rizaldy.club/quartz/components/scripts/toc.inline.ts
Andrew 27a41abb62
feat(toc,explorer): add accessibility for toggle (#1327)
* Restore focus highlight on explorer toggle button.

Remove `unset: all` declaration causing `outline`
property to be unset. This allows the default
browser focus highlight to be shown.

* Fix semantics of expandable sections (explorer, toc).

This adds the appropriate aria attributes for the [disclosure pattern](https://www.w3.org/WAI/ARIA/apg/patterns/disclosure/examples/disclosure-image-description/#javascriptandcsssourcecode) and uses `visibility: hidden` to remove the hidden elements from the focus order without disrupting the animations. Further work is needed on the tree view nodes.

* Run prettier for SCSS files.
2024-08-08 18:07:47 -07:00

50 lines
1.6 KiB
TypeScript

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")
this.setAttribute(
"aria-expanded",
this.getAttribute("aria-expanded") === "true" ? "false" : "true",
)
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))
})