fix indexing causing main thread freeze, various polish

quartz/components/scripts/popover.inline.ts

@@ -19,69 +19,73 @@ export function normalizeRelativeURLs(
   )
 }
 
-document.addEventListener("nav", () => {
-  const links = [...document.getElementsByClassName("internal")] as HTMLLinkElement[]
-  const p = new DOMParser()
-  for (const link of links) {
-    link.addEventListener("mouseenter", async ({ clientX, clientY }) => {
-      async function setPosition(popoverElement: HTMLElement) {
-        const { x, y } = await computePosition(link, popoverElement, {
-          middleware: [
-            inline({ x: clientX, y: clientY }),
-            shift(),
-            flip()
-          ]
-        })
-        Object.assign(popoverElement.style, {
-          left: `${x}px`,
-          top: `${y}px`,
-        })
-      }
-
-      if (link.dataset.fetchedPopover === "true") {
-        return setPosition(link.lastChild as HTMLElement)
-      }
-
-      const thisUrl = new URL(document.location.href)
-      thisUrl.hash = ""
-      thisUrl.search = ""
-      const targetUrl = new URL(link.href)
-      const hash = targetUrl.hash
-      targetUrl.hash = ""
-      targetUrl.search = ""
-      // prevent hover of the same page
-      if (thisUrl.toString() === targetUrl.toString()) return
-
-      const contents = await fetch(`${targetUrl}`)
-        .then((res) => res.text())
-        .catch((err) => {
-          console.error(err)
-        })
-
-      if (!contents) return
-      const html = p.parseFromString(contents, "text/html")
-      normalizeRelativeURLs(html, targetUrl)
-      const elts = [...html.getElementsByClassName("popover-hint")]
-      if (elts.length === 0) return
-
-      const popoverElement = document.createElement("div")
-      popoverElement.classList.add("popover")
-      const popoverInner = document.createElement("div")
-      popoverInner.classList.add("popover-inner")
-      popoverElement.appendChild(popoverInner)
-      elts.forEach(elt => popoverInner.appendChild(elt))
-
-      setPosition(popoverElement)
-      link.appendChild(popoverElement)
-      link.dataset.fetchedPopover = "true"
-
-      if (hash !== "") {
-        const heading = popoverInner.querySelector(hash) as HTMLElement | null
-        if (heading) {
-          // leave ~12px of buffer when scrolling to a heading
-          popoverInner.scroll({ top: heading.offsetTop - 12, behavior: 'instant' })
-        }
-      }
+const p = new DOMParser()
+async function mouseEnterHandler(this: HTMLLinkElement, { clientX, clientY }: { clientX: number, clientY: number }) {
+  const link = this
+  async function setPosition(popoverElement: HTMLElement) {
+    const { x, y } = await computePosition(link, popoverElement, {
+      middleware: [
+        inline({ x: clientX, y: clientY }),
+        shift(),
+        flip()
+      ]
+    })
+    Object.assign(popoverElement.style, {
+      left: `${x}px`,
+      top: `${y}px`,
     })
   }
+
+  // dont refetch if there's already a popover
+  if ([...link.children].some(child => child.classList.contains("popover"))) {
+    return setPosition(link.lastChild as HTMLElement)
+  }
+
+  const thisUrl = new URL(document.location.href)
+  thisUrl.hash = ""
+  thisUrl.search = ""
+  const targetUrl = new URL(link.href)
+  const hash = targetUrl.hash
+  targetUrl.hash = ""
+  targetUrl.search = ""
+  // prevent hover of the same page
+  if (thisUrl.toString() === targetUrl.toString()) return
+
+  const contents = await fetch(`${targetUrl}`)
+    .then((res) => res.text())
+    .catch((err) => {
+      console.error(err)
+    })
+
+  if (!contents) return
+  const html = p.parseFromString(contents, "text/html")
+  normalizeRelativeURLs(html, targetUrl)
+  const elts = [...html.getElementsByClassName("popover-hint")]
+  if (elts.length === 0) return
+
+  const popoverElement = document.createElement("div")
+  popoverElement.classList.add("popover")
+  const popoverInner = document.createElement("div")
+  popoverInner.classList.add("popover-inner")
+  popoverElement.appendChild(popoverInner)
+  elts.forEach(elt => popoverInner.appendChild(elt))
+
+  setPosition(popoverElement)
+  link.appendChild(popoverElement)
+
+  if (hash !== "") {
+    const heading = popoverInner.querySelector(hash) as HTMLElement | null
+    if (heading) {
+      // leave ~12px of buffer when scrolling to a heading
+      popoverInner.scroll({ top: heading.offsetTop - 12, behavior: 'instant' })
+    }
+  }
+}
+
+document.addEventListener("nav", () => {
+  const links = [...document.getElementsByClassName("internal")] as HTMLLinkElement[]
+  for (const link of links) {
+    link.removeEventListener("mouseenter", mouseEnterHandler)
+    link.addEventListener("mouseenter", mouseEnterHandler)
+  }
 })