refactor extract inner classes to their own files

src/state/ScreenShare.ts

@@ -0,0 +1,54 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+import { ObservableScope } from "./ObservableScope.ts";
+import { ScreenShareViewModel } from "./MediaViewModel.ts";
+import { BehaviorSubject, type Observable } from "rxjs";
+import {
+  LocalParticipant,
+  RemoteParticipant,
+  type Room as LivekitRoom,
+} from "livekit-client";
+import type { RoomMember } from "matrix-js-sdk";
+import type { EncryptionSystem } from "../e2ee/sharedKeyManagement.ts";
+import type { Behavior } from "./Behavior.ts";
+
+// TODO Document this
+export class ScreenShare {
+  private readonly scope = new ObservableScope();
+  public readonly vm: ScreenShareViewModel;
+  private readonly participant$: BehaviorSubject<
+    LocalParticipant | RemoteParticipant
+  >;
+
+  public constructor(
+    id: string,
+    member: RoomMember,
+    participant: LocalParticipant | RemoteParticipant,
+    encryptionSystem: EncryptionSystem,
+    livekitRoom: LivekitRoom,
+    pretendToBeDisconnected$: Behavior<boolean>,
+    displayName$: Observable<string>,
+  ) {
+    this.participant$ = new BehaviorSubject(participant);
+
+    this.vm = new ScreenShareViewModel(
+      id,
+      member,
+      this.participant$.asObservable(),
+      encryptionSystem,
+      livekitRoom,
+      pretendToBeDisconnected$,
+      this.scope.behavior(displayName$),
+      participant.isLocal,
+    );
+  }
+
+  public destroy(): void {
+    this.scope.end();
+    this.vm.destroy();
+  }
+}