Add Space Panel with Room List filtering

src/stores/room-list/SpaceWatcher.ts

@@ -0,0 +1,39 @@
+/*
+Copyright 2021 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 { Room } from "matrix-js-sdk/src/models/room";
+
+import { RoomListStoreClass } from "./RoomListStore";
+import { SpaceFilterCondition } from "./filters/SpaceFilterCondition";
+import SpaceStore, { UPDATE_SELECTED_SPACE } from "../SpaceStore";
+
+/**
+ * Watches for changes in spaces to manage the filter on the provided RoomListStore
+ */
+export class SpaceWatcher {
+    private filter = new SpaceFilterCondition();
+    private activeSpace: Room = SpaceStore.instance.activeSpace;
+
+    constructor(private store: RoomListStoreClass) {
+        this.filter.updateSpace(this.activeSpace); // get the filter into a consistent state
+        store.addFilter(this.filter);
+        SpaceStore.instance.on(UPDATE_SELECTED_SPACE, this.onSelectedSpaceUpdated);
+    }
+
+    private onSelectedSpaceUpdated = (activeSpace) => {
+        this.filter.updateSpace(this.activeSpace = activeSpace);
+    };
+}