// storage.js is loaded in the `` 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";
*/
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;
})();
/**
* 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} 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 (e) {
// 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 (e) {
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(``);
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 `` 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 RustdocSearchElement extends HTMLElement {
constructor() {
super();
}
connectedCallback() {
const rootPath = getVar("root-path");
const currentCrate = getVar("current-crate");
this.innerHTML = ``;
}
}
window.customElements.define("rustdoc-search", RustdocSearchElement);
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");
this.innerHTML = `