Element Call video rooms (#9267)

* Add an element_call_url config option

* Add a labs flag for Element Call video rooms

* Add Element Call as another video rooms backend

* Consolidate event power level defaults

* Remember to clean up participantsExpirationTimer

* Fix a code smell

* Test the clean method

* Fix some strict mode errors

* Test that clean still works when there are no state events

* Test auto-approval of Element Call widget capabilities

* Deduplicate some code to placate SonarCloud

* Fix more strict mode errors

* Test that calls disconnect when leaving the room

* Test the get methods of JitsiCall and ElementCall more

* Test Call.ts even more

* Test creation of Element video rooms

* Test that createRoom works for non-video-rooms

* Test Call's get method rather than the methods of derived classes

* Ensure that the clean method is able to preserve devices

* Remove duplicate clean method

* Fix lints

* Fix some strict mode errors in RoomPreviewCard

* Test RoomPreviewCard changes

* Quick and dirty hotfix for the community testing session

* Revert "Quick and dirty hotfix for the community testing session"

This reverts commit 37056514fbc040aaf1bff2539da770a1c8ba72a2.

* Fix the event schema for org.matrix.msc3401.call.member devices

* Remove org.matrix.call_duplicate_session from Element Call capabilities

It's no longer used by Element Call when running as a widget.

* Replace element_call_url with a map

* Make PiPs work for virtual widgets

* Auto-approve room timeline capability

Because Element Call uses this now

* Create a reusable isVideoRoom util

src/stores/WidgetStore.ts

@@ -30,11 +30,11 @@ import WidgetUtils from "../utils/WidgetUtils";
 import { WidgetType } from "../widgets/WidgetType";
 import { UPDATE_EVENT } from "./AsyncStore";
 
-interface IState {}
+interface IState { }
 
 export interface IApp extends IWidget {
     roomId: string;
-    eventId: string;
+    eventId?: string; // not present on virtual widgets
     // eslint-disable-next-line camelcase
     avatar_url?: string; // MSC2765 https://github.com/matrix-org/matrix-doc/pull/2765
 }
@@ -118,7 +118,12 @@ export default class WidgetStore extends AsyncStoreWithClient<IState> {
         // otherwise we are out of sync with the rest of the app with stale widget events during removal
         Array.from(this.widgetMap.values()).forEach(app => {
             if (app.roomId !== room.roomId) return; // skip - wrong room
-            this.widgetMap.delete(WidgetUtils.getWidgetUid(app));
+            if (app.eventId === undefined) {
+                // virtual widget - keep it
+                roomInfo.widgets.push(app);
+            } else {
+                this.widgetMap.delete(WidgetUtils.getWidgetUid(app));
+            }
         });
 
         let edited = false;
@@ -169,16 +174,38 @@ export default class WidgetStore extends AsyncStoreWithClient<IState> {
         this.emit(UPDATE_EVENT, roomId);
     };
 
-    public getRoom = (roomId: string, initIfNeeded = false) => {
+    public get(widgetId: string, roomId: string | undefined): IApp | undefined {
+        return this.widgetMap.get(WidgetUtils.calcWidgetUid(widgetId, roomId));
+    }
+
+    public getRoom(roomId: string, initIfNeeded = false): IRoomWidgets {
         if (initIfNeeded) this.initRoom(roomId); // internally handles "if needed"
-        return this.roomMap.get(roomId);
-    };
+        return this.roomMap.get(roomId)!;
+    }
 
     public getApps(roomId: string): IApp[] {
         const roomInfo = this.getRoom(roomId);
         return roomInfo?.widgets || [];
     }
 
+    public addVirtualWidget(widget: IWidget, roomId: string): IApp {
+        this.initRoom(roomId);
+        const app = WidgetUtils.makeAppConfig(widget.id, widget, widget.creatorUserId, roomId, undefined);
+        this.widgetMap.set(WidgetUtils.getWidgetUid(app), app);
+        this.roomMap.get(roomId)!.widgets.push(app);
+        return app;
+    }
+
+    public removeVirtualWidget(widgetId: string, roomId: string): void {
+        this.widgetMap.delete(WidgetUtils.calcWidgetUid(widgetId, roomId));
+        const roomApps = this.roomMap.get(roomId);
+        if (roomApps) {
+            roomApps.widgets = roomApps.widgets.filter(app =>
+                !(app.id === widgetId && app.roomId === roomId),
+            );
+        }
+    }
+
     public doesRoomHaveConference(room: Room): boolean {
         const roomInfo = this.getRoom(room.roomId);
         if (!roomInfo) return false;