feat: stream private office screens

src/media/remoteMedia.ts

@@ -60,11 +60,22 @@ export interface PresenterStart {
   stream: MediaStream;
   video: HTMLVideoElement;
 }
-export interface ViewerStart {
-  /** A current `authorizeMediaSurface` decision with explicit viewer opt-in. */
-  decision: MediaAuthorizationDecision;
-  video: HTMLVideoElement;
-}
+export type ViewerStart =
+  | {
+      /** A current `authorizeMediaSurface` decision with explicit viewer opt-in. */
+      decision: MediaAuthorizationDecision;
+      viewerOptIn?: never;
+      video: HTMLVideoElement;
+    }
+  | {
+      /**
+       * Literal user action for signaling servers that perform authorization
+       * during join and intentionally expose no source locator to the client.
+       */
+      decision?: never;
+      viewerOptIn: true;
+      video: HTMLVideoElement;
+    };
 export interface RemoteOfficeMedia {
   startPresenter(input: PresenterStart): Promise<void>;
   startViewer(input: ViewerStart): Promise<void>;
@@ -310,6 +321,10 @@ export function createRemoteOfficeMedia(options: RemoteOfficeMediaOptions): Remo
     cursor = advanced.value;
     if (message.type === "screen-share-stopped") {
       closeTransport();
+      // The server has already destroyed the signaling session. Forget the
+      // capability now so caller cleanup cannot issue a redundant leave that
+      // is guaranteed to fail authorization.
+      grant = null;
       setStatus("stopped");
       return;
     }
@@ -412,7 +427,10 @@ export function createRemoteOfficeMedia(options: RemoteOfficeMediaOptions): Remo
     if (!message.continuous) resetPeerMesh();
     await reconcile(message.participants);
     scheduleRenewal();
-    setStatus("connecting");
+    // A presenter with no viewers is still live: the hosted signaling session
+    // is accepting authorized viewers. A viewer remains connecting until its
+    // receive-only peer actually reaches the connected state.
+    setStatus(options.role === "presenter" && peers.size === 0 ? "live" : "connecting");
     return true;
   }
 
@@ -492,6 +510,7 @@ export function createRemoteOfficeMedia(options: RemoteOfficeMediaOptions): Remo
     cursor = { sessionId: response.grant.credential.sessionId, sequence: response.sequence, timestampMs: response.timestampMs };
     await reconcile(response.participants);
     scheduleRenewal();
+    if (role === "presenter" && peers.size === 0) setStatus("live");
     void startEvents().catch((reason) => { options.onError?.(asError(reason, "remote media events failed")); scheduleReconnect(); });
   }
 
@@ -525,9 +544,12 @@ export function createRemoteOfficeMedia(options: RemoteOfficeMediaOptions): Remo
   async function startViewer(input: ViewerStart): Promise<void> {
     if (options.role !== "viewer") throw new Error("remote media: adapter is not a viewer");
     if (status === "disposed" || status === "revoked") throw new Error("remote media: session is terminal");
-    if (!input.decision.authorized || !input.decision.optedIn || !input.decision.canView ||
-        input.decision.surface.screenId !== binding.screenId || input.decision.surface.officeId !== binding.officeId ||
-        input.decision.surface.source?.kind !== "live-stream") {
+    const ready = input.decision === undefined
+      ? input.viewerOptIn === true
+      : input.decision.authorized && input.decision.optedIn && input.decision.canView &&
+        input.decision.surface.screenId === binding.screenId && input.decision.surface.officeId === binding.officeId &&
+        input.decision.surface.source?.kind === "live-stream";
+    if (!ready) {
       throw new Error("remote media: a ready live-stream authorization decision is required");
     }
     input.video.autoplay = false;