Have LocalEchoWrapper emit updates so the app can react faster

src/settings/SettingsStore.ts

@@ -28,7 +28,7 @@ import { _t } from '../languageHandler';
 import dis from '../dispatcher/dispatcher';
 import { IFeature, ISetting, LabGroup, SETTINGS } from "./Settings";
 import LocalEchoWrapper from "./handlers/LocalEchoWrapper";
-import { WatchManager, CallbackFn as WatchCallbackFn } from "./WatchManager";
+import { CallbackFn as WatchCallbackFn, WatchManager } from "./WatchManager";
 import { SettingLevel } from "./SettingLevel";
 import SettingsHandler from "./handlers/SettingsHandler";
 import { SettingUpdatedPayload } from "../dispatcher/payloads/SettingUpdatedPayload";
@@ -50,21 +50,20 @@ for (const key of Object.keys(SETTINGS)) {
     }
 }
 
+// Only wrap the handlers with async setters in a local echo wrapper
 const LEVEL_HANDLERS = {
     [SettingLevel.DEVICE]: new DeviceSettingsHandler(featureNames, defaultWatchManager),
     [SettingLevel.ROOM_DEVICE]: new RoomDeviceSettingsHandler(defaultWatchManager),
-    [SettingLevel.ROOM_ACCOUNT]: new RoomAccountSettingsHandler(defaultWatchManager),
-    [SettingLevel.ACCOUNT]: new AccountSettingsHandler(defaultWatchManager),
-    [SettingLevel.ROOM]: new RoomSettingsHandler(defaultWatchManager),
+    [SettingLevel.ROOM_ACCOUNT]: new LocalEchoWrapper(
+        new RoomAccountSettingsHandler(defaultWatchManager),
+        SettingLevel.ROOM_ACCOUNT,
+    ),
+    [SettingLevel.ACCOUNT]: new LocalEchoWrapper(new AccountSettingsHandler(defaultWatchManager), SettingLevel.ACCOUNT),
+    [SettingLevel.ROOM]: new LocalEchoWrapper(new RoomSettingsHandler(defaultWatchManager), SettingLevel.ROOM),
     [SettingLevel.CONFIG]: new ConfigSettingsHandler(featureNames),
     [SettingLevel.DEFAULT]: new DefaultSettingsHandler(defaultSettings, invertedDefaultSettings),
 };
 
-// Wrap all the handlers with local echo
-for (const key of Object.keys(LEVEL_HANDLERS)) {
-    LEVEL_HANDLERS[key] = new LocalEchoWrapper(LEVEL_HANDLERS[key]);
-}
-
 export const LEVEL_ORDER = [
     SettingLevel.DEVICE,
     SettingLevel.ROOM_DEVICE,

src/settings/handlers/AccountSettingsHandler.ts

@@ -36,10 +36,14 @@ const ANALYTICS_EVENT_TYPE = "im.vector.analytics";
  * This handler does not make use of the roomId parameter.
  */
 export default class AccountSettingsHandler extends MatrixClientBackedSettingsHandler {
-    constructor(private watchers: WatchManager) {
+    constructor(public readonly watchers: WatchManager) {
         super();
     }
 
+    public get level(): SettingLevel {
+        return SettingLevel.ACCOUNT;
+    }
+
     public initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient) {
         if (oldClient) {
             oldClient.removeListener("accountData", this.onAccountData);

src/settings/handlers/DeviceSettingsHandler.ts

@@ -33,7 +33,7 @@ export default class DeviceSettingsHandler extends SettingsHandler {
      * @param {string[]} featureNames The names of known features.
      * @param {WatchManager} watchers The watch manager to notify updates to
      */
-    constructor(private featureNames: string[], private watchers: WatchManager) {
+    constructor(private featureNames: string[], public readonly watchers: WatchManager) {
         super();
     }
 

src/settings/handlers/LocalEchoWrapper.ts

@@ -16,6 +16,7 @@ limitations under the License.
 */
 
 import SettingsHandler from "./SettingsHandler";
+import { SettingLevel } from "../SettingLevel";
 
 /**
  * A wrapper for a SettingsHandler that performs local echo on
@@ -32,8 +33,9 @@ export default class LocalEchoWrapper extends SettingsHandler {
     /**
      * Creates a new local echo wrapper
      * @param {SettingsHandler} handler The handler to wrap
+     * @param {SettingLevel} level The level to notify updates at
      */
-    constructor(private handler: SettingsHandler) {
+    constructor(private readonly handler: SettingsHandler, private readonly level: SettingLevel) {
         super();
     }
 
@@ -54,8 +56,13 @@ export default class LocalEchoWrapper extends SettingsHandler {
         const cacheRoomId = roomId ? roomId : "UNDEFINED"; // avoid weird keys
         bySetting[cacheRoomId] = newValue;
 
+        const currentValue = this.handler.getValue(settingName, roomId);
         const handlerPromise = this.handler.setValue(settingName, roomId, newValue);
-        return Promise.resolve(handlerPromise).finally(() => {
+        this.handler.watchers?.notifyUpdate(settingName, roomId, this.level, newValue);
+        return Promise.resolve(handlerPromise).catch(() => {
+            // notify of a rollback
+            this.handler.watchers?.notifyUpdate(settingName, roomId, this.level, currentValue);
+        }).finally(() => {
             delete bySetting[cacheRoomId];
         });
     }

src/settings/handlers/RoomAccountSettingsHandler.ts

@@ -31,7 +31,7 @@ const ALLOWED_WIDGETS_EVENT_TYPE = "im.vector.setting.allowed_widgets";
  * Gets and sets settings at the "room-account" level for the current user.
  */
 export default class RoomAccountSettingsHandler extends MatrixClientBackedSettingsHandler {
-    constructor(private watchers: WatchManager) {
+    constructor(public readonly watchers: WatchManager) {
         super();
     }
 

src/settings/handlers/RoomDeviceSettingsHandler.ts

@@ -24,7 +24,7 @@ import { WatchManager } from "../WatchManager";
  * room.
  */
 export default class RoomDeviceSettingsHandler extends SettingsHandler {
-    constructor(private watchers: WatchManager) {
+    constructor(public readonly watchers: WatchManager) {
         super();
     }
 

src/settings/handlers/RoomSettingsHandler.ts

@@ -29,7 +29,7 @@ import { WatchManager } from "../WatchManager";
  * Gets and sets settings at the "room" level.
  */
 export default class RoomSettingsHandler extends MatrixClientBackedSettingsHandler {
-    constructor(private watchers: WatchManager) {
+    constructor(public readonly watchers: WatchManager) {
         super();
     }
 

src/settings/handlers/SettingsHandler.ts

@@ -15,11 +15,15 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { WatchManager } from "../WatchManager";
+
 /**
  * Represents the base class for all level handlers. This class performs no logic
  * and should be overridden.
  */
 export default abstract class SettingsHandler {
+    public readonly watchers?: WatchManager;
+
     /**
      * Gets the value for a particular setting at this level for a particular room.
      * If no room is applicable, the roomId may be null. The roomId may not be