Initial SpaceTreeLevelLayoutStore implementation

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/stores/SpaceTreeLevelLayoutStore.ts

@@ -0,0 +1,32 @@
+/*
+Copyright 2021 Šimon Brandner <simon.bra.ag@gmail.com>
+
+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";
+
+const getSpaceCollapsedKey = (space: Room) => `mx_space_collapsed_${space.roomId}`;
+
+export default class SpaceTreeLevelLayoutStore {
+    public static setSpaceCollapsedState(space: Room, collapsed: boolean) {
+        // XXX: localStorage doesn't allow booleans
+        localStorage.setItem(getSpaceCollapsedKey(space), collapsed.toString());
+    }
+
+    public static getSpaceCollapsedState(space: Room, fallback: boolean): boolean {
+        const collapsedLocalStorage = localStorage.getItem(getSpaceCollapsedKey(space));
+        // XXX: localStorage doesn't allow booleans
+        return collapsedLocalStorage ? collapsedLocalStorage === "true" : fallback;
+    }
+}