EtienneLescot · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026
@@ -86,12 +86,14 @@ function clip(startSec: number, endSec: number) {
  *  which is what the Full Camera button is gated on. */
 const NO_CAMERA_ASSET = { id: "a1", label: "rec", durationSec: TOTAL_SEC };
 
-/** By default one 30-minute clip carrying a single one-second annotation. */
+/** By default one 30-minute clip carrying a single one-second annotation, and a store that
+ *  holds an edit region (so Clear timeline shows); `overrides` replaces any `tl` member. */
 function renderTimeline(
 	clips = [clip(0, TOTAL_SEC)],
 	annotation = { id: "ann1", startMs: 10_000, endMs: 11_000 },
 	assets: Array<Record<string, unknown>> = [NO_CAMERA_ASSET],
 	onRender?: ProfilerOnRenderCallback,
+	overrides: Record<string, unknown> = {},
 ) {
 	const tl = {
 		clips,
@@ -104,6 +106,8 @@ function renderTimeline(
 		cameraFullscreenRegions: [],
 		zoomRegions: [],
 		trimRanges: [],
+		hasEditRegions: true,
+		...overrides,
 		selection: null,
 		multiSelection: [],
 		clipSelection: null,
@@ -119,6 +123,9 @@ function renderTimeline(
 		addZoom: vi.fn(async () => {
 			/* the toolbar only awaits it */
 		}),
+		clearTimeline: vi.fn(async () => {
+			/* the toolbar only awaits it */
+		}),
 	};
 	const setCurrentTime = vi.fn();
 	const timeline = (
@@ -145,7 +152,11 @@ function renderTimeline(
 		),
 	);
 	return {
-		pill: screen.getByTitle("toolbar.newAnnotation"),
+		// A getter: a test that empties `annotationRegions` renders no such pill, and an eager
+		// lookup would throw before its own assertions ran.
+		get pill() {
+			return screen.getByTitle("toolbar.newAnnotation");
+		},
 		clipEls: Array.from(document.querySelectorAll<HTMLElement>("[data-clip-id]")),
 		tl,
 		setCurrentTime,
@@ -403,6 +414,46 @@ describe("V4Timeline create-from-toolbar", () => {
 		expect(durationOf(tl)).toBeCloseTo(0.25, 3);
 	});
 
+	// Clear timeline (#723) follows the STORED edit regions (`tl.hasEditRegions`), never the
+	// pills the lanes draw: a trim whose clip is gone is stored, cleared, and has no pill.
+	// Absent, never greyed out, when there is nothing to clear.
+	const toolbarOf = () => screen.getByRole("toolbar", { name: "toolbar.timelineTools" });
+	const dividersIn = (toolbar: HTMLElement) =>
+		Array.from(toolbar.querySelectorAll("[class*=tlToolSep]"));
+
+	it("shows no Clear timeline button while the store holds no edit region, and no divider for it", () => {
+		// A pill is drawn, and the button still follows the store.
+		renderTimeline(undefined, undefined, undefined, undefined, { hasEditRegions: false });
+		expect(screen.queryByLabelText("buttons.clearTimeline")).not.toBeInTheDocument();
+		// Only the divider after the auto-enhance button: none is left dangling at the end.
+		expect(dividersIn(toolbarOf())).toHaveLength(1);
+	});
+
+	it("shows it for a stored region no lane draws, and one click asks the store to clear", () => {
+		const { tl } = renderTimeline(undefined, undefined, undefined, undefined, {
+			annotationRegions: [],
+			hasEditRegions: true,
+		});
+		expect(document.querySelector("[class*=lanePill]")).toBeNull();
+		fireEvent.click(screen.getByLabelText("buttons.clearTimeline"));
+		expect(tl.clearTimeline).toHaveBeenCalledTimes(1);
+	});
+
+	it("puts Clear timeline last, behind a divider, after the Add Full Camera button", () => {
+		renderTimeline();
+		const toolbar = toolbarOf();
+		const buttons = Array.from(toolbar.querySelectorAll("button"));
+		const clear = screen.getByLabelText("buttons.clearTimeline");
+		expect(buttons.at(-1)).toBe(clear);
+
+		const divider = clear.previousElementSibling;
+		expect(divider?.className).toContain("tlToolSep");
+		expect(divider?.previousElementSibling).toBe(
+			screen.getByLabelText("buttons.addCameraFullscreen"),
+		);
+		expect(dividersIn(toolbar)).toHaveLength(2);
+	});
+
 	// #353. A camera-fullscreen region grows the webcam overlay, so with no webcam on the
 	// timeline it renders nothing in the preview and nothing in the export — the region is
 	// stored and forgotten. `addCameraFullscreen` now refuses to write one; the button says

@@ -2,6 +2,7 @@ import {
 	AudioLines,
 	Clock,
 	Crosshair,
+	Eraser,
 	Loader2,
 	Maximize2,
 	MessageSquare,
@@ -1998,6 +1999,25 @@ export function V4Timeline({
 									<Maximize2 size={16} />
 								</button>
 							</Tooltip>
+							{/* Last, behind a divider: every button before it adds a region, this one
+							    clears them. Absent with its divider, not greyed out, when there is
+							    nothing to clear. One write in the store, so one Ctrl+Z restores every
+							    region. */}
+							{tl.hasEditRegions ? (
+								<>
+									<span className={styles.tlToolSep} aria-hidden />
+									<Tooltip content={t("buttons.clearTimeline")}>
+										<button
+											type="button"
+											className={styles.tlToolBtn}
+											aria-label={t("buttons.clearTimeline")}
+											onClick={() => void tl.clearTimeline()}
+										>
+											<Eraser size={16} />
+										</button>
+									</Tooltip>
+								</>
+							) : null}
 						</div>
 					</TooltipProvider>
 				) : (

@@ -6,6 +6,7 @@
 		"autoZoomOff": "اقتراحات التكبير التلقائي معطّلة — انقر لاقتراح تكبيرات من المؤشر",
 		"autoFocusAllOn": "التركيز التلقائي مفعّل لجميع التكبيرات — انقر للتبديل إلى يدوي للجميع",
 		"autoFocusAllOff": "تفعيل التركيز التلقائي لجميع التكبيرات (الكاميرا تتبع المؤشر)",
+		"clearTimeline": "مسح المخطط الزمني",
 		"addTrim": "إضافة قص (T)",
 		"addAnnotation": "إضافة شرح (A)",
 		"addSpeed": "إضافة سرعة (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Automatické návrhy přiblížení vypnuty, klikněte pro návrh přiblížení podle kurzoru",
 		"autoFocusAllOn": "Automatické zaostření zapnuto pro všechna přiblížení, klikněte pro přepnutí všech na ruční",
 		"autoFocusAllOff": "Automaticky zaostřit všechna přiblížení (kamera sleduje kurzor)",
+		"clearTimeline": "Vymazat časovou osu",
 		"addTrim": "Přidat oříznutí (T)",
 		"addAnnotation": "Přidat anotaci (A)",
 		"addSpeed": "Přidat rychlost (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Zoom-Vorschläge aus — klicken, um Zooms aus der Cursorbewegung vorzuschlagen",
 		"autoFocusAllOn": "Auto-Fokus für alle Zooms an — klicken, um alle auf manuell umzustellen",
 		"autoFocusAllOff": "Auto-Fokus für alle Zooms (Kamera folgt dem Cursor)",
+		"clearTimeline": "Timeline leeren",
 		"addTrim": "Trim hinzufügen (T)",
 		"addAnnotation": "Anmerkung hinzufügen (A)",
 		"addSpeed": "Tempo hinzufügen (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Auto zoom suggestions off — click to suggest zooms from cursor",
 		"autoFocusAllOn": "Auto-Focus on for all zooms — click to switch all to manual",
 		"autoFocusAllOff": "Auto-Focus all zooms (camera follows the cursor)",
+		"clearTimeline": "Clear timeline",
 		"addTrim": "Add trim (T)",
 		"addAnnotation": "Add annotation (A)",
 		"addSpeed": "Add speed (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Sugerencias de zoom automático desactivadas — haz clic para sugerir zooms desde el cursor",
 		"autoFocusAllOn": "Enfoque automático activado para todos los zooms — haz clic para pasar todos a manual",
 		"autoFocusAllOff": "Activar enfoque automático para todos los zooms (la cámara sigue el cursor)",
+		"clearTimeline": "Borrar la línea de tiempo",
 		"addTrim": "Agregar recorte (T)",
 		"addAnnotation": "Agregar anotación (A)",
 		"addSpeed": "Agregar velocidad (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Suggestions de zoom automatique désactivées — cliquez pour suggérer des zooms depuis le curseur",
 		"autoFocusAllOn": "Mise au point automatique activée pour tous les zooms — cliquez pour tout passer en manuel",
 		"autoFocusAllOff": "Activer la mise au point automatique pour tous les zooms (la caméra suit le curseur)",
+		"clearTimeline": "Effacer la timeline",
 		"addTrim": "Ajouter une coupe (T)",
 		"addAnnotation": "Ajouter une annotation (A)",
 		"addSpeed": "Ajouter une vitesse (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Suggerimenti di zoom automatico disattivi — clicca per suggerire zoom dal cursore",
 		"autoFocusAllOn": "Messa a fuoco automatica attiva per tutti gli zoom — clicca per passare tutti a manuale",
 		"autoFocusAllOff": "Attiva la messa a fuoco automatica per tutti gli zoom (la fotocamera segue il cursore)",
+		"clearTimeline": "Cancella la timeline",
 		"addTrim": "Aggiungi taglio (T)",
 		"addAnnotation": "Aggiungi annotazione (A)",
 		"addSpeed": "Aggiungi velocità (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "自動ズーム提案がオフ — クリックするとカーソル位置からズームを提案します",
 		"autoFocusAllOn": "すべてのズームでオートフォーカスがオン — クリックするとすべて手動に切り替わります",
 		"autoFocusAllOff": "すべてのズームでオートフォーカスをオンにする（カメラがカーソルに追従）",
+		"clearTimeline": "タイムラインをクリア",
 		"addTrim": "トリムを追加 (T)",
 		"addAnnotation": "注釈を追加 (A)",
 		"addSpeed": "再生速度を追加 (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "자동 줌 제안 꺼짐 — 클릭하면 커서 기반으로 줌을 제안합니다",
 		"autoFocusAllOn": "모든 줌에 자동 초점 켜짐 — 클릭하면 모두 수동으로 전환합니다",
 		"autoFocusAllOff": "모든 줌에 자동 초점 켜기 (카메라가 커서를 따라갑니다)",
+		"clearTimeline": "타임라인 지우기",
 		"addTrim": "트림 추가 (T)",
 		"addAnnotation": "주석 추가 (A)",
 		"addSpeed": "속도 추가 (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Sugestões de zoom automático desativadas — clique para sugerir zooms a partir do cursor",
 		"autoFocusAllOn": "Foco automático ativado para todos os zooms — clique para mudar todos para manual",
 		"autoFocusAllOff": "Ativar foco automático para todos os zooms (a câmera segue o cursor)",
+		"clearTimeline": "Limpar a linha do tempo",
 		"addTrim": "Adicionar Recorte (T)",
 		"addAnnotation": "Adicionar Anotação (A)",
 		"addSpeed": "Adicionar Velocidade (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Автоматические предложения масштабирования выключены — нажмите, чтобы предложить зумы по курсору",
 		"autoFocusAllOn": "Автофокус включён для всех зумов — нажмите, чтобы переключить все в ручной режим",
 		"autoFocusAllOff": "Включить автофокус для всех зумов (камера следует за курсором)",
+		"clearTimeline": "Очистить таймлайн",
 		"addTrim": "Добавить обрезку (T)",
 		"addAnnotation": "Добавить аннотацию (A)",
 		"addSpeed": "Изменить скорость (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Otomatik yakınlaştırma önerileri kapalı — imleçten yakınlaştırma önermek için tıklayın",
 		"autoFocusAllOn": "Tüm yakınlaştırmalarda Otomatik Odak açık — hepsini manuel yapmak için tıklayın",
 		"autoFocusAllOff": "Tüm yakınlaştırmalarda Otomatik Odağı aç (kamera imleci takip eder)",
+		"clearTimeline": "Zaman çizelgesini temizle",
 		"addTrim": "Kırpma Ekle (T)",
 		"addAnnotation": "Açıklama Ekle (A)",
 		"addSpeed": "Hız Ekle (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "Đề xuất thu phóng tự động đang tắt — nhấp để đề xuất thu phóng từ con trỏ",
 		"autoFocusAllOn": "Lấy nét tự động đang bật cho tất cả các thu phóng — nhấp để chuyển tất cả sang thủ công",
 		"autoFocusAllOff": "Bật lấy nét tự động cho tất cả các thu phóng (máy ảnh theo dõi con trỏ)",
+		"clearTimeline": "Xóa dòng thời gian",
 		"addTrim": "Thêm Cắt (T)",
 		"addAnnotation": "Thêm Chú thích (A)",
 		"addSpeed": "Thêm Tốc độ (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "自动缩放建议已关闭 — 点击可根据光标建议缩放",
 		"autoFocusAllOn": "所有缩放的自动对焦已开启 — 点击可将全部切换为手动",
 		"autoFocusAllOff": "为所有缩放开启自动对焦（摄像头跟随光标）",
+		"clearTimeline": "清除时间轴",
 		"addTrim": "添加剪辑 (T)",
 		"addAnnotation": "添加标注 (A)",
 		"addSpeed": "添加速度 (S)",

@@ -6,6 +6,7 @@
 		"autoZoomOff": "自動縮放建議已關閉 — 點擊可根據游標建議縮放",
 		"autoFocusAllOn": "所有縮放的自動對焦已開啟 — 點擊可將全部切換為手動",
 		"autoFocusAllOff": "為所有縮放開啟自動對焦（攝影機跟隨游標）",
+		"clearTimeline": "清除時間軸",
 		"addTrim": "新增剪輯 (T)",
 		"addAnnotation": "新增標註 (A)",
 		"addSpeed": "新增速度 (S)",

@@ -1129,6 +1129,53 @@ export function removeRegion(document: AxcutDocument, kind: RegionKind, id: stri
 	}
 }
 
+const legacyRegionCount = (document: AxcutDocument, key: string): number => {
+	const stored = (document.legacyEditor as Record<string, unknown> | null)?.[key];
+	return Array.isArray(stored) ? stored.length : 0;
+};
+const withLegacyRegionsCleared = (document: AxcutDocument, key: string): AxcutDocument =>
+	document.legacyEditor
+		? { ...document, legacyEditor: { ...document.legacyEditor, [key]: [] } }
+		: document;
+
+/**
+ * The edit regions "Clear timeline" empties: one entry per `RegionKind` but `audio`. A Record
+ * rather than a list, so a new kind is a compile error here until someone decides whether it
+ * is an edit. `audio` is deliberately absent, like everything that is not a region at all:
+ * clips, media, transcripts, captions and the pauses added words made are content the user
+ * put there on purpose. (`timeline.speedRanges` is not the speed lane's store; the lane and
+ * the export read `legacyEditor.speedRegions`.)
+ */
+const EDIT_REGIONS: Record<
+	Exclude<RegionKind, "audio">,
+	{ count: (d: AxcutDocument) => number; clear: (d: AxcutDocument) => AxcutDocument }
+> = {
+	zoom: { count: (d) => d.zoomRanges.length, clear: (d) => ({ ...d, zoomRanges: [] }) },
+	annotation: { count: (d) => d.annotations.length, clear: (d) => ({ ...d, annotations: [] }) },
+	trim: {
+		count: (d) => d.timeline.trimRanges.length,
+		clear: (d) => ({ ...d, timeline: { ...d.timeline, trimRanges: [] } }),
+	},
+	speed: {
+		count: (d) => legacyRegionCount(d, "speedRegions"),
+		clear: (d) => withLegacyRegionsCleared(d, "speedRegions"),
+	},
+	cameraFullscreen: {
+		count: (d) => legacyRegionCount(d, "cameraFullscreenRegions"),
+		clear: (d) => withLegacyRegionsCleared(d, "cameraFullscreenRegions"),
+	},
+};
+
+/** How many edit regions the document holds, stored rows and not pills. Pure. */
+export function countEditRegions(document: AxcutDocument): number {
+	return Object.values(EDIT_REGIONS).reduce((sum, kind) => sum + kind.count(document), 0);
+}
+
+/** The document with every edit region gone (see {@link EDIT_REGIONS}). Pure. */
+export function clearEditRegions(document: AxcutDocument): AxcutDocument {
+	return Object.values(EDIT_REGIONS).reduce((doc, kind) => kind.clear(doc), document);
+}
+
 /**
  * The document, with its clip list changed to this one.
  *

@@ -254,6 +254,8 @@ const DECLARED: WritePath[] = [
 	w("src/lib/ai-edition/store/useTimeline.ts", "addTrim", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "addZoom", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "addZoomsBulk", "save", "gesture"),
+	// The Clear timeline button: every edit region in one write, so one undo step.
+	w("src/lib/ai-edition/store/useTimeline.ts", "clearTimeline", "save", "gesture"),
 	// The two drag commits. One undo step per gesture, recorded on release and only
 	// if the write lands — `historyBase` carries the pre-drag document.
 	w("src/lib/ai-edition/store/useTimeline.ts", "commitAnnotationChange", "save", "gesture"),