Fix some features not being configurable via features (#10276)

src/settings/controllers/ServerSupportUnstableFeatureController.ts

@@ -0,0 +1,77 @@
+/*
+Copyright 2023 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 { MatrixClient } from "matrix-js-sdk/src/matrix";
+
+import { SettingLevel } from "../SettingLevel";
+import MatrixClientBackedController from "./MatrixClientBackedController";
+import { WatchManager } from "../WatchManager";
+import SettingsStore from "../SettingsStore";
+
+/**
+ * Disables a given setting if the server unstable feature it requires is not supported
+ * When a setting gets disabled or enabled from this controller it notifies the given WatchManager
+ */
+export default class ServerSupportUnstableFeatureController extends MatrixClientBackedController {
+    private enabled: boolean | undefined;
+
+    public constructor(
+        private readonly settingName: string,
+        private readonly watchers: WatchManager,
+        private readonly unstableFeatures: string[],
+        private readonly forcedValue: any = false,
+    ) {
+        super();
+    }
+
+    public get disabled(): boolean {
+        return !this.enabled;
+    }
+
+    public set disabled(v: boolean) {
+        if (!v === this.enabled) return;
+        this.enabled = !v;
+        const level = SettingsStore.firstSupportedLevel(this.settingName);
+        const settingValue = SettingsStore.getValue(this.settingName, null);
+        this.watchers.notifyUpdate(this.settingName, null, level, settingValue);
+    }
+
+    protected async initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient): Promise<void> {
+        this.disabled = true;
+        let supported = true;
+        for (const feature of this.unstableFeatures) {
+            supported = await this.client.doesServerSupportUnstableFeature(feature);
+            if (!supported) break;
+        }
+        this.disabled = !supported;
+    }
+
+    public getValueOverride(
+        level: SettingLevel,
+        roomId: string,
+        calculatedValue: any,
+        calculatedAtLevel: SettingLevel | null,
+    ): any {
+        if (this.settingDisabled) {
+            return this.forcedValue;
+        }
+        return null; // no override
+    }
+
+    public get settingDisabled(): boolean {
+        return this.disabled;
+    }
+}