// Populate the sidebar // // This is a script, and not included directly in the page, to control the total size of the book. // The TOC contains an entry for each page, so if each page includes a copy of the TOC, // the total size of the page becomes O(n**2). class MDBookSidebarScrollbox extends HTMLElement { constructor() { super(); } connectedCallback() { this.innerHTML = '

'; // Set the current, active page, and reveal it if it's hidden let current_page = document.location.href.toString(); if (current_page.endsWith("/")) { current_page += "index.html"; } var links = Array.prototype.slice.call(this.querySelectorAll("a")); var l = links.length; for (var i = 0; i < l; ++i) { var link = links[i]; var href = link.getAttribute("href"); if (href && !href.startsWith("#") && !/^(?:[a-z+]+:)?\/\//.test(href)) { link.href = path_to_root + href; } // The "index" page is supposed to alias the first chapter in the book. if (link.href === current_page || (i === 0 && path_to_root === "" && current_page.endsWith("/index.html"))) { link.classList.add("active"); var parent = link.parentElement; if (parent && parent.classList.contains("chapter-item")) { parent.classList.add("expanded"); } while (parent) { if (parent.tagName === "LI" && parent.previousElementSibling) { if (parent.previousElementSibling.classList.contains("chapter-item")) { parent.previousElementSibling.classList.add("expanded"); } } parent = parent.parentElement; } } } // Track and set sidebar scroll position this.addEventListener('click', function(e) { if (e.target.tagName === 'A') { sessionStorage.setItem('sidebar-scroll', this.scrollTop); } }, { passive: true }); var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll'); sessionStorage.removeItem('sidebar-scroll'); if (sidebarScrollTop) { // preserve sidebar scroll position when navigating via links within sidebar this.scrollTop = sidebarScrollTop; } else { // scroll sidebar to current active section when navigating via "next/previous chapter" buttons var activeSection = document.querySelector('#sidebar .active'); if (activeSection) { activeSection.scrollIntoView({ block: 'center' }); } } // Toggle buttons var sidebarAnchorToggles = document.querySelectorAll('#sidebar a.toggle'); function toggleSection(ev) { ev.currentTarget.parentElement.classList.toggle('expanded'); } Array.from(sidebarAnchorToggles).forEach(function (el) { el.addEventListener('click', toggleSection); }); } } window.customElements.define("mdbook-sidebar-scrollbox", MDBookSidebarScrollbox);