unused-vars
 function nonundef(x, msg) {
     if (x === undefined) {
         throw (msg || "unexpected null value!");
     } else {
         return x;
     }
 }

 /**
  * Get a configuration value. If it's not set, get the default.
  *
  * @param {string} settingName
  * @returns
  */
 function getSettingValue(settingName) {
     const current = getCurrentValue(settingName);
     if (current === null && settingsDataset !== null) {
         // See the comment for `default_settings.into_iter()` etc. in
         // `Options::from_matches` in `librustdoc/config.rs`.
         const def = settingsDataset[settingName.replace(/-/g,"_")];
         if (def !== undefined) {
             return def;
         }
     }
     return current;
 }

 const localStoredTheme = getSettingValue("theme");

 /**
  * Check if a DOM Element has the given class set.
  * If `elem` is null, returns false.
  *
  * @param {HTMLElement|null} elem
  * @param {string} className
  * @returns {boolean}
  */
 // eslint-disable-next-line no-unused-vars
 function hasClass(elem, className) {
     return !!elem && !!elem.classList && elem.classList.contains(className);
 }

 /**
  * Add a class to a DOM Element. If `elem` is null,
  * does nothing. This function is idempotent.
  *
  * @param {Element|null} elem
  * @param {string} className
  */
 function addClass(elem, className) {
     if (elem && elem.classList) {
         elem.classList.add(className);
     }
 }

 /**
  * Remove a class from a DOM Element. If `elem` is null,
  * does nothing. This function is idempotent.
  *
  * @param {Element|null|undefined} elem
  * @param {string} className
  */
 // eslint-disable-next-line no-unused-vars
 function removeClass(elem, className) {
     if (elem && elem.classList) {
         elem.classList.remove(className);
     }
 }

 /**
  * Run a callback for every element of an Array.
  * @param {Array<?>}                       arr  - The array to iterate over
  * @param {function(?): boolean|void} func - The callback
  */
 function onEach(arr, func) {
     for (const elem of arr) {
         if (func(elem)) {
             return true;
         }
     }
     return false;
 }

 /**
  * Turn an HTMLCollection or a NodeList into an Array, then run a callback
  * for every element. This is useful because iterating over an HTMLCollection
  * or a "live" NodeList while modifying it can be very slow.
  * https://developer.mozilla.org/en-US/docs/Web/API/HTMLCollection
  * https://developer.mozilla.org/en-US/docs/Web/API/NodeList
  * @param {NodeList|HTMLCollection} lazyArray  - An array to iterate over
  * @param {function(?): boolean|void}    func       - The callback
  */
 // eslint-disable-next-line no-unused-vars
 function onEachLazy(lazyArray, func) {
     return onEach(
         Array.prototype.slice.call(lazyArray),
         func);
 }

 /**
  * Set a configuration value. This uses localstorage,
  * with a `rustdoc-` prefix, to avoid clashing with other
  * web apps that may be running in the same domain (for example, mdBook).
  * If localStorage is disabled, this function does nothing.
  *
  * @param {string} name
  * @param {string|null} value
  */
 function updateLocalStorage(name, value) {
     try {
         if (value === null) {
             window.localStorage.removeItem("rustdoc-" + name);
         } else {
             window.localStorage.setItem("rustdoc-" + name, value);
         }
     } catch {
         // localStorage is not accessible, do nothing
     }
 }

 /**
  * Get a configuration value. If localStorage is disabled,
  * this function returns null. If the setting was never
  * changed by the user, it also returns null; if you want to
  * be able to use a default value, call `getSettingValue` instead.
  *
  * @param {string} name
  * @returns {string|null}
  */
 function getCurrentValue(name) {
     try {
         return window.localStorage.getItem("rustdoc-" + name);
     } catch {
         return null;
     }
 }

 /**
  * Get a value from the rustdoc-vars div, which is used to convey data from
  * Rust to the JS. If there is no such element, return null.
  *
  * @param {string} name
  * @returns {string|null}
  */
 function getVar(name) {
     const el = document.querySelector("head > meta[name='rustdoc-vars']");
     return el ? el.getAttribute("data-" + name) : null;
 }

 /**
  * Change the current theme.
  * @param {string|null} newThemeName
  * @param {boolean} saveTheme
  */
 function switchTheme(newThemeName, saveTheme) {
     const themeNames = (getVar("themes") || "").split(",").filter(t => t);
     themeNames.push(...builtinThemes);

     // Ensure that the new theme name is among the defined themes
     if (newThemeName === null || themeNames.indexOf(newThemeName) === -1) {
         return;
     }

     // If this new value comes from a system setting or from the previously
     // saved theme, no need to save it.
     if (saveTheme) {
         updateLocalStorage("theme", newThemeName);
     }

     document.documentElement.setAttribute("data-theme", newThemeName);

     if (builtinThemes.indexOf(newThemeName) !== -1) {
         if (window.currentTheme && window.currentTheme.parentNode) {
             window.currentTheme.parentNode.removeChild(window.currentTheme);
             window.currentTheme = null;
         }
     } else {
         const newHref = getVar("root-path") + encodeURIComponent(newThemeName) +
             getVar("resource-suffix") + ".css";
         if (!window.currentTheme) {
             // If we're in the middle of loading, document.write blocks
             // rendering, but if we are done, it would blank the page.
             if (document.readyState === "loading") {
                 document.write(`<link rel="stylesheet" id="themeStyle" href="${newHref}">`);
                 window.currentTheme = (function() {
                     const currentTheme = document.getElementById("themeStyle");
                     return currentTheme instanceof HTMLLinkElement ? currentTheme : null;
                 })();
             } else {
                 window.currentTheme = document.createElement("link");
                 window.currentTheme.rel = "stylesheet";
                 window.currentTheme.id = "themeStyle";
                 window.currentTheme.href = newHref;
                 document.documentElement.appendChild(window.currentTheme);
             }
         } else if (newHref !== window.currentTheme.href) {
             window.currentTheme.href = newHref;
         }
     }
 }

 const updateTheme = (function() {
     // only listen to (prefers-color-scheme: dark) because light is the default
     const mql = window.matchMedia("(prefers-color-scheme: dark)");

     /**
      * Update the current theme to match whatever the current combination of
      * * the preference for using the system theme
      *   (if this is the case, the value of preferred-light-theme, if the
      *   system theme is light, otherwise if dark, the value of
      *   preferred-dark-theme.)
      * * the preferred theme
      * … dictates that it should be.
      */
     function updateTheme() {
         // maybe the user has disabled the setting in the meantime!
         if (getSettingValue("use-system-theme") !== "false") {
             const lightTheme = getSettingValue("preferred-light-theme") || "light";
             const darkTheme = getSettingValue("preferred-dark-theme") || "dark";
             updateLocalStorage("use-system-theme", "true");

             // use light theme if user prefers it, or has no preference
             switchTheme(mql.matches ? darkTheme : lightTheme, true);
             // note: we save the theme so that it doesn't suddenly change when
             // the user disables "use-system-theme" and reloads the page or
             // navigates to another page
         } else {
             switchTheme(getSettingValue("theme"), false);
         }
     }

     mql.addEventListener("change", updateTheme);

     return updateTheme;
 })();

 // @ts-ignore
 if (getSettingValue("use-system-theme") !== "false" && window.matchMedia) {
     // update the preferred dark theme if the user is already using a dark theme
     // See https://github.com/rust-lang/rust/pull/77809#issuecomment-707875732
     if (getSettingValue("use-system-theme") === null
         && getSettingValue("preferred-dark-theme") === null
         && localStoredTheme !== null
         && darkThemes.indexOf(localStoredTheme) >= 0) {
         updateLocalStorage("preferred-dark-theme", localStoredTheme);
     }
 }

 updateTheme();

 // Hide, show, and resize the sidebar at page load time
 //
 // This needs to be done here because this JS is render-blocking,
 // so that the sidebar doesn't "jump" after appearing on screen.
 // The user interaction to change this is set up in main.js.
 //
 // At this point in page load, `document.body` is not available yet.
 // Set a class on the `<html>` element instead.
 if (getSettingValue("source-sidebar-show") === "true") {
     addClass(document.documentElement, "src-sidebar-expanded");
 }
 if (getSettingValue("hide-sidebar") === "true") {
     addClass(document.documentElement, "hide-sidebar");
 }
 if (getSettingValue("hide-toc") === "true") {
     addClass(document.documentElement, "hide-toc");
 }
 if (getSettingValue("hide-modnav") === "true") {
     addClass(document.documentElement, "hide-modnav");
 }
 if (getSettingValue("sans-serif-fonts") === "true") {
     addClass(document.documentElement, "sans-serif");
 }
 if (getSettingValue("word-wrap-source-code") === "true") {
     addClass(document.documentElement, "word-wrap-source-code");
 }
 function updateSidebarWidth() {
     const desktopSidebarWidth = getSettingValue("desktop-sidebar-width");
     if (desktopSidebarWidth && desktopSidebarWidth !== "null") {
         document.documentElement.style.setProperty(
             "--desktop-sidebar-width",
             desktopSidebarWidth + "px",
         );
     }
     const srcSidebarWidth = getSettingValue("src-sidebar-width");
     if (srcSidebarWidth && srcSidebarWidth !== "null") {
         document.documentElement.style.setProperty(
             "--src-sidebar-width",
             srcSidebarWidth + "px",
         );
     }
 }
 updateSidebarWidth();

 // If we navigate away (for example to a settings page), and then use the back or
 // forward button to get back to a page, the theme may have changed in the meantime.
 // But scripts may not be re-loaded in such a case due to the bfcache
 // (https://web.dev/bfcache/). The "pageshow" event triggers on such navigations.
 // Use that opportunity to update the theme.
 // We use a setTimeout with a 0 timeout here to put the change on the event queue.
 // For some reason, if we try to change the theme while the `pageshow` event is
 // running, it sometimes fails to take effect. The problem manifests on Chrome,
 // specifically when talking to a remote website with no caching.
 window.addEventListener("pageshow", ev => {
     if (ev.persisted) {
         setTimeout(updateTheme, 0);
         setTimeout(updateSidebarWidth, 0);
     }
 });

 // Custom elements are used to insert some JS-dependent features into Rustdoc,
 // because the [parser] runs the connected callback
 // synchronously. It needs to be added synchronously so that nothing below it
 // becomes visible until after it's done. Otherwise, you get layout jank.
 //
 // That's also why this is in storage.js and not main.js.
 //
 // [parser]: https://html.spec.whatwg.org/multipage/parsing.html
 class RustdocToolbarElement extends HTMLElement {
     constructor() {
         super();
     }
     connectedCallback() {
         // Avoid replacing the children after they're already here.
         if (this.firstElementChild) {
             return;
         }
         const rootPath = getVar("root-path");
         const currentUrl = window.location.href.split("?")[0].split("#")[0];
         this.innerHTML = `
         <div id="search-button" tabindex="-1">
             <a href="${currentUrl}?search="><span class="label">Search</span></a>
         </div>
         <div class="settings-menu" tabindex="-1">
             <a href="${rootPath}settings.html"><span class="label">Settings</span></a>
         </div>
         <div class="help-menu" tabindex="-1">
             <a href="${rootPath}help.html"><span class="label">Help</span></a>
         </div>
         <button id="toggle-all-docs"
 title="Collapse sections (shift-click to also collapse impl blocks)"><span
 class="label">Summary</span></button>`;
     }
 }
 window.customElements.define("rustdoc-toolbar", RustdocToolbarElement);
 class RustdocTopBarElement extends HTMLElement {
     constructor() {
         super();
     }
     connectedCallback() {
         const rootPath = getVar("root-path");
         const tmplt = document.createElement("template");
         tmplt.innerHTML = `
         <slot name="sidebar-menu-toggle"></slot>
         <slot></slot>
         <slot name="settings-menu"></slot>
         <slot name="help-menu"></slot>
         `;
         const shadow = this.attachShadow({ mode: "open" });
         shadow.appendChild(tmplt.content.cloneNode(true));
         this.innerHTML += `
         <button class="sidebar-menu-toggle" slot="sidebar-menu-toggle" title="show sidebar">
         </button>
         <div class="settings-menu" slot="settings-menu" tabindex="-1">
             <a href="${rootPath}settings.html"><span class="label">Settings</span></a>
         </div>
         <div class="help-menu" slot="help-menu" tabindex="-1">
             <a href="${rootPath}help.html"><span class="label">Help</span></a>
         </div>
         `;
     }
 }
 window.customElements.define("rustdoc-topbar", RustdocTopBarElement);
	// storage.js is loaded in the `<head>` of all rustdoc pages and doesn't
	// use `async` or `defer`. That means it blocks further parsing and rendering
	// of the page: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script.
	// This makes it the correct place to act on settings that affect the display of
	// the page, so we don't see major layout changes during the load of the page.
	"use strict";

	/**
	* @import * as rustdoc from "./rustdoc.d.ts";
	* @import * as stringdex from "./stringdex.d.ts";
	*/

	const builtinThemes = ["light", "dark", "ayu"];
	const darkThemes = ["dark", "ayu"];
	window.currentTheme = (function() {
	const currentTheme = document.getElementById("themeStyle");
	return currentTheme instanceof HTMLLinkElement ? currentTheme : null;
	})();

	const settingsDataset = (function() {
	const settingsElement = document.getElementById("default-settings");
	return settingsElement && settingsElement.dataset ? settingsElement.dataset : null;
	})();

	/**
	* Assert that the passed value is nonnull, then return it.
	*
	* Takes an optional error message argument.
	*
	* Must be defined in this file, as it is loaded before all others.
	*
	* @template T
	* @param {T\|null} x
	* @param {string=} msg
	* @returns T
	*/
	// used in other files, not yet used in this one.
	// eslint-disable-next-line no-unused-vars
	function nonnull(x, msg) {
	if (x === null) {
	throw (msg \|\| "unexpected null value!");
	} else {
	return x;
	}
	}

	/**
	* Assert that the passed value is not undefined, then return it.
	*
	* Takes an optional error message argument.
	*
	* Must be defined in this file, as it is loaded before all others.
	*
	* @template T
	* @param {T\|undefined} x
	* @param {string=} msg
	* @returns T
	*/
	// used in other files, not yet used in this one.
	// eslint-disable-next-line no-unused-vars
	function nonundef(x, msg) {
	if (x === undefined) {
	throw (msg \|\| "unexpected null value!");
	} else {
	return x;
	}
	}

	/**
	* Get a configuration value. If it's not set, get the default.
	*
	* @param {string} settingName
	* @returns
	*/
	function getSettingValue(settingName) {
	const current = getCurrentValue(settingName);
	if (current === null && settingsDataset !== null) {
	// See the comment for `default_settings.into_iter()` etc. in
	// `Options::from_matches` in `librustdoc/config.rs`.
	const def = settingsDataset[settingName.replace(/-/g,"_")];
	if (def !== undefined) {
	return def;
	}
	}
	return current;
	}

	const localStoredTheme = getSettingValue("theme");

	/**
	* Check if a DOM Element has the given class set.
	* If `elem` is null, returns false.
	*
	* @param {HTMLElement\|null} elem
	* @param {string} className
	* @returns {boolean}
	*/
	// eslint-disable-next-line no-unused-vars
	function hasClass(elem, className) {
	return !!elem && !!elem.classList && elem.classList.contains(className);
	}

	/**
	* Add a class to a DOM Element. If `elem` is null,
	* does nothing. This function is idempotent.
	*
	* @param {Element\|null} elem
	* @param {string} className
	*/
	function addClass(elem, className) {
	if (elem && elem.classList) {
	elem.classList.add(className);
	}
	}

	/**
	* Remove a class from a DOM Element. If `elem` is null,
	* does nothing. This function is idempotent.
	*
	* @param {Element\|null\|undefined} elem
	* @param {string} className
	*/
	// eslint-disable-next-line no-unused-vars
	function removeClass(elem, className) {
	if (elem && elem.classList) {
	elem.classList.remove(className);
	}
	}

	/**
	* Run a callback for every element of an Array.
	* @param {Array<?>} arr - The array to iterate over
	* @param {function(?): boolean\|void} func - The callback
	*/
	function onEach(arr, func) {
	for (const elem of arr) {
	if (func(elem)) {
	return true;
	}
	}
	return false;
	}

	/**
	* Turn an HTMLCollection or a NodeList into an Array, then run a callback
	* for every element. This is useful because iterating over an HTMLCollection
	* or a "live" NodeList while modifying it can be very slow.
	* https://developer.mozilla.org/en-US/docs/Web/API/HTMLCollection
	* https://developer.mozilla.org/en-US/docs/Web/API/NodeList
	* @param {NodeList\|HTMLCollection} lazyArray - An array to iterate over
	* @param {function(?): boolean\|void} func - The callback
	*/
	// eslint-disable-next-line no-unused-vars
	function onEachLazy(lazyArray, func) {
	return onEach(
	Array.prototype.slice.call(lazyArray),
	func);
	}

	/**
	* Set a configuration value. This uses localstorage,
	* with a `rustdoc-` prefix, to avoid clashing with other
	* web apps that may be running in the same domain (for example, mdBook).
	* If localStorage is disabled, this function does nothing.
	*
	* @param {string} name
	* @param {string\|null} value
	*/
	function updateLocalStorage(name, value) {
	try {
	if (value === null) {
	window.localStorage.removeItem("rustdoc-" + name);
	} else {
	window.localStorage.setItem("rustdoc-" + name, value);
	}
	} catch {
	// localStorage is not accessible, do nothing
	}
	}

	/**
	* Get a configuration value. If localStorage is disabled,
	* this function returns null. If the setting was never
	* changed by the user, it also returns null; if you want to
	* be able to use a default value, call `getSettingValue` instead.
	*
	* @param {string} name
	* @returns {string\|null}
	*/
	function getCurrentValue(name) {
	try {
	return window.localStorage.getItem("rustdoc-" + name);
	} catch {
	return null;
	}
	}

	/**
	* Get a value from the rustdoc-vars div, which is used to convey data from
	* Rust to the JS. If there is no such element, return null.
	*
	* @param {string} name
	* @returns {string\|null}
	*/
	function getVar(name) {
	const el = document.querySelector("head > meta[name='rustdoc-vars']");
	return el ? el.getAttribute("data-" + name) : null;
	}

	/**
	* Change the current theme.
	* @param {string\|null} newThemeName
	* @param {boolean} saveTheme
	*/
	function switchTheme(newThemeName, saveTheme) {
	const themeNames = (getVar("themes") \|\| "").split(",").filter(t => t);
	themeNames.push(...builtinThemes);

	// Ensure that the new theme name is among the defined themes
	if (newThemeName === null \|\| themeNames.indexOf(newThemeName) === -1) {
	return;
	}

	// If this new value comes from a system setting or from the previously
	// saved theme, no need to save it.
	if (saveTheme) {
	updateLocalStorage("theme", newThemeName);
	}

	document.documentElement.setAttribute("data-theme", newThemeName);

	if (builtinThemes.indexOf(newThemeName) !== -1) {
	if (window.currentTheme && window.currentTheme.parentNode) {
	window.currentTheme.parentNode.removeChild(window.currentTheme);
	window.currentTheme = null;
	}
	} else {
	const newHref = getVar("root-path") + encodeURIComponent(newThemeName) +
	getVar("resource-suffix") + ".css";
	if (!window.currentTheme) {
	// If we're in the middle of loading, document.write blocks
	// rendering, but if we are done, it would blank the page.
	if (document.readyState === "loading") {
	document.write(`<link rel="stylesheet" id="themeStyle" href="${newHref}">`);
	window.currentTheme = (function() {
	const currentTheme = document.getElementById("themeStyle");
	return currentTheme instanceof HTMLLinkElement ? currentTheme : null;
	})();
	} else {
	window.currentTheme = document.createElement("link");
	window.currentTheme.rel = "stylesheet";
	window.currentTheme.id = "themeStyle";
	window.currentTheme.href = newHref;
	document.documentElement.appendChild(window.currentTheme);
	}
	} else if (newHref !== window.currentTheme.href) {
	window.currentTheme.href = newHref;
	}
	}
	}

	const updateTheme = (function() {
	// only listen to (prefers-color-scheme: dark) because light is the default
	const mql = window.matchMedia("(prefers-color-scheme: dark)");

	/**
	* Update the current theme to match whatever the current combination of
	* * the preference for using the system theme
	* (if this is the case, the value of preferred-light-theme, if the
	* system theme is light, otherwise if dark, the value of
	* preferred-dark-theme.)
	* * the preferred theme
	* … dictates that it should be.
	*/
	function updateTheme() {
	// maybe the user has disabled the setting in the meantime!
	if (getSettingValue("use-system-theme") !== "false") {
	const lightTheme = getSettingValue("preferred-light-theme") \|\| "light";
	const darkTheme = getSettingValue("preferred-dark-theme") \|\| "dark";
	updateLocalStorage("use-system-theme", "true");

	// use light theme if user prefers it, or has no preference
	switchTheme(mql.matches ? darkTheme : lightTheme, true);
	// note: we save the theme so that it doesn't suddenly change when
	// the user disables "use-system-theme" and reloads the page or
	// navigates to another page
	} else {
	switchTheme(getSettingValue("theme"), false);
	}
	}

	mql.addEventListener("change", updateTheme);

	return updateTheme;
	})();

	// @ts-ignore
	if (getSettingValue("use-system-theme") !== "false" && window.matchMedia) {
	// update the preferred dark theme if the user is already using a dark theme
	// See https://github.com/rust-lang/rust/pull/77809#issuecomment-707875732
	if (getSettingValue("use-system-theme") === null
	&& getSettingValue("preferred-dark-theme") === null
	&& localStoredTheme !== null
	&& darkThemes.indexOf(localStoredTheme) >= 0) {
	updateLocalStorage("preferred-dark-theme", localStoredTheme);
	}
	}

	updateTheme();

	// Hide, show, and resize the sidebar at page load time
	//
	// This needs to be done here because this JS is render-blocking,
	// so that the sidebar doesn't "jump" after appearing on screen.
	// The user interaction to change this is set up in main.js.
	//
	// At this point in page load, `document.body` is not available yet.
	// Set a class on the `<html>` element instead.
	if (getSettingValue("source-sidebar-show") === "true") {
	addClass(document.documentElement, "src-sidebar-expanded");
	}
	if (getSettingValue("hide-sidebar") === "true") {
	addClass(document.documentElement, "hide-sidebar");
	}
	if (getSettingValue("hide-toc") === "true") {
	addClass(document.documentElement, "hide-toc");
	}
	if (getSettingValue("hide-modnav") === "true") {
	addClass(document.documentElement, "hide-modnav");
	}
	if (getSettingValue("sans-serif-fonts") === "true") {
	addClass(document.documentElement, "sans-serif");
	}
	if (getSettingValue("word-wrap-source-code") === "true") {
	addClass(document.documentElement, "word-wrap-source-code");
	}
	function updateSidebarWidth() {
	const desktopSidebarWidth = getSettingValue("desktop-sidebar-width");
	if (desktopSidebarWidth && desktopSidebarWidth !== "null") {
	document.documentElement.style.setProperty(
	"--desktop-sidebar-width",
	desktopSidebarWidth + "px",
	);
	}
	const srcSidebarWidth = getSettingValue("src-sidebar-width");
	if (srcSidebarWidth && srcSidebarWidth !== "null") {
	document.documentElement.style.setProperty(
	"--src-sidebar-width",
	srcSidebarWidth + "px",
	);
	}
	}
	updateSidebarWidth();

	// If we navigate away (for example to a settings page), and then use the back or
	// forward button to get back to a page, the theme may have changed in the meantime.
	// But scripts may not be re-loaded in such a case due to the bfcache
	// (https://web.dev/bfcache/). The "pageshow" event triggers on such navigations.
	// Use that opportunity to update the theme.
	// We use a setTimeout with a 0 timeout here to put the change on the event queue.
	// For some reason, if we try to change the theme while the `pageshow` event is
	// running, it sometimes fails to take effect. The problem manifests on Chrome,
	// specifically when talking to a remote website with no caching.
	window.addEventListener("pageshow", ev => {
	if (ev.persisted) {
	setTimeout(updateTheme, 0);
	setTimeout(updateSidebarWidth, 0);
	}
	});

	// Custom elements are used to insert some JS-dependent features into Rustdoc,
	// because the [parser] runs the connected callback
	// synchronously. It needs to be added synchronously so that nothing below it
	// becomes visible until after it's done. Otherwise, you get layout jank.
	//
	// That's also why this is in storage.js and not main.js.
	//
	// [parser]: https://html.spec.whatwg.org/multipage/parsing.html
	class RustdocToolbarElement extends HTMLElement {
	constructor() {
	super();
	}
	connectedCallback() {
	// Avoid replacing the children after they're already here.
	if (this.firstElementChild) {
	return;
	}
	const rootPath = getVar("root-path");
	const currentUrl = window.location.href.split("?")[0].split("#")[0];
	this.innerHTML = `
	<div id="search-button" tabindex="-1">
	<a href="${currentUrl}?search="><span class="label">Search</span></a>
	</div>
	<div class="settings-menu" tabindex="-1">
	<a href="${rootPath}settings.html"><span class="label">Settings</span></a>
	</div>
	<div class="help-menu" tabindex="-1">
	<a href="${rootPath}help.html"><span class="label">Help</span></a>
	</div>
	<button id="toggle-all-docs"
	title="Collapse sections (shift-click to also collapse impl blocks)"><span
	class="label">Summary</span></button>`;
	}
	}
	window.customElements.define("rustdoc-toolbar", RustdocToolbarElement);
	class RustdocTopBarElement extends HTMLElement {
	constructor() {
	super();
	}
	connectedCallback() {
	const rootPath = getVar("root-path");
	const tmplt = document.createElement("template");
	tmplt.innerHTML = `
	<slot name="sidebar-menu-toggle"></slot>
	<slot></slot>
	<slot name="settings-menu"></slot>
	<slot name="help-menu"></slot>
	`;
	const shadow = this.attachShadow({ mode: "open" });
	shadow.appendChild(tmplt.content.cloneNode(true));
	this.innerHTML += `
	<button class="sidebar-menu-toggle" slot="sidebar-menu-toggle" title="show sidebar">
	</button>
	<div class="settings-menu" slot="settings-menu" tabindex="-1">
	<a href="${rootPath}settings.html"><span class="label">Settings</span></a>
	</div>
	<div class="help-menu" slot="help-menu" tabindex="-1">
	<a href="${rootPath}help.html"><span class="label">Help</span></a>
	</div>
	`;
	}
	}
	window.customElements.define("rustdoc-topbar", RustdocTopBarElement);