Show error screens in group calls (#29254)

* Avoid destroying calls until they are hidden from the UI

We often want calls to exist even when no more participants are left in the MatrixRTC session. So, we should avoid destroying calls as long as they're being presented in the UI; this means that the user has an intent to either join the call or continue looking at an error screen, and we shouldn't interrupt that interaction.

The RoomViewStore is now what takes care of creating and destroying calls, rather than the CallView. In general it seems kinda impossible to safely create and destroy model objects from React lifecycle hooks, so moving this responsibility to a store seemed appropriate and resolves existing issues with calls in React strict mode.

* Wait for a close action before closing a call

This creates a distinction between the user hanging up and the widget being ready to close, which is useful for allowing Element Call to show error screens when disconnected from the call, for example.

* Don't expect a 'close' action in video rooms

These use the returnToLobby option and are expected to remain visible when the user leaves the call.

src/stores/RoomViewStore.tsx

@@ -50,6 +50,8 @@ import { type CancelAskToJoinPayload } from "../dispatcher/payloads/CancelAskToJ
 import { type SubmitAskToJoinPayload } from "../dispatcher/payloads/SubmitAskToJoinPayload";
 import { ModuleRunner } from "../modules/ModuleRunner";
 import { setMarkedUnreadState } from "../utils/notifications";
+import { ConnectionState, ElementCall } from "../models/Call";
+import { isVideoRoom } from "../utils/video-rooms";
 
 const NUM_JOIN_RETRY = 5;
 
@@ -353,6 +355,23 @@ export class RoomViewStore extends EventEmitter {
                 });
             }
 
+            if (room && (payload.view_call || isVideoRoom(room))) {
+                let call = CallStore.instance.getCall(payload.room_id);
+                // Start a call if not already there
+                if (call === null) {
+                    ElementCall.create(room, false);
+                    call = CallStore.instance.getCall(payload.room_id)!;
+                }
+                call.presented = true;
+                // Immediately start the call. This will connect to all required widget events
+                // and allow the widget to show the lobby.
+                if (call.connectionState === ConnectionState.Disconnected) call.start();
+            }
+            // If we switch to a different room from the call, we are no longer presenting it
+            const prevRoomCall = this.state.roomId ? CallStore.instance.getCall(this.state.roomId) : null;
+            if (prevRoomCall !== null && (!payload.view_call || payload.room_id !== this.state.roomId))
+                prevRoomCall.presented = false;
+
             if (SettingsStore.getValue("feature_sliding_sync") && this.state.roomId !== payload.room_id) {
                 if (this.state.subscribingRoomId && this.state.subscribingRoomId !== payload.room_id) {
                     // unsubscribe from this room, but don't await it as we don't care when this gets done.

src/stores/widgets/ElementWidgetActions.ts

@@ -12,6 +12,7 @@ export enum ElementWidgetActions {
     // All of these actions are currently specific to Jitsi and Element Call
     JoinCall = "io.element.join",
     HangupCall = "im.vector.hangup",
+    Close = "io.element.close",
     CallParticipants = "io.element.participants",
     StartLiveStream = "im.vector.start_live_stream",
 

src/stores/widgets/WidgetMessagingStore.ts

@@ -72,8 +72,11 @@ export class WidgetMessagingStore extends AsyncStoreWithClient<EmptyObject> {
      * @param {string} widgetUid The widget UID.
      */
     public stopMessagingByUid(widgetUid: string): void {
-        this.widgetMap.remove(widgetUid)?.stop();
-        this.emit(WidgetMessagingStoreEvent.StopMessaging, widgetUid);
+        const messaging = this.widgetMap.remove(widgetUid);
+        if (messaging !== undefined) {
+            messaging.stop();
+            this.emit(WidgetMessagingStoreEvent.StopMessaging, widgetUid);
+        }
     }
 
     /**