Step 8.5: Isolate RightPanelStore from RoomViewStore

src/dispatcher/actions.ts

@@ -259,4 +259,10 @@ export enum Action {
      * Fired when clicking user name from group view
      */
     ViewStartChatOrReuse = "view_start_chat_or_reuse",
+
+    /**
+     * Fired when the user's active room changed, possibly from/to a non-room view.
+     * Payload: ActiveRoomChangedPayload
+     */
+    ActiveRoomChanged = "active_room_changed",
 }

src/dispatcher/payloads/ActiveRoomChangedPayload.ts

@@ -0,0 +1,27 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Optional } from "matrix-events-sdk";
+
+import { Action } from "../actions";
+import { ActionPayload } from "../payloads";
+
+export interface ActiveRoomChangedPayload extends ActionPayload {
+    action: Action.ActiveRoomChanged;
+
+    oldRoomId: Optional<string>;
+    newRoomId: Optional<string>;
+}