@@ -0,0 +1,101 @@ |
| 1 | +"use client"; |
| 2 | + |
| 3 | +import { useEffect, useState } from "react"; |
| 4 | +import { usePathname } from "next/navigation"; |
| 5 | + |
| 6 | +interface Heading { |
| 7 | + id: string; |
| 8 | + text: string; |
| 9 | + level: number; |
| 10 | +} |
| 11 | + |
| 12 | +export default function TableOfContents() { |
| 13 | + const [headings, setHeadings] = useState<Heading[]>([]); |
| 14 | + const [activeId, setActiveId] = useState<string>(""); |
| 15 | + const pathname = usePathname(); |
| 16 | + |
| 17 | + useEffect(() => { |
| 18 | + setHeadings([]); |
| 19 | + setActiveId(""); |
| 20 | + |
| 21 | + const timer = setTimeout(() => { |
| 22 | + const article = document.querySelector("article"); |
| 23 | + if (!article) return; |
| 24 | + |
| 25 | + const elements = article.querySelectorAll("h2, h3"); |
| 26 | + const items: Heading[] = []; |
| 27 | + |
| 28 | + elements.forEach((el) => { |
| 29 | + if (!el.id) { |
| 30 | + el.id = |
| 31 | + el.textContent |
| 32 | + ?.toLowerCase() |
| 33 | + .replace(/[^a-z0-9]+/g, "-") |
| 34 | + .replace(/(^-|-$)/g, "") || ""; |
| 35 | + } |
| 36 | + |
| 37 | + items.push({ |
| 38 | + id: el.id, |
| 39 | + text: el.textContent || "", |
| 40 | + level: el.tagName === "H2" ? 2 : 3, |
| 41 | + }); |
| 42 | + }); |
| 43 | + |
| 44 | + setHeadings(items); |
| 45 | + }, 100); |
| 46 | + |
| 47 | + return () => clearTimeout(timer); |
| 48 | + }, [pathname]); |
| 49 | + |
| 50 | + useEffect(() => { |
| 51 | + if (headings.length === 0) return; |
| 52 | + |
| 53 | + const observer = new IntersectionObserver( |
| 54 | + (entries) => { |
| 55 | + entries.forEach((entry) => { |
| 56 | + if (entry.isIntersecting) { |
| 57 | + setActiveId(entry.target.id); |
| 58 | + } |
| 59 | + }); |
| 60 | + }, |
| 61 | + { rootMargin: "-80px 0px -80% 0px" } |
| 62 | + ); |
| 63 | + |
| 64 | + headings.forEach((heading) => { |
| 65 | + const el = document.getElementById(heading.id); |
| 66 | + if (el) observer.observe(el); |
| 67 | + }); |
| 68 | + |
| 69 | + return () => observer.disconnect(); |
| 70 | + }, [headings]); |
| 71 | + |
| 72 | + if (headings.length === 0) return null; |
| 73 | + |
| 74 | + return ( |
| 75 | + <nav className="w-56 shrink-0 hidden xl:block"> |
| 76 | + <div className="sticky top-8 p-4"> |
| 77 | + <h4 className="text-sm font-semibold text-surface-900 dark:text-surface-100 mb-4"> |
| 78 | + On This Page |
| 79 | + </h4> |
| 80 | + <ul className="space-y-2 text-sm"> |
| 81 | + {headings.map((heading) => ( |
| 82 | + <li key={heading.id}> |
| 83 | + <a |
| 84 | + href={`#${heading.id}`} |
| 85 | + className={`block transition-colors ${ |
| 86 | + heading.level === 3 ? "pl-3" : "" |
| 87 | + } ${ |
| 88 | + activeId === heading.id |
| 89 | + ? "text-surface-900 dark:text-surface-100 font-medium" |
| 90 | + : "text-surface-500 dark:text-surface-400 hover:text-surface-900 dark:hover:text-surface-100" |
| 91 | + }`} |
| 92 | + > |
| 93 | + {heading.text} |
| 94 | + </a> |
| 95 | + </li> |
| 96 | + ))} |
| 97 | + </ul> |
| 98 | + </div> |
| 99 | + </nav> |
| 100 | + ); |
| 101 | +} |
