site/quartz/components/scripts/toc.inline.ts

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1.5 KiB
TypeScript
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2024-04-05 00:03:11 +00:00
const bufferPx = 150
const observer = new IntersectionObserver((entries) => {
for (const entry of entries) {
const slug = entry.target.id
const tocEntryElement = document.querySelector(`a[data-for="${slug}"]`)
const windowHeight = entry.rootBounds?.height
if (windowHeight && tocEntryElement) {
if (entry.boundingClientRect.y < windowHeight) {
tocEntryElement.classList.add("in-view")
} else {
tocEntryElement.classList.remove("in-view")
}
}
}
})
function toggleToc(this: HTMLElement) {
this.classList.toggle("collapsed")
const content = this.nextElementSibling as HTMLElement | undefined
if (!content) return
content.classList.toggle("collapsed")
content.style.maxHeight = content.style.maxHeight === "0px" ? content.scrollHeight + "px" : "0px"
}
function setupToc() {
const toc = document.getElementById("toc")
if (toc) {
const collapsed = toc.classList.contains("collapsed")
const content = toc.nextElementSibling as HTMLElement | undefined
if (!content) return
content.style.maxHeight = collapsed ? "0px" : content.scrollHeight + "px"
toc.addEventListener("click", toggleToc)
window.addCleanup(() => toc.removeEventListener("click", toggleToc))
}
}
window.addEventListener("resize", setupToc)
document.addEventListener("nav", () => {
setupToc()
// update toc entry highlighting
observer.disconnect()
const headers = document.querySelectorAll("h1[id], h2[id], h3[id], h4[id], h5[id], h6[id]")
headers.forEach((header) => observer.observe(header))
})