Add new layout switcher UI

Co-authored-by: Quirin Götz <codeworks@supercable.onl>

src/settings/controllers/NewLayoutSwitcherController.ts

@@ -0,0 +1,26 @@
+/*
+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 SettingController from "./SettingController";
+import { SettingLevel } from "../SettingLevel";
+import SettingsStore from "../SettingsStore";
+import { Layout } from "../Layout";
+
+export default class NewLayoutSwitcherController extends SettingController {
+    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+        // On disabling switch back to Layout.Group if Layout.Bubble
+        if (!newValue && SettingsStore.getValue("layout") == Layout.Bubble) {
+            SettingsStore.setValue("layout", null, SettingLevel.DEVICE, Layout.Group);
+        }
+    }
+}