106 lines
2.9 KiB
TypeScript
106 lines
2.9 KiB
TypeScript
'use client';
|
|
|
|
import { useEffect, useState } from 'react';
|
|
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
|
|
import { faListUl, faCircle } from '@fortawesome/free-solid-svg-icons';
|
|
|
|
interface TocItem {
|
|
id: string;
|
|
text: string;
|
|
depth: number;
|
|
}
|
|
|
|
export function PostToc() {
|
|
const [items, setItems] = useState<TocItem[]>([]);
|
|
const [activeId, setActiveId] = useState<string | null>(null);
|
|
|
|
useEffect(() => {
|
|
const headings = Array.from(
|
|
document.querySelectorAll<HTMLElement>('article h2, article h3')
|
|
);
|
|
const mapped = headings
|
|
.filter((el) => el.id)
|
|
.map((el) => ({
|
|
id: el.id,
|
|
text: el.innerText,
|
|
depth: el.tagName === 'H3' ? 3 : 2
|
|
}));
|
|
setItems(mapped);
|
|
|
|
const observer = new IntersectionObserver(
|
|
(entries) => {
|
|
entries.forEach((entry) => {
|
|
if (entry.isIntersecting) {
|
|
const id = (entry.target as HTMLElement).id;
|
|
if (id) {
|
|
setActiveId(id);
|
|
}
|
|
}
|
|
});
|
|
},
|
|
{
|
|
// Trigger when heading is in upper 40% of viewport
|
|
rootMargin: '0px 0px -60% 0px',
|
|
threshold: 0.1
|
|
}
|
|
);
|
|
|
|
headings.forEach((el) => observer.observe(el));
|
|
|
|
return () => observer.disconnect();
|
|
}, []);
|
|
|
|
const handleClick = (id: string) => (event: React.MouseEvent<HTMLAnchorElement>) => {
|
|
event.preventDefault();
|
|
const el = document.getElementById(id);
|
|
if (!el) return;
|
|
|
|
el.scrollIntoView({
|
|
behavior: 'smooth',
|
|
block: 'start'
|
|
});
|
|
|
|
// Temporary highlight
|
|
el.classList.add('toc-target-highlight');
|
|
setTimeout(() => {
|
|
el.classList.remove('toc-target-highlight');
|
|
}, 700);
|
|
|
|
// Update hash without instant jump
|
|
if (history.replaceState) {
|
|
const url = new URL(window.location.href);
|
|
url.hash = id;
|
|
history.replaceState(null, '', url.toString());
|
|
}
|
|
};
|
|
|
|
if (items.length === 0) return null;
|
|
|
|
return (
|
|
<nav className="sticky top-20 text-xs text-slate-500 dark:text-slate-400">
|
|
<div className="mb-2 inline-flex items-center gap-2 font-semibold text-slate-700 dark:text-slate-200">
|
|
<FontAwesomeIcon icon={faListUl} className="h-3 w-3 text-slate-400" />
|
|
目錄
|
|
</div>
|
|
<ul className="space-y-1">
|
|
{items.map((item) => (
|
|
<li key={item.id} className={item.depth === 3 ? 'pl-3' : ''}>
|
|
<a
|
|
href={`#${item.id}`}
|
|
onClick={handleClick(item.id)}
|
|
className={`line-clamp-2 inline-flex items-center gap-2 hover:text-blue-600 dark:hover:text-blue-400 ${
|
|
item.id === activeId
|
|
? 'text-blue-600 dark:text-blue-400 font-semibold'
|
|
: ''
|
|
}`}
|
|
>
|
|
<FontAwesomeIcon icon={faCircle} className="h-1.5 w-1.5 text-slate-300" />
|
|
{item.text}
|
|
</a>
|
|
</li>
|
|
))}
|
|
</ul>
|
|
</nav>
|
|
);
|
|
}
|