Storyline: unfoldable section list per chapter in the sidebar

Each chapter in the right-hand menu gets a caret that unfolds its numbered sections (e.g. the prologue's 28 scenes); clicking one jumps straight to it. The chapter you're reading starts unfolded, other chapters' sections link across (/storyline/overview#section-…), and the section at the top of the pane is highlighted as you scroll. - ChapterOutline service parses each rendered chapter for its <h2 class="storyline-section"> headings, adds anchor ids and returns the outline; the controller renders all chapters once to feed the sidebar. - storyline-toc Stimulus controller: fold/unfold, in-pane jump, scroll-spy (works in the split view and in the small-screen window-scroll fallback). - Tests for the outline parser. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-21 18:44:54 +02:00
parent 8b8f67c1d0
commit b77e5eaa4f
6 changed files with 229 additions and 8 deletions
@@ -0,0 +1,72 @@
+import { Controller } from '@hotwired/stimulus';
+
+/*
+ * Sidebar table of contents on a storyline chapter page.
+ *
+ *  - the caret unfolds/folds a chapter's section list
+ *  - links for the chapter being read (target "link", href="#section-…")
+ *    jump inside the split view's scrolling pane
+ *  - the section currently at the top of the pane is highlighted
+ */
+export default class extends Controller {
+    static targets = ['link'];
+
+    connect() {
+        this.pane = this.element.closest('.storyline-split-main');
+        this.onScroll = () => {
+            if (this.frame) return;
+            this.frame = requestAnimationFrame(() => {
+                this.frame = null;
+                this.highlight();
+            });
+        };
+        (this.pane || window).addEventListener('scroll', this.onScroll, { passive: true });
+        window.addEventListener('scroll', this.onScroll, { passive: true });
+        this.highlight();
+    }
+
+    disconnect() {
+        (this.pane || window).removeEventListener('scroll', this.onScroll);
+        window.removeEventListener('scroll', this.onScroll);
+    }
+
+    fold(event) {
+        const item = event.currentTarget.closest('.storyline-toc-item');
+        const open = item.classList.toggle('is-open');
+        event.currentTarget.setAttribute('aria-expanded', open ? 'true' : 'false');
+    }
+
+    jump(event) {
+        const id = event.currentTarget.getAttribute('href').slice(1);
+        const el = document.getElementById(id);
+        if (!el) return;
+        event.preventDefault();
+        el.scrollIntoView({ block: 'start' });
+        history.replaceState(null, '', `#${id}`);
+    }
+
+    linkTargetConnected(link) {
+        link.addEventListener('click', (e) => this.jump({ currentTarget: link, preventDefault: () => e.preventDefault() }));
+    }
+
+    highlight() {
+        if (!this.hasLinkTarget) return;
+        // In the split view the pane scrolls; on small screens the window does.
+        const paneScrolls = this.pane && getComputedStyle(this.pane).overflowY !== 'visible';
+        const top = paneScrolls ? this.pane.getBoundingClientRect().top : 0;
+        let current = null;
+        for (const link of this.linkTargets) {
+            const el = document.getElementById(link.getAttribute('href').slice(1));
+            if (el && el.getBoundingClientRect().top - top <= 90) current = link;
+        }
+        this.linkTargets.forEach((l) => l.classList.toggle('is-current', l === current));
+        if (current && this.pane) {
+            const list = current.closest('.storyline-toc-sections');
+            if (list && list.scrollHeight > list.clientHeight) {
+                const c = current.getBoundingClientRect();
+                const l = list.getBoundingClientRect();
+                if (c.top < l.top || c.bottom > l.bottom) current.scrollIntoView({ block: 'nearest' });
+            }
+        }
+    }
+}