|
| 1 | +// Populate the sidebar |
| 2 | +// |
| 3 | +// This is a script, and not included directly in the page, to control the total size of the book. |
| 4 | +// The TOC contains an entry for each page, so if each page includes a copy of the TOC, |
| 5 | +// the total size of the page becomes O(n**2). |
| 6 | +class MDBookSidebarScrollbox extends HTMLElement { |
| 7 | + constructor() { |
| 8 | + super(); |
| 9 | + } |
| 10 | + connectedCallback() { |
| 11 | + this.innerHTML = '{{#toc}}{{/toc}}'; |
| 12 | + // Set the current, active page, and reveal it if it's hidden |
| 13 | + let current_page = document.location.href.toString().split("#")[0].split("?")[0]; |
| 14 | + if (current_page.endsWith("/")) { |
| 15 | + current_page += "index.html"; |
| 16 | + } |
| 17 | + var links = Array.prototype.slice.call(this.querySelectorAll("a")); |
| 18 | + var l = links.length; |
| 19 | + for (var i = 0; i < l; ++i) { |
| 20 | + var link = links[i]; |
| 21 | + var href = link.getAttribute("href"); |
| 22 | + if (href && !href.startsWith("#") && !/^(?:[a-z+]+:)?\/\//.test(href)) { |
| 23 | + link.href = path_to_root + href; |
| 24 | + } |
| 25 | + // The "index" page is supposed to alias the first chapter in the book. |
| 26 | + if (link.href === current_page || (i === 0 && path_to_root === "" && current_page.endsWith("/index.html"))) { |
| 27 | + link.classList.add("active"); |
| 28 | + |
| 29 | + var parent = link.parentElement; |
| 30 | + if (parent && parent.classList.contains("chapter-item")) { |
| 31 | + parent.classList.add("expanded"); |
| 32 | + } |
| 33 | + while (parent) { |
| 34 | + if (parent.tagName === "LI" && parent.previousElementSibling) { |
| 35 | + if (parent.previousElementSibling.classList.contains("chapter-item")) { |
| 36 | + parent.previousElementSibling.classList.add("expanded"); |
| 37 | + } |
| 38 | + } |
| 39 | + parent = parent.parentElement; |
| 40 | + } |
| 41 | + } |
| 42 | + } |
| 43 | + // Track and set sidebar scroll position |
| 44 | + this.addEventListener('click', function(e) { |
| 45 | + if (e.target.tagName === 'A') { |
| 46 | + sessionStorage.setItem('sidebar-scroll', this.scrollTop); |
| 47 | + } |
| 48 | + }, { passive: true }); |
| 49 | + var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll'); |
| 50 | + sessionStorage.removeItem('sidebar-scroll'); |
| 51 | + if (sidebarScrollTop) { |
| 52 | + // preserve sidebar scroll position when navigating via links within sidebar |
| 53 | + this.scrollTop = sidebarScrollTop; |
| 54 | + } else { |
| 55 | + // scroll sidebar to current active section when navigating via "next/previous chapter" buttons |
| 56 | + var activeSection = document.querySelector('#sidebar .active'); |
| 57 | + if (activeSection) { |
| 58 | + activeSection.scrollIntoView({ block: 'center' }); |
| 59 | + } |
| 60 | + } |
| 61 | + // Toggle buttons cxl |
| 62 | + var sidebarAnchorToggles = document.querySelectorAll('#sidebar a.toggle'); |
| 63 | + function toggleSection(ev) { |
| 64 | + ev.currentTarget.parentElement.classList.toggle('expanded'); |
| 65 | + if(ev.currentTarget.parentElement.childNodes.length > 1) { |
| 66 | + ev.preventDefault(); |
| 67 | + } |
| 68 | + } |
| 69 | + Array.from(sidebarAnchorToggles).forEach(function (el) { |
| 70 | + el.addEventListener('click', toggleSection); |
| 71 | + }); |
| 72 | + } |
| 73 | +} |
| 74 | +window.customElements.define("mdbook-sidebar-scrollbox", MDBookSidebarScrollbox); |
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