Fix: Camera is not muted when the earpiece mode is enabled

src/state/MuteStates.test.ts

@@ -0,0 +1,212 @@
+/*
+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.
+*/
+
+import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
+import { BehaviorSubject } from "rxjs";
+import { logger } from "matrix-js-sdk/lib/logger";
+
+import { MuteStates, MuteState } from "./MuteStates";
+import {
+  type AudioOutputDeviceLabel,
+  type DeviceLabel,
+  type MediaDevice,
+  type SelectedAudioOutputDevice,
+  type SelectedDevice,
+} from "./MediaDevices";
+import { constant } from "./Behavior";
+import { ObservableScope } from "./ObservableScope";
+import { flushPromises, mockMediaDevices } from "../utils/test";
+
+const getUrlParams = vi.hoisted(() => vi.fn(() => ({})));
+vi.mock("../UrlParams", () => ({ getUrlParams }));
+
+let testScope: ObservableScope;
+
+beforeEach(() => {
+  testScope = new ObservableScope();
+});
+
+afterEach(() => {
+  testScope.end();
+});
+
+describe("MuteState", () => {
+  test("should automatically mute if force mute is set", async () => {
+    const forceMute$ = new BehaviorSubject<boolean>(false);
+
+    const deviceStub = {
+      available$: constant(
+        new Map<string, DeviceLabel>([
+          ["fbac11", { type: "name", name: "HD Camera" }],
+        ]),
+      ),
+      selected$: constant({ id: "fbac11" }),
+      select(): void {},
+    } as unknown as MediaDevice<DeviceLabel, SelectedDevice>;
+
+    const muteState = new MuteState(
+      testScope,
+      deviceStub,
+      constant(true),
+      true,
+      forceMute$,
+    );
+    let lastEnabled: boolean = false;
+    muteState.enabled$.subscribe((enabled) => {
+      lastEnabled = enabled;
+    });
+    let setEnabled: ((enabled: boolean) => void) | null = null;
+    muteState.setEnabled$.subscribe((setter) => {
+      setEnabled = setter;
+    });
+
+    await flushPromises();
+
+    setEnabled!(true);
+    await flushPromises();
+    expect(lastEnabled).toBe(true);
+
+    // Now force mute
+    forceMute$.next(true);
+    await flushPromises();
+    // Should automatically mute
+    expect(lastEnabled).toBe(false);
+
+    // Try to unmute can not work
+    expect(setEnabled).toBeNull();
+
+    // Disable force mute
+    forceMute$.next(false);
+    await flushPromises();
+
+    // TODO I'd expect it to go back to previous state (enabled)
+    // but actually it goes back to the initial state from construction (disabled)
+    // Should go back to previous state (enabled)
+    // Skip for now
+    // expect(lastEnabled).toBe(true);
+
+    // But yet it can be unmuted now
+    expect(setEnabled).not.toBeNull();
+
+    setEnabled!(true);
+    await flushPromises();
+    expect(lastEnabled).toBe(true);
+  });
+});
+
+describe("MuteStates", () => {
+  function aAudioOutputDevices(): MediaDevice<
+    AudioOutputDeviceLabel,
+    SelectedAudioOutputDevice
+  > {
+    const selected$ = new BehaviorSubject<
+      SelectedAudioOutputDevice | undefined
+    >({
+      id: "default",
+      virtualEarpiece: false,
+    });
+    return {
+      available$: constant(
+        new Map<string, AudioOutputDeviceLabel>([
+          ["default", { type: "speaker" }],
+          ["0000", { type: "speaker" }],
+          ["1111", { type: "earpiece" }],
+          ["222", { type: "name", name: "Bluetooth Speaker" }],
+        ]),
+      ),
+      selected$,
+      select(id: string): void {
+        if (!this.available$.getValue().has(id)) {
+          logger.warn(`Attempted to select unknown device id: ${id}`);
+          return;
+        }
+        selected$.next({
+          id,
+          /** For test purposes we ignore this */
+          virtualEarpiece: false,
+        });
+      },
+    };
+  }
+
+  function aVideoInput(): MediaDevice<DeviceLabel, SelectedDevice> {
+    const selected$ = new BehaviorSubject<SelectedDevice | undefined>(
+      undefined,
+    );
+    return {
+      available$: constant(
+        new Map<string, DeviceLabel>([
+          ["0000", { type: "name", name: "HD Camera" }],
+          ["1111", { type: "name", name: "WebCam Pro" }],
+        ]),
+      ),
+      selected$,
+      select(id: string): void {
+        if (!this.available$.getValue().has(id)) {
+          logger.warn(`Attempted to select unknown device id: ${id}`);
+          return;
+        }
+        selected$.next({ id });
+      },
+    };
+  }
+
+  test("should mute camera when in earpiece mode", async () => {
+    const audioOutputDevice = aAudioOutputDevices();
+
+    const mediaDevices = mockMediaDevices({
+      audioOutput: audioOutputDevice,
+      videoInput: aVideoInput(),
+      // other devices are not relevant for this test
+    });
+    const muteStates = new MuteStates(
+      testScope,
+      mediaDevices,
+      // consider joined
+      constant(true),
+    );
+
+    let latestSyncedState: boolean | null = null;
+    muteStates.video.setHandler(async (enabled: boolean): Promise<boolean> => {
+      logger.info(`Video mute state set to: ${enabled}`);
+      latestSyncedState = enabled;
+      return Promise.resolve(enabled);
+    });
+
+    let lastVideoEnabled: boolean = false;
+    muteStates.video.enabled$.subscribe((enabled) => {
+      lastVideoEnabled = enabled;
+    });
+
+    expect(muteStates.video.setEnabled$.value).toBeDefined();
+    muteStates.video.setEnabled$.value?.(true);
+    await flushPromises();
+
+    expect(lastVideoEnabled).toBe(true);
+
+    // Select earpiece audio output
+    audioOutputDevice.select("1111");
+    await flushPromises();
+    // Video should be automatically muted
+    expect(lastVideoEnabled).toBe(false);
+    expect(latestSyncedState).toBe(false);
+
+    // Try to switch to speaker
+    audioOutputDevice.select("0000");
+    await flushPromises();
+    // TODO I'd expect it to go back to previous state (enabled)??
+    // But maybe not? If you move the phone away from your ear you may not want it
+    // to automatically enable video?
+    expect(lastVideoEnabled).toBe(false);
+
+    // But yet it can be unmuted now
+    expect(muteStates.video.setEnabled$.value).toBeDefined();
+    muteStates.video.setEnabled$.value?.(true);
+    await flushPromises();
+    expect(lastVideoEnabled).toBe(true);
+  });
+});

src/state/MuteStates.ts

@@ -27,7 +27,7 @@ import { ElementWidgetActions, widget } from "../widget";
 import { Config } from "../config/Config";
 import { getUrlParams } from "../UrlParams";
 import { type ObservableScope } from "./ObservableScope";
-import { type Behavior } from "./Behavior";
+import { type Behavior, constant } from "./Behavior";
 
 interface MuteStateData {
   enabled$: Observable<boolean>;
@@ -38,31 +38,58 @@ interface MuteStateData {
 export type Handler = (desired: boolean) => Promise<boolean>;
 const defaultHandler: Handler = async (desired) => Promise.resolve(desired);
 
-class MuteState<Label, Selected> {
+/**
+ * Internal class - exported only for testing purposes.
+ * Do not use directly outside of tests.
+ */
+export class MuteState<Label, Selected> {
+  // TODO: rewrite this to explain behavior, it is not understandable, and cannot add logging
   private readonly enabledByDefault$ =
     this.enabledByConfig && !getUrlParams().skipLobby
       ? this.joined$.pipe(map((isJoined) => !isJoined))
       : of(false);
 
   private readonly handler$ = new BehaviorSubject(defaultHandler);
+
   public setHandler(handler: Handler): void {
     if (this.handler$.value !== defaultHandler)
       throw new Error("Multiple mute state handlers are not supported");
     this.handler$.next(handler);
   }
+
   public unsetHandler(): void {
     this.handler$.next(defaultHandler);
   }
 
+  private readonly devicesConnected$ = combineLatest([
+    this.device.available$,
+    this.forceMute$,
+  ]).pipe(
+    map(([available, forceMute]) => {
+      return !forceMute && available.size > 0;
+    }),
+  );
+
   private readonly data$ = this.scope.behavior<MuteStateData>(
-    this.device.available$.pipe(
-      map((available) => available.size > 0),
+    this.devicesConnected$.pipe(
       distinctUntilChanged(),
       withLatestFrom(
         this.enabledByDefault$,
         (devicesConnected, enabledByDefault) => {
-          if (!devicesConnected)
+          logger.info(
+            `MuteState: devices connected: ${devicesConnected}, enabled by default: ${enabledByDefault}`,
+          );
+          if (!devicesConnected) {
+            logger.info(
+              `MuteState: devices connected: ${devicesConnected}, disabling`,
+            );
+            // We need to sync the mute state with the handler
+            // to ensure nothing is beeing published.
+            this.handler$.value(false).catch((err) => {
+              logger.error("MuteState-disable: handler error", err);
+            });
             return { enabled$: of(false), set: null, toggle: null };
+          }
 
           // Assume the default value only once devices are actually connected
           let enabled = enabledByDefault;
@@ -135,21 +162,45 @@ class MuteState<Label, Selected> {
     private readonly device: MediaDevice<Label, Selected>,
     private readonly joined$: Observable<boolean>,
     private readonly enabledByConfig: boolean,
+    /**
+     * An optional observable which, when it emits `true`, will force the mute.
+     * Used for video to stop camera when earpiece mode is on.
+     * @private
+     */
+    private readonly forceMute$: Observable<boolean>,
   ) {}
 }
 
 export class MuteStates {
+  /**
+   *  True if the selected audio output device is an earpiece.
+   *  Used to force-disable video when on earpiece.
+   */
+  private readonly isEarpiece$ = combineLatest(
+    this.mediaDevices.audioOutput.available$,
+    this.mediaDevices.audioOutput.selected$,
+  ).pipe(
+    map(([available, selected]) => {
+      if (!selected?.id) return false;
+      const device = available.get(selected.id);
+      logger.info(`MuteStates: selected audio output device:`, device);
+      return device?.type === "earpiece";
+    }),
+  );
+
   public readonly audio = new MuteState(
     this.scope,
     this.mediaDevices.audioInput,
     this.joined$,
     Config.get().media_devices.enable_audio,
+    constant(false),
   );
   public readonly video = new MuteState(
     this.scope,
     this.mediaDevices.videoInput,
     this.joined$,
     Config.get().media_devices.enable_video,
+    this.isEarpiece$,
   );
 
   public constructor(