Rename docs component files to remove underscores

No longer needed with modern Kit filename conventions

src/routes/docs/2.0/TableOfContents.svelte

@@ -0,0 +1,130 @@
+<script lang="ts">
+  import { createRunWithCleanup } from "$lib/utils/run-with-cleanup";
+  import { onMount } from "svelte";
+  import TocItems, { type TocItem } from "./TocItems.svelte";
+
+  export let el: HTMLElement | null;
+  export let rootMargin = "0% 0% -80% 0%";
+
+  let runWithCleanup = createRunWithCleanup();
+  let activeId: string | undefined;
+  let items: TocItem[] = [];
+  let idToItem: { [id: string]: TocItem } = {};
+  let visibleIds = new Set<string>();
+
+  $: flatItems = flattenItems(items);
+
+  function offsetItemById(id: string, offset: number): TocItem | undefined {
+    let item = idToItem[id];
+    if (item) {
+      return flatItems[item.index + offset];
+    }
+  }
+
+  function computeActiveId() {
+    if (visibleIds.size === 0) {
+      activeId = undefined;
+      return;
+    }
+    activeId = Array.from(visibleIds)
+      .map((id) => idToItem[id]!)
+      .reduce((a, b) => (a.index < b.index ? a : b))?.id;
+  }
+
+  let observer: IntersectionObserver | null = null;
+  onMount(() => {
+    observer = new IntersectionObserver(
+      (entries) => {
+        entries.forEach((entry) => {
+          if (entry.isIntersecting) {
+            visibleIds.add(entry.target.id);
+            computeActiveId();
+          } else if (visibleIds.has(entry.target.id)) {
+            visibleIds.delete(entry.target.id);
+            if (visibleIds.size > 0) {
+              computeActiveId();
+            } else {
+              let scrollingDown =
+                entry.boundingClientRect.y < (entry.rootBounds?.y ?? 0);
+              // If scrolling down, this one should remain active: we're still in the contents of it
+              //  until we get to the next item below.
+              // If scrolling up, we should go to the previous item.
+              if (!scrollingDown) {
+                activeId = offsetItemById(entry.target.id, -1)?.id;
+              }
+            }
+          }
+        });
+      },
+      { rootMargin }
+    );
+  });
+
+  function generateItems(root: HTMLElement, ignoreH1 = true) {
+    let headings = Array.from(
+      root.querySelectorAll(`${ignoreH1 ? "" : "h1, "}h2, h3, h4, h5, h6`)
+    );
+    let newItems: TocItem[] = [];
+    let index = 0;
+    for (const heading of headings) {
+      let headingLevel = parseInt(heading.tagName[1]);
+      const newItem = {
+        headingLevel,
+        index: index++,
+        id: heading.id,
+        url: "#" + heading.id,
+        title: heading.textContent || "",
+      };
+      idToItem[newItem.id] = newItem;
+      let parentItems: TocItem[] = newItems;
+      while (
+        parentItems.length > 0 &&
+        parentItems[parentItems.length - 1].headingLevel < headingLevel
+      ) {
+        let child = parentItems[parentItems.length - 1];
+        child.items = child.items || [];
+        parentItems = child.items;
+      }
+      parentItems.push(newItem);
+    }
+    return newItems;
+  }
+
+  $: items = el ? generateItems(el) : [];
+
+  function flattenItems(itemList?: TocItem[]) {
+    let result: TocItem[] = [];
+    if (!itemList) {
+      return result;
+    }
+    for (let item of itemList) {
+      result = result.concat([item], flattenItems(item.items));
+    }
+    return result;
+  }
+
+  $: runWithCleanup(() => {
+    if (!observer) {
+      return;
+    }
+    let ids = flatItems.map((item) => item.id);
+    ids.forEach((id) => {
+      let element = document.getElementById(id);
+      if (element) {
+        observer!.observe(element);
+      }
+    });
+    return () => {
+      ids.forEach((id) => {
+        let element = document.getElementById(id);
+        if (element) {
+          observer!.unobserve(element);
+        }
+      });
+    };
+  }, "observer");
+</script>
+
+<nav>
+  <TocItems {items} {activeId} />
+</nav>