feat(chapters): focus the title field when adding a chapter

src/components/EditorView.tsx

@@ -37,6 +37,8 @@ export function EditorView() {
   const setChapterContent = useBook((s) => s.setChapterContent);
   const setChapterTitle = useBook((s) => s.setChapterTitle);
   const setChapterNoTitle = useBook((s) => s.setChapterNoTitle);
+  const pendingTitleFocus = useBook((s) => s.pendingTitleFocus);
+  const clearTitleFocus = useBook((s) => s.clearTitleFocus);
   const markSaved = useBook((s) => s.markSaved);
   const theme = useTheme((s) => s.theme);
   const toggleTheme = useTheme((s) => s.toggle);
@@ -88,6 +90,7 @@ export function EditorView() {
   }, []);
 
   const focusEditorSoon = useCallback(() => {
+    if (useBook.getState().pendingTitleFocus) return;
     requestAnimationFrame(() => editorRef.current?.commands.focus(undefined, { scrollIntoView: false }));
   }, []);
 
@@ -420,6 +423,8 @@ export function EditorView() {
                   chapter.noTitle ? "No title" : kind === "body" ? "Chapter title" : kind === "part" ? "Part title (optional)" : "Page title"
                 }
                 disabled={!!chapter.noTitle}
+                focusRequest={pendingTitleFocus === chapter.id}
+                onFocused={clearTitleFocus}
                 onChange={(value) => setChapterTitle(chapter.id, value)}
               />
               {(chapter.noTitle || !chapter.title.trim()) && (
@@ -495,11 +500,15 @@ function ChapterTitleInput({
   value,
   placeholder,
   disabled,
+  focusRequest,
+  onFocused,
   onChange,
 }: {
   value: string;
   placeholder: string;
   disabled: boolean;
+  focusRequest: boolean;
+  onFocused: () => void;
   onChange: (value: string) => void;
 }) {
   const ref = useRef<HTMLTextAreaElement>(null);
@@ -511,6 +520,15 @@ function ChapterTitleInput({
     el.style.height = `${el.scrollHeight}px`;
   }, [value, disabled]);
 
+  useEffect(() => {
+    if (!focusRequest || disabled) return;
+    const el = ref.current;
+    if (!el) return;
+    el.focus();
+    el.select();
+    onFocused();
+  }, [focusRequest, disabled, onFocused]);
+
   return (
     <textarea
       ref={ref}

src/components/Sidebar.tsx

@@ -260,7 +260,13 @@ export function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
                 )}
               </ul>
               {group.kind === "body" && (
-                <button className="add-chapter" onClick={addChapter}>
+                <button
+                  className="add-chapter"
+                  onClick={() => {
+                    addChapter();
+                    onNavigate?.();
+                  }}
+                >
                   <Icon d="M12 5v14M5 12h14" />
                   New chapter
                 </button>

src/store/useBook.ts

@@ -25,6 +25,8 @@ interface BookState {
   dirty: boolean;
   exporting: string | null;
   notice: string | null;
+  pendingTitleFocus: string | null;
+  clearTitleFocus: () => void;
   setExporting: (label: string | null) => void;
   setNotice: (message: string | null) => void;
   openBook: (book: Book) => void;
@@ -57,6 +59,8 @@ export const useBook = create<BookState>((set, get) => ({
   dirty: false,
   exporting: null,
   notice: null,
+  pendingTitleFocus: null,
+  clearTitleFocus: () => set({ pendingTitleFocus: null }),
   setExporting: (label) => set({ exporting: label }),
   setNotice: (message) => set({ notice: message }),
   openBook: (book) => {
@@ -66,14 +70,14 @@ export const useBook = create<BookState>((set, get) => ({
     const valid = saved === COVER_ID || normalized.chapters.some((c) => c.id === saved);
     const activeChapterId = valid ? (saved as string) : normalized.chapters[0]?.id ?? "";
     applyBookFonts(normalized.settings.fonts);
-    set({ book: normalized, activeChapterId, dirty: false });
+    set({ book: normalized, activeChapterId, dirty: false, pendingTitleFocus: null });
   },
   closeBook: () => {
     flushOutgoing(get().book, get().dirty);
     resetBookFonts();
-    set({ book: null, activeChapterId: "", dirty: false });
+    set({ book: null, activeChapterId: "", dirty: false, pendingTitleFocus: null });
   },
-  setActiveChapter: (id) => set({ activeChapterId: id }),
+  setActiveChapter: (id) => set({ activeChapterId: id, pendingTitleFocus: null }),
   goToAdjacentChapter: (dir) => {
     const { book, activeChapterId } = get();
     if (!book) return;
@@ -81,7 +85,7 @@ export const useBook = create<BookState>((set, get) => ({
     const i = ids.indexOf(activeChapterId);
     if (i === -1) return;
     const next = ids[(i + dir + ids.length) % ids.length];
-    if (next !== activeChapterId) set({ activeChapterId: next });
+    if (next !== activeChapterId) set({ activeChapterId: next, pendingTitleFocus: null });
   },
   setChapterContent: (id, content) =>
     set((s) =>
@@ -110,11 +114,16 @@ export const useBook = create<BookState>((set, get) => ({
   addChapter: () =>
     set((s) => {
       if (!s.book) return {};
-      const chapter = createChapter();
+      const chapter = createChapter("");
       const chapters = [...s.book.chapters];
       const backCount = chapters.filter((c) => chapterKind(c) === "back").length;
       chapters.splice(chapters.length - backCount, 0, chapter);
-      return { activeChapterId: chapter.id, dirty: true, book: { ...s.book, chapters } };
+      return {
+        activeChapterId: chapter.id,
+        pendingTitleFocus: chapter.id,
+        dirty: true,
+        book: { ...s.book, chapters },
+      };
     }),
   addPage: (group, title) =>
     set((s) => {