Let the component own its mute state

ElementCallView took muteStates as a prop, which would have meant an
embedder building one before it could show a call. It could not simply make
its own: RoomPage created one on mount whichever branch it went on to
render, and two would both report the user's mute state to the host,
talking over each other.

Move the construction into a useMuteStates hook, and give the lobby shown
while waiting to be let into a room its own component. Each lobby now holds
mute state only while it is on screen, so there is never a second one, and
the component can own the call's.

KnockLobbyView also takes the room summary and label handling that RoomPage
was assembling on its behalf, leaving the page with arriving at a call
rather than being in one.

src/room/KnockLobbyView.tsx

@@ -0,0 +1,92 @@
+/*
+Copyright 2026 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 { type FC, type JSX, type ReactNode } from "react";
+import { type MatrixClient, type RoomSummary } from "matrix-js-sdk";
+import { useTranslation } from "react-i18next";
+import { CheckIcon } from "@vector-im/compound-design-tokens/assets/web/icons";
+
+import { LobbyView } from "./LobbyView";
+import { E2eeType } from "../e2ee/e2eeType";
+import { useMuteStates } from "../state/useMuteStates";
+
+interface Props {
+  client: MatrixClient;
+  /** What we know about the room from peeking at it. */
+  roomSummary: RoomSummary;
+  /** The user's own name and avatar, to show in their own tile. */
+  profile: { displayName: string; avatarUrl: string };
+  /**
+   * Asks to be let in, if the room allows it. Absent once we have asked and
+   * are waiting for an answer.
+   */
+  knock: (() => void) | null;
+  confineToRoom: boolean;
+  hideHeader: boolean;
+}
+
+/**
+ * The lobby shown while the user is outside a room they want to call in —
+ * either able to ask to join, or waiting for someone to answer.
+ *
+ * This belongs to the app shell rather than to the call: it exists precisely
+ * because there is no call to be in yet. It keeps its own mute state, which is
+ * why it is a component rather than part of the page — so that the call's mute
+ * state and this one are never alive at the same time, reporting over each
+ * other to the host.
+ */
+export const KnockLobbyView: FC<Props> = ({
+  client,
+  roomSummary,
+  profile,
+  knock,
+  confineToRoom,
+  hideHeader,
+}): ReactNode => {
+  const { t } = useTranslation();
+  const muteStates = useMuteStates();
+
+  if (muteStates === null) return null;
+
+  const waitingForInvite = knock === null;
+  const enterLabel: string | JSX.Element = waitingForInvite ? (
+    <>
+      {t("lobby.waiting_for_invite")}
+      <CheckIcon />
+    </>
+  ) : (
+    t("lobby.ask_to_join")
+  );
+
+  return (
+    <LobbyView
+      client={client}
+      matrixInfo={{
+        userId: client.getUserId() ?? "",
+        displayName: profile.displayName,
+        avatarUrl: profile.avatarUrl,
+        roomAlias: null,
+        roomId: roomSummary.room_id,
+        roomName: roomSummary.name ?? "",
+        roomAvatar: roomSummary.avatar_url ?? null,
+        e2eeSystem: {
+          kind: roomSummary["im.nheko.summary.encryption"]
+            ? E2eeType.PER_PARTICIPANT
+            : E2eeType.NONE,
+        },
+      }}
+      onEnter={(): void => knock?.()}
+      enterLabel={enterLabel}
+      waitingForInvite={waitingForInvite}
+      confineToRoom={confineToRoom}
+      hideHeader={hideHeader}
+      participantCount={null}
+      muteStates={muteStates}
+      onShareClick={null}
+    />
+  );
+};

src/room/RoomPage.tsx

@@ -6,21 +6,11 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import {
-  type FC,
-  useEffect,
-  useState,
-  type ReactNode,
-  useRef,
-  type JSX,
-} from "react";
+import { type FC, useEffect, useState, type ReactNode, useRef } from "react";
 import { type MatrixError } from "matrix-js-sdk";
 import { logger } from "matrix-js-sdk/lib/logger";
 import { Trans, useTranslation } from "react-i18next";
-import {
-  CheckIcon,
-  UnknownSolidIcon,
-} from "@vector-im/compound-design-tokens/assets/web/icons";
+import { UnknownSolidIcon } from "@vector-im/compound-design-tokens/assets/web/icons";
 
 import { useClientLegacy } from "../ClientContext";
 import { ErrorPage, FullScreenView, LoadingPage } from "../FullScreenView";
@@ -29,22 +19,15 @@ import { ElementCallView } from "../ElementCallView";
 import { useRoomIdentifier, useUrlParams } from "../UrlParams";
 import { useRegisterPasswordlessUser } from "../auth/useRegisterPasswordlessUser";
 import { HomePage } from "../home/HomePage";
-import { useHostBridge } from "../HostBridge.ts";
 import { CallTerminatedMessage, useLoadGroupCall } from "./useLoadGroupCall";
-import { LobbyView } from "./LobbyView";
-import { E2eeType } from "../e2ee/e2eeType";
+import { KnockLobbyView } from "./KnockLobbyView";
 import { useProfile } from "../profile/useProfile";
 import { useOptInAnalytics } from "../settings/settings";
 import { Link } from "../button/Link";
 import { ErrorView } from "../ErrorView";
-import { useMediaDevices } from "../MediaDevicesContext";
-import { MuteStates } from "../state/MuteStates";
-import { ObservableScope } from "../state/ObservableScope";
-import { calculateInitialMuteState } from "../state/initialMuteState.ts";
 
 export const RoomPage: FC = (): ReactNode => {
   const urlParams = useUrlParams();
-  const hostBridge = useHostBridge();
   const { confineToRoom, preload, header, displayName, skipLobby } = urlParams;
   const { t } = useTranslation();
   const { roomAlias, roomId, viaServers } = useRoomIdentifier();
@@ -63,26 +46,6 @@ export const RoomPage: FC = (): ReactNode => {
 
   const groupCallState = useLoadGroupCall(client, roomIdOrAlias, viaServers);
 
-  const devices = useMediaDevices();
-  const [muteStates, setMuteStates] = useState<MuteStates | null>(null);
-
-  useEffect(() => {
-    const scope = new ObservableScope();
-    setMuteStates(
-      new MuteStates(
-        scope,
-        devices,
-        calculateInitialMuteState(
-          urlParams.skipLobby,
-          urlParams.callIntent,
-          urlParams.isWidget,
-        ),
-        hostBridge,
-      ),
-    );
-    return (): void => scope.end();
-  }, [devices, urlParams, hostBridge]);
-
   useEffect(() => {
     // If we've finished loading, are not already authed and we've been given a display name as
     // a URL param, automatically register a passwordless user
@@ -123,64 +86,34 @@ export const RoomPage: FC = (): ReactNode => {
     switch (groupCallState.kind) {
       case "loaded":
         return (
-          muteStates && (
-            <ElementCallView
-              client={client!}
-              rtcSession={groupCallState.rtcSession}
-              isPasswordlessUser={passwordlessUser}
-              confineToRoom={confineToRoom}
-              preload={preload}
-              skipLobby={skipLobby || wasInWaitForInviteState.current}
-              muteStates={muteStates}
-            />
-          )
+          <ElementCallView
+            client={client!}
+            rtcSession={groupCallState.rtcSession}
+            isPasswordlessUser={passwordlessUser}
+            confineToRoom={confineToRoom}
+            preload={preload}
+            skipLobby={skipLobby || wasInWaitForInviteState.current}
+          />
         );
       case "waitForInvite":
       case "canKnock": {
         wasInWaitForInviteState.current =
           wasInWaitForInviteState.current ||
           groupCallState.kind === "waitForInvite";
-        const knock =
-          groupCallState.kind === "canKnock" ? groupCallState.knock : null;
-        const label: string | JSX.Element =
-          groupCallState.kind === "canKnock" ? (
-            t("lobby.ask_to_join")
-          ) : (
-            <>
-              {t("lobby.waiting_for_invite")}
-              <CheckIcon />
-            </>
-          );
         return (
-          muteStates && (
-            <LobbyView
-              client={client!}
-              matrixInfo={{
-                userId: client!.getUserId() ?? "",
-                displayName: userDisplayName ?? "",
-                avatarUrl: avatarUrl ?? "",
-                roomAlias: null,
-                roomId: groupCallState.roomSummary.room_id,
-                roomName: groupCallState.roomSummary.name ?? "",
-                roomAvatar: groupCallState.roomSummary.avatar_url ?? null,
-                e2eeSystem: {
-                  kind: groupCallState.roomSummary[
-                    "im.nheko.summary.encryption"
-                  ]
-                    ? E2eeType.PER_PARTICIPANT
-                    : E2eeType.NONE,
-                },
-              }}
-              onEnter={(): void => knock?.()}
-              enterLabel={label}
-              waitingForInvite={groupCallState.kind === "waitForInvite"}
-              confineToRoom={confineToRoom}
-              hideHeader={header !== "standard"}
-              participantCount={null}
-              muteStates={muteStates}
-              onShareClick={null}
-            />
-          )
+          <KnockLobbyView
+            client={client!}
+            roomSummary={groupCallState.roomSummary}
+            profile={{
+              displayName: userDisplayName ?? "",
+              avatarUrl: avatarUrl ?? "",
+            }}
+            knock={
+              groupCallState.kind === "canKnock" ? groupCallState.knock : null
+            }
+            confineToRoom={confineToRoom}
+            hideHeader={header !== "standard"}
+          />
         );
       }
       case "loading":