feat(studio): export player handle for hosts (#4227)

packages/studio/src/components/nle/NLEContext.tsx

@@ -1,7 +1,7 @@
 import { buildProjectApiPath } from "../../utils/projectRouting";
 import { useContext, useState, useCallback, useRef, useEffect, type ReactNode } from "react";
-import { useTimelinePlayer, usePlayerStore } from "../../player";
-import type { TimelineElement } from "../../player";
+import { useTimelinePlayer } from "../../player/hooks/useTimelinePlayer";
+import { usePlayerStore, type TimelineElement } from "../../player/store/playerStore";
 import type { PreviewIframeSlot } from "../../player/hooks/useTimelineSyncCallbacks";
 import type { CompositionLevel } from "./CompositionBreadcrumb";
 import { useCompositionStack } from "./useCompositionStack";
@@ -18,6 +18,8 @@ export interface NLEContextValue {
   projectId: string;
   // player (from useTimelinePlayer — single instance for the whole shell)
   iframeRef: React.MutableRefObject<HTMLIFrameElement | null>;
+  play: () => void;
+  pause: () => void;
   togglePlay: () => void;
   seek: (time: number, options?: { keepPlaying?: boolean }) => boolean;
   refreshPlayer: () => void;
@@ -84,6 +86,8 @@ export function NLEProvider({
   const containerRef = useRef<HTMLDivElement>(null);
   const {
     iframeRef,
+    play,
+    pause,
     togglePlay,
     seek,
     onIframeLoad: baseOnIframeLoad,
@@ -298,6 +302,8 @@ export function NLEProvider({
   const value: NLEContextValue = {
     projectId,
     iframeRef,
+    play,
+    pause,
     containerRef,
     togglePlay,
     seek,

packages/studio/src/components/nle/useCompositionStack.ts

@@ -1,7 +1,7 @@
 import { buildProjectApiPath } from "../../utils/projectRouting";
 // Composition drill-down stack management for NLEContext/EditorShell
 import { useState, useCallback, useRef, useEffect } from "react";
-import { usePlayerStore } from "../../player";
+import { usePlayerStore } from "../../player/store/playerStore";
 import type { CompositionLevel } from "./CompositionBreadcrumb";
 import { encodePreviewPath } from "../../player/components/thumbnailUtils";
 

packages/studio/src/index.ts

@@ -46,12 +46,20 @@ export {
   VideoThumbnail,
   CompositionThumbnail,
   useTimelinePlayer,
+  usePlayerHandle,
   resolveIframe,
   usePlayerStore,
   liveTime,
   formatTime,
 } from "./player";
-export type { TimelineElement, TimelineTimeRange } from "./player";
+export type {
+  PlayerHandle,
+  PlayerHandleElement,
+  PlayerHandleListener,
+  PlayerHandleTimeListener,
+  TimelineElement,
+  TimelineTimeRange,
+} from "./player";
 
 // Host overlays: draw over the preview in composition coordinates (see EditorShellProps.gestureOverlay)
 export { usePreviewCompositionRect } from "./components/editor/usePreviewCompositionRect";

packages/studio/src/player/hooks/usePlayerHandle.test.tsx

@@ -0,0 +1,152 @@
+// @vitest-environment happy-dom
+
+import React, { useEffect } from "react";
+import { act } from "react";
+import { createRoot } from "react-dom/client";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { NLEProvider, useNLEContext, type NLEContextValue } from "../../components/nle/NLEContext";
+import { liveTime, usePlayerStore } from "../store/playerStore";
+import { makeAdapterWindow, makeFakeIframe } from "./timelinePlayerTestHarness";
+import { usePlayerHandle, type PlayerHandle } from "./usePlayerHandle";
+
+Object.assign(globalThis, { IS_REACT_ACT_ENVIRONMENT: true });
+
+function renderHandle() {
+  let latest: PlayerHandle | null = null;
+  let context: NLEContextValue | null = null;
+  let renders = 0;
+  const host = document.createElement("div");
+  document.body.append(host);
+  const root = createRoot(host);
+  act(() => {
+    root.render(
+      <NLEProvider projectId="player-handle-test">
+        <HandleHarness
+          onContext={(value) => (context = value)}
+          onValue={(value) => (latest = value)}
+          onRender={() => renders++}
+        />
+      </NLEProvider>,
+    );
+  });
+  if (!latest || !context) throw new Error("usePlayerHandle did not mount");
+  return {
+    root,
+    getHandle: () => latest as PlayerHandle,
+    getContext: () => context as NLEContextValue,
+    getRenderCount: () => renders,
+  };
+}
+
+function HandleHarness({
+  onContext,
+  onValue,
+  onRender,
+}: {
+  onContext: (value: NLEContextValue) => void;
+  onValue: (value: PlayerHandle) => void;
+  onRender: () => void;
+}) {
+  onRender();
+  const context = useNLEContext();
+  const handle = usePlayerHandle();
+  useEffect(() => {
+    onContext(context);
+    onValue(handle);
+  }, [context, handle, onContext, onValue]);
+  return null;
+}
+
+afterEach(() => {
+  usePlayerStore.getState().reset();
+  document.body.innerHTML = "";
+});
+
+describe("usePlayerHandle", () => {
+  it("refuses seek before readiness and notifies structural changes independently", () => {
+    const { root, getHandle } = renderHandle();
+    const handle = getHandle();
+
+    expect(handle.ready).toBe(false);
+    expect(handle.seek(4)).toBe(false);
+
+    const structuralListener = vi.fn();
+    const unsubscribe = handle.subscribe(structuralListener);
+    act(() => usePlayerStore.setState({ timelineReady: true }));
+    expect(structuralListener).toHaveBeenCalledTimes(1);
+    act(() => usePlayerStore.setState({ duration: 8 }));
+    expect(structuralListener).toHaveBeenCalledTimes(2);
+    act(() =>
+      usePlayerStore.setState({
+        elements: [
+          {
+            id: "clip",
+            tag: "div",
+            start: 2,
+            duration: 3,
+            track: 0,
+            selector: "#clip",
+            sourceFile: "index.html",
+            compositionSrc: "compositions/intro.html",
+          },
+        ],
+      }),
+    );
+    expect(structuralListener).toHaveBeenCalledTimes(3);
+    expect(getHandle().elements).toEqual([
+      {
+        id: "clip",
+        start: 2,
+        end: 5,
+        selector: "#clip",
+        sourceFile: "index.html",
+        compositionSrc: "compositions/intro.html",
+      },
+    ]);
+
+    unsubscribe();
+    act(() => root.unmount());
+  });
+
+  it("uses the shell player to seek a real preview adapter after readiness", async () => {
+    const { root, getContext, getHandle } = renderHandle();
+    const { adapter, win } = makeAdapterWindow();
+    await act(async () => {
+      getContext().iframeRef.current = makeFakeIframe(win);
+      getContext().onIframeLoad();
+      await Promise.resolve();
+    });
+
+    expect(usePlayerStore.getState().timelineReady).toBe(true);
+    expect(getHandle().seek(4)).toBe(true);
+    expect(adapter.getTime()).toBe(4);
+    expect(usePlayerStore.getState().currentTime).toBe(4);
+    act(() => getHandle().play());
+    expect(getHandle().playing).toBe(true);
+
+    act(() => root.unmount());
+  });
+
+  it("keeps playback time out of React renders and forwards live time notifications", () => {
+    const { root, getHandle, getRenderCount } = renderHandle();
+    const initialRenderCount = getRenderCount();
+    const timeListener = vi.fn();
+    const structuralListener = vi.fn();
+    const unsubscribeTime = getHandle().subscribeTime(timeListener);
+    const unsubscribe = getHandle().subscribe(structuralListener);
+
+    act(() => {
+      usePlayerStore.setState({ currentTime: 2.5 });
+      liveTime.notify(7.25);
+    });
+
+    expect(getRenderCount()).toBe(initialRenderCount);
+    expect(getHandle().currentTime).toBe(2.5);
+    expect(timeListener).toHaveBeenCalledWith(7.25);
+    expect(structuralListener).not.toHaveBeenCalled();
+
+    unsubscribeTime();
+    unsubscribe();
+    act(() => root.unmount());
+  });
+});

packages/studio/src/player/hooks/usePlayerHandle.ts

@@ -0,0 +1,94 @@
+import { useCallback, useMemo } from "react";
+import { liveTime, usePlayerStore, type TimelineElement } from "../store/playerStore";
+import { useNLEContext } from "../../components/nle/NLEContext";
+
+export interface PlayerHandleElement {
+  id: string;
+  start: number;
+  end: number;
+  selector?: string;
+  sourceFile?: string;
+  compositionSrc?: string;
+}
+
+export type PlayerHandleListener = () => void;
+export type PlayerHandleTimeListener = (time: number) => void;
+
+export interface PlayerHandle {
+  ready: boolean;
+  playing: boolean;
+  seek: (seconds: number) => boolean;
+  play: () => void;
+  pause: () => void;
+  togglePlay: () => void;
+  readonly currentTime: number;
+  duration: number;
+  elements: PlayerHandleElement[];
+  subscribe: (listener: PlayerHandleListener) => () => void;
+  subscribeTime: (listener: PlayerHandleTimeListener) => () => void;
+}
+
+function toHandleElement(element: TimelineElement): PlayerHandleElement {
+  return {
+    id: element.id,
+    start: element.start,
+    end: element.start + element.duration,
+    selector: element.selector,
+    sourceFile: element.sourceFile,
+    compositionSrc: element.compositionSrc,
+  };
+}
+
+/**
+ * Reads and controls the shell player. Call this under EditorShell/NLEProvider;
+ * the provider owns the mounted preview iframe and the single player instance.
+ */
+export function usePlayerHandle(): PlayerHandle {
+  const { play, pause, togglePlay, seek: seekPlayer } = useNLEContext();
+  const ready = usePlayerStore((state) => state.timelineReady);
+  const playing = usePlayerStore((state) => state.isPlaying);
+  const duration = usePlayerStore((state) => state.duration);
+  const elements = usePlayerStore((state) => state.elements);
+
+  const seek = useCallback(
+    (seconds: number) => {
+      if (!ready) return false;
+      return seekPlayer(seconds);
+    },
+    [ready, seekPlayer],
+  );
+
+  const subscribe = useCallback((listener: PlayerHandleListener) => {
+    let previous = usePlayerStore.getState();
+    return usePlayerStore.subscribe((state) => {
+      const structuralChange =
+        state.timelineReady !== previous.timelineReady ||
+        state.isPlaying !== previous.isPlaying ||
+        state.duration !== previous.duration ||
+        state.elements !== previous.elements;
+      previous = state;
+      if (structuralChange) listener();
+    });
+  }, []);
+
+  const subscribeTime = useCallback((listener: PlayerHandleTimeListener) => {
+    return liveTime.subscribe(listener);
+  }, []);
+  const handleElements = useMemo(() => elements.map(toHandleElement), [elements]);
+
+  return {
+    ready,
+    playing,
+    seek,
+    play,
+    pause,
+    togglePlay,
+    get currentTime() {
+      return usePlayerStore.getState().currentTime;
+    },
+    duration,
+    elements: handleElements,
+    subscribe,
+    subscribeTime,
+  };
+}

packages/studio/src/player/index.ts

@@ -7,6 +7,13 @@ export { CompositionThumbnail } from "./components/CompositionThumbnail";
 
 // Hooks
 export { useTimelinePlayer } from "./hooks/useTimelinePlayer";
+export { usePlayerHandle } from "./hooks/usePlayerHandle";
+export type {
+  PlayerHandle,
+  PlayerHandleElement,
+  PlayerHandleListener,
+  PlayerHandleTimeListener,
+} from "./hooks/usePlayerHandle";
 export { resolveIframe } from "./lib/timelineDOM";
 
 // Store