sdk-target-based-on-call-view-model client -> slot/participation

sdk-target-based-on-call-view-model/README.md

@@ -2,8 +2,9 @@
 
 > Superseded by the `sdk/` package (`@element-hq/matrixrtc-sdk`) and its harness in
 > `sdk/dev`; see `sdk/SdkArchitecture.md`. This bundle is in production use, so it
-> keeps building as a thin layer over that package, with its interface unchanged,
-> until its consumers have moved to the package directly. It will then be removed.
+> keeps building as a thin layer over that package until its consumers have moved
+> to the package directly. It will then be removed. Its members are the package's
+> `RTCMember`s now, in place of its own wrapper around the raw membership.
 
 EC can be build in sdk mode. This will result in a compiled js file that can be imported in very simple webapps.
 

sdk-target-based-on-call-view-model/helper.ts

@@ -1,29 +0,0 @@
-/*
-Copyright 2025 Element Creations Ltd.
-
-SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE in the repository root for full details.
-*/
-
-/**
- * This file contains helper functions and types for the legacy SDK bundle.
- */
-
-import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
-
-import { type WidgetHelpers } from "../src/widget";
-
-export const tryMakeSticky = (widget: WidgetHelpers): void => {
-  const logger = rootLogger.getChild("[MatrixRTCSdk]");
-  logger.info("try making sticky MatrixRTCSdk");
-  void widget.api
-    .setAlwaysOnScreen(true)
-    .then(() => {
-      logger.info("sticky MatrixRTCSdk");
-    })
-    .catch((error) => {
-      logger.error("failed to make sticky MatrixRTCSdk", error);
-    });
-};
-/** The data channel topic this bundle has always used, so that old and new builds talk. */
-export const TEXT_LK_TOPIC = "matrixRTC";

sdk-target-based-on-call-view-model/index.html

@@ -35,7 +35,7 @@
         div.innerHTML = "<h3>Members:</h3>";
 
         // Create member list
-        const members = memberObjects.map((member) => member.membership.sender);
+        const members = memberObjects.map((member) => member.userId);
         console.info("members changed", members);
         for (const m of members) {
           console.info("member", m);

sdk-target-based-on-call-view-model/main.ts

@@ -8,125 +8,80 @@ Please see LICENSE in the repository root for full details.
 /**
  * LEGACY, in production use
  *
- * This file is the entrypoint of the legacy SDK bundle,
- * `pnpm build:sdk-target-based-on-call-view-model`, for use in widgets. It
- * exposes `createMatrixRTCSdk`, which creates the `MatrixRTCSdk` interface
- * (see below) to join an RTC session and exchange realtime data.
- *
- * It is a thin layer over the `@element-hq/matrixrtc-sdk` package and Element
- * Call's call view model, which take care of all the tricky bits:
- *  - sending delayed events
- *  - finding the right sfu
- *  - handling the media stream
- *  - sending join/leave state or sticky events
- *  - setting up encryption and sharing keys
- *
- * The interface is kept as it was for its existing consumers. New consumers
- * use the `@element-hq/matrixrtc-sdk` package directly; this bundle goes away
- * once the existing ones have moved.
+ * The entrypoint of `pnpm build:sdk-target-based-on-call-view-model`, a
+ * bundle for widgets that exposes `createMatrixRTCSdk`: join a slot and
+ * exchange realtime data, with the `@element-hq/matrixrtc-sdk` package and
+ * Element Call's call view model doing the work underneath. New consumers use
+ * the package directly; this bundle goes away once the existing ones have.
  */
 
-import {
-  combineLatest,
-  filter,
-  map,
-  type Observable,
-  of,
-  switchMap,
-} from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
+import { EMPTY, filter, map, type Observable, of, switchMap, take } from "rxjs";
 import {
   type Behavior,
-  createMatrixRTCClient,
+  createRTCSlot,
   E2eeType,
+  type LocalRTCMember,
   ObservableScope,
-  type RTCMember,
-  type RTCMembership,
+  type RemoteRTCMember,
+  type RTCParticipation,
 } from "@element-hq/matrixrtc-sdk";
 
 import {
   callViewModelOptionsFromParams,
+  type CallViewModel,
   createCallViewModel$,
   initialPublishRequests,
 } from "../src/state/CallViewModel/CallViewModel";
-import { getUrlParams } from "../src/UrlParams";
-import { MuteStates } from "../src/state/MuteStates";
-import { MediaDevices } from "../src/state/MediaDevices";
-import { TEXT_LK_TOPIC, tryMakeSticky } from "./helper";
-import { initializeWidget } from "../src/widget";
-import { createWidgetHostBridge } from "../src/HostBridge";
-import { observeElementSize$ } from "../src/utils/elementSize";
 import {
   captureSettings,
-  matrixRTCClientOptions,
+  rtcParticipationOptions,
+  rtcSlotOptions,
 } from "../src/room/InCallView";
+import { createWidgetHostBridge } from "../src/HostBridge";
+import { MediaDevices } from "../src/state/MediaDevices";
+import { MuteStates } from "../src/state/MuteStates";
+import { getUrlParams } from "../src/UrlParams";
+import { observeElementSize$ } from "../src/utils/elementSize";
+import { initializeWidget } from "../src/widget";
 
-/**
- * A member as this bundle has always presented it. The media transport is
- * the SDK's business now, so the transport objects are gone: `connection` and
- * `participant` are always null and only kept so that existing code keeps
- * destructuring. `membership` is what consumers read.
- */
-interface MatrixRTCSdkMember {
-  /** @deprecated Always null: the SDK owns the transport connection. */
-  connection: null;
-  membership: RTCMembership;
-  /** @deprecated Always null: the SDK owns the transport participant. */
-  participant: null;
-}
+/** The data channel topic this bundle has always used, so that old and new builds talk. */
+const TOPIC = "matrixRTC";
 
-interface MatrixRTCSdk {
-  /**
-   * observe connected$ to track the state.
-   * @returns
-   */
+export interface MatrixRTCSdk {
+  /** Joins the slot; `connected$` tracks the progress. A second call does nothing. */
   join: () => void;
-  /** @throws on leave errors */
   leave: () => void;
-  /**
-   * Ends the rtc sdk. This will unsubscribe any event listeners. And end the associated scope.
-   * No updates can be received from the rtc sdk. The sdk cannot be restarted after.
-   * A new sdk needs to be created via createMatrixRTCSdk.
-   */
+  /** Ends everything. The sdk cannot be restarted; create a new one. */
   stop: () => void;
-  data$: Observable<{ rtcBackendIdentity: string; data: string }>;
-  /**
-   * flattened list of remote members
-   */
-  remoteMembers$: Behavior<MatrixRTCSdkMember[]>;
-  /**
-   * flattened local member
-   */
-  localMember$: Behavior<MatrixRTCSdkMember | null>;
-  /** Use the LocalMemberConnectionState returned from `join` for a more detailed connection state  */
   connected$: Behavior<boolean>;
-  sendData?: (data: unknown) => Promise<void>;
-  sendRoomMessage?: (message: string) => Promise<void>;
+  /** Our own member, null until our membership has been seen in the room. */
+  localMember$: Behavior<LocalRTCMember | null>;
+  /** The other members of the slot, with the media the participation carries for them. */
+  remoteMembers$: Behavior<RemoteRTCMember[]>;
+  /** What other members sent with `sendData`. */
+  data$: Observable<{ rtcBackendIdentity: string; data: string }>;
+  /** Sends to every member on our transport. Rejects while not joined. */
+  sendData: (data: unknown) => Promise<void>;
+  sendRoomMessage: (message: string) => Promise<void>;
 }
 
 export async function createMatrixRTCSdk(
-  application: string = "m.call",
-  id: string = "",
-  sticky: boolean = false,
+  application = "m.call",
+  id = "",
+  sticky = false,
 ): Promise<MatrixRTCSdk> {
   const logger = rootLogger.getChild("[MatrixRTCSdk]");
   const scope = new ObservableScope();
-
-  // widget client
   const widget = initializeWidget(application, true);
-  if (!widget) throw Error("No widget. This webapp can only start as a widget");
+  if (!widget) throw new Error("No widget: this bundle only runs as a widget");
   const client = await widget.client;
   const hostBridge = createWidgetHostBridge(widget);
-  logger.info("client created");
-
-  // url params
   const urlParams = getUrlParams();
   const { roomId, controlledAudioDevices, callIntent } = urlParams;
-  if (roomId === null) throw Error("could not get roomId from url params");
-  const room = client.getRoom(roomId);
-  if (room === null) throw Error("could not get room from client");
+  const room = roomId === null ? null : client.getRoom(roomId);
+  if (room === null) throw new Error("No room: the url needs a joined roomId");
 
-  // media devices
   const mediaDevices = new MediaDevices(scope, {
     controlledAudioDevices,
     callIntent,
@@ -137,136 +92,97 @@ export async function createMatrixRTCSdk(
     { audioEnabled: false, videoEnabled: false },
     hostBridge,
   );
-
-  // rtc client: the session, the transport and the media, as in the app
   const encryptionSystem = { kind: E2eeType.PER_PARTICIPANT } as const;
   const capture = captureSettings();
-  const rtcClient = createMatrixRTCClient(scope, client, room, {
-    ...matrixRTCClientOptions(urlParams, encryptionSystem),
-    publish: initialPublishRequests(muteStates, mediaDevices, capture),
+  const slot = createRTCSlot(scope, client, room, {
+    ...rtcSlotOptions(encryptionSystem),
     application,
-    slot: id,
+    id,
   });
+  let vm: CallViewModel | undefined;
+  const failed =
+    (what: string) =>
+    (e: unknown): void =>
+      logger.error(what, e);
 
-  // call view model: the host bridge's hang-up handling and the leave flow
-  const callViewModel = createCallViewModel$(
-    scope,
-    rtcClient,
-    room,
-    mediaDevices,
-    muteStates,
-    {
-      ...callViewModelOptionsFromParams(urlParams),
-      encryptionSystem,
-      capture,
-      hostBridge,
-      // The SDK owns its page, so the body is the space it has
-      windowSize$: scope.behavior(observeElementSize$(document.body)),
-    },
-    of({}),
-    of({}),
-  );
-  logger.info("CallViewModelCreated");
-
-  // Data arrives from attested members only; the SDK has matched the sender
-  const data$ = rtcClient.data$.pipe(
-    filter(({ topic }) => topic === TEXT_LK_TOPIC),
-    map(({ member, text }) => {
-      logger.info(`Received text from ${member.id}: ${text}`);
-      return { rtcBackendIdentity: member.id, data: text };
-    }),
-  );
-
-  const sendData = async (data: unknown): Promise<void> => {
-    const dataString = JSON.stringify(data);
-    logger.info("try sending: ", dataString);
-    try {
-      await rtcClient.sendData(TEXT_LK_TOPIC, dataString);
-      logger.info("sent text");
-    } catch (e) {
-      logger.error("failed sending: ", dataString, e);
-    }
-  };
-
-  const sendRoomMessage = async (message: string): Promise<void> => {
-    const messageString = JSON.stringify(message);
-    logger.info("try sending to room: ", messageString);
-    try {
-      await client.sendTextMessage(room.roomId, message);
-    } catch (e) {
-      logger.error("failed sending to room: ", messageString, e);
-    }
-  };
-
-  // after hangup gets called
-  const leaveSubs = callViewModel.leave$.subscribe(() => {
-    const scheduleWidgetCloseOnLeave = async (): Promise<void> => {
-      logger.info("waiting for RTC leave");
-      await new Promise<void>((resolve) => {
-        rtcClient.status$
-          .pipe(filter((status) => status === "disconnected"))
-          .subscribe(() => resolve());
-      });
-      logger.info("send Unstick");
-      await hostBridge
-        .setAlwaysOnScreen(false)
-        .catch((e: unknown) =>
-          logger.error("Failed to set `alwaysOnScreen` to false", e),
-        );
-      logger.info("send Close");
-      await hostBridge
-        .close?.()
-        .catch((e: unknown) =>
-          logger.error("Failed to ask the host to close", e),
-        );
-    };
-
-    // schedule close first and then leave (scope.end)
-    void scheduleWidgetCloseOnLeave();
-  });
-
-  logger.info("createMatrixRTCSdk done");
-
-  const flatten = (member: RTCMember): Observable<MatrixRTCSdkMember> =>
-    member.membership$.pipe(
-      map((membership) => ({
-        connection: null,
-        membership,
-        participant: null,
-      })),
+  const over = <T>(
+    pick: (participation: RTCParticipation) => Observable<T>,
+    fallback: T,
+  ): Behavior<T> =>
+    scope.behavior(
+      slot.participation$.pipe(
+        switchMap((p) => (p === null ? of(fallback) : pick(p))),
+      ),
     );
 
   return {
     join: (): void => {
-      // first lets try making the widget sticky
-      if (sticky) tryMakeSticky(widget);
-      callViewModel.join();
+      if (slot.participation$.value !== null) return;
+      if (sticky)
+        widget.api
+          .setAlwaysOnScreen(true)
+          .catch(failed("Failed to make the widget sticky"));
+      const participation = slot.join({
+        ...rtcParticipationOptions(urlParams),
+        publish: initialPublishRequests(muteStates, mediaDevices, capture),
+      });
+      vm = createCallViewModel$(
+        scope,
+        participation,
+        room,
+        mediaDevices,
+        muteStates,
+        {
+          ...callViewModelOptionsFromParams(urlParams),
+          encryptionSystem,
+          capture,
+          hostBridge,
+          // The bundle owns its page, so the body is the space it has
+          windowSize$: scope.behavior(observeElementSize$(document.body)),
+        },
+        of({}),
+        of({}),
+      );
+      // Once the hang-up has gone through, unstick and ask the host to close us
+      vm.leave$
+        .pipe(
+          switchMap(() =>
+            participation.status$.pipe(
+              filter((status) => status === "left"),
+              take(1),
+            ),
+          ),
+          scope.bind(),
+        )
+        .subscribe(() => {
+          hostBridge
+            .setAlwaysOnScreen(false)
+            .catch(failed("Failed to unstick the widget"))
+            .then(() => hostBridge.close?.())
+            .catch(failed("Failed to ask the host to close"));
+        });
     },
-    leave: (): void => {
-      callViewModel.leave();
-    },
-    stop: (): void => {
-      leaveSubs.unsubscribe();
-      scope.end();
-    },
-    data$,
-    localMember$: scope.behavior(
-      rtcClient.localMember$.pipe(
-        switchMap((member) => (member === null ? of(null) : flatten(member))),
-      ),
+    leave: (): void => vm?.leave(),
+    stop: (): void => scope.end(),
+    connected$: over((p) => p.connected$, false),
+    localMember$: over((p) => p.localMember$, null),
+    remoteMembers$: over((p) => p.remoteMembers$, []),
+    // Attested members only: the SDK has matched the sender
+    data$: slot.participation$.pipe(
+      switchMap((p) => p?.data$ ?? EMPTY),
+      filter(({ topic }) => topic === TOPIC),
+      map(({ member, text }) => ({
+        rtcBackendIdentity: member.rtcBackendIdentity,
+        data: text,
+      })),
     ),
-    connected$: callViewModel.connected$,
-    remoteMembers$: scope.behavior(
-      rtcClient.remoteMembers$.pipe(
-        switchMap((members) =>
-          members.length === 0
-            ? of([])
-            : combineLatest(members.map((member) => flatten(member))),
-        ),
-      ),
-      [],
-    ),
-    sendData,
-    sendRoomMessage,
+    sendData: async (data): Promise<void> => {
+      const participation = slot.participation$.value;
+      if (participation === null) throw new Error("Not joined");
+      await participation.sendData(TOPIC, JSON.stringify(data));
+    },
+    sendRoomMessage: async (message): Promise<void> => {
+      await client.sendTextMessage(room.roomId, message);
+    },
   };
 }