Add a UI feature to disable advanced encryption options

src/components/views/settings/E2eAdvancedPanel.js

@@ -19,6 +19,7 @@ import React from 'react';
 import * as sdk from '../../../index';
 import {_t} from "../../../languageHandler";
 import {SettingLevel} from "../../../settings/SettingLevel";
+import SettingsStore from "../../../settings/SettingsStore";
 
 const SETTING_MANUALLY_VERIFY_ALL_SESSIONS = "e2ee.manuallyVerifyAllSessions";
 
@@ -37,3 +38,7 @@ const E2eAdvancedPanel = props => {
 };
 
 export default E2eAdvancedPanel;
+
+export function isE2eAdvancedPanelPossible(): boolean {
+    return SettingsStore.isEnabled(SETTING_MANUALLY_VERIFY_ALL_SESSIONS);
+}

src/components/views/settings/tabs/room/SecurityRoomSettingsTab.js

@@ -24,6 +24,7 @@ import Modal from "../../../../../Modal";
 import QuestionDialog from "../../../dialogs/QuestionDialog";
 import StyledRadioGroup from '../../../elements/StyledRadioGroup';
 import {SettingLevel} from "../../../../../settings/SettingLevel";
+import SettingsStore from "../../../../../settings/SettingsStore";
 
 export default class SecurityRoomSettingsTab extends React.Component {
     static propTypes = {
@@ -340,10 +341,13 @@ export default class SecurityRoomSettingsTab extends React.Component {
         const canEnableEncryption = !isEncrypted && hasEncryptionPermission;
 
         let encryptionSettings = null;
-        if (isEncrypted) {
-            encryptionSettings = <SettingsFlag name="blacklistUnverifiedDevices" level={SettingLevel.ROOM_DEVICE}
+        if (isEncrypted && SettingsStore.isEnabled("blacklistUnverifiedDevices")) {
+            encryptionSettings = <SettingsFlag
+                name="blacklistUnverifiedDevices"
+                level={SettingLevel.ROOM_DEVICE}
                 onChange={this._updateBlacklistDevicesFlag}
-                                               roomId={this.props.roomId} />;
+                roomId={this.props.roomId}
+            />;
         }
 
         return (

src/components/views/settings/tabs/user/SecurityUserSettingsTab.js

@@ -32,6 +32,7 @@ import {SettingLevel} from "../../../../../settings/SettingLevel";
 import SecureBackupPanel from "../../SecureBackupPanel";
 import SettingsStore from "../../../../../settings/SettingsStore";
 import {UIFeature} from "../../../../../settings/UIFeature";
+import {isE2eAdvancedPanelPossible} from "../../E2eAdvancedPanel";
 
 export class IgnoredUser extends React.Component {
     static propTypes = {
@@ -219,6 +220,15 @@ export default class SecurityUserSettingsTab extends React.Component {
             );
         }
 
+        let noSendUnverifiedSetting;
+        if (SettingsStore.isEnabled("blacklistUnverifiedDevices")) {
+            noSendUnverifiedSetting = <SettingsFlag
+                name='blacklistUnverifiedDevices'
+                level={SettingLevel.DEVICE}
+                onChange={this._updateBlacklistDevicesFlag}
+            />;
+        }
+
         return (
             <div className='mx_SettingsTab_section'>
                 <span className='mx_SettingsTab_subheading'>{_t("Cryptography")}</span>
@@ -233,8 +243,7 @@ export default class SecurityUserSettingsTab extends React.Component {
                     </li>
                 </ul>
                 {importExportButtons}
-                <SettingsFlag name='blacklistUnverifiedDevices' level={SettingLevel.DEVICE}
-                              onChange={this._updateBlacklistDevicesFlag} />
+                {noSendUnverifiedSetting}
             </div>
         );
     }
@@ -355,15 +364,21 @@ export default class SecurityUserSettingsTab extends React.Component {
         const E2eAdvancedPanel = sdk.getComponent('views.settings.E2eAdvancedPanel');
         let advancedSection;
         if (SettingsStore.getValue(UIFeature.AdvancedSettings)) {
+            const ignoreUsersPanel = this._renderIgnoredUsers();
+            const invitesPanel = this._renderManageInvites();
+            const e2ePanel = isE2eAdvancedPanelPossible() ? <E2eAdvancedPanel /> : null;
+            // only show the section if there's something to show
+            if (ignoreUsersPanel || invitesPanel || e2ePanel) {
                 advancedSection = <>
                     <div className="mx_SettingsTab_heading">{_t("Advanced")}</div>
                     <div className="mx_SettingsTab_section">
-                    {this._renderIgnoredUsers()}
-                    {this._renderManageInvites()}
-                    <E2eAdvancedPanel />
+                        {ignoreUsersPanel}
+                        {invitesPanel}
+                        {e2ePanel}
                     </div>
                 </>;
             }
+        }
 
         return (
             <div className="mx_SettingsTab mx_SecurityUserSettingsTab">

src/settings/Settings.ts

@@ -34,6 +34,7 @@ import SettingController from "./controllers/SettingController";
 import { RightPanelPhases } from "../stores/RightPanelStorePhases";
 import UIFeatureController from "./controllers/UIFeatureController";
 import { UIFeature } from "./UIFeature";
+import { OrderedMultiController } from "./controllers/OrderedMultiController";
 
 // These are just a bunch of helper arrays to avoid copy/pasting a bunch of times
 const LEVELS_ROOM_SETTINGS = [
@@ -436,6 +437,7 @@ export const SETTINGS: {[setting: string]: ISetting} = {
             "room-device": _td('Never send encrypted messages to unverified sessions in this room from this session'),
         },
         default: false,
+        controller: new UIFeatureController(UIFeature.AdvancedEncryption),
     },
     "urlPreviewsEnabled": {
         supportedLevels: LEVELS_ROOM_SETTINGS_WITH_ROOM,
@@ -591,9 +593,15 @@ export const SETTINGS: {[setting: string]: ISetting} = {
         supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
         displayName: _td("Manually verify all remote sessions"),
         default: false,
-        controller: new PushToMatrixClientController(
+        controller: new OrderedMultiController([
+            // Apply the feature controller first to ensure that the setting doesn't
+            // show up and can't be toggled. PushToMatrixClientController doesn't
+            // do any overrides anyways.
+            new UIFeatureController(UIFeature.AdvancedEncryption),
+            new PushToMatrixClientController(
                 MatrixClient.prototype.setCryptoTrustCrossSignedDevices, true,
             ),
+        ]),
     },
     "ircDisplayNameWidth": {
         // We specifically want to have room-device > device so that users may set a device default
@@ -612,6 +620,10 @@ export const SETTINGS: {[setting: string]: ISetting} = {
         supportedLevels: LEVELS_ROOM_OR_ACCOUNT,
         default: {},
     },
+    [UIFeature.AdvancedEncryption]: {
+        supportedLevels: LEVELS_UI_FEATURE,
+        default: true,
+    },
     [UIFeature.URLPreviews]: {
         supportedLevels: LEVELS_UI_FEATURE,
         default: true,

src/settings/UIFeature.ts

@@ -16,6 +16,7 @@ limitations under the License.
 
 // see settings.md for documentation on conventions
 export enum UIFeature {
+    AdvancedEncryption = "UIFeature.advancedEncryption",
     URLPreviews = "UIFeature.urlPreviews",
     Widgets = "UIFeature.widgets",
     Voip = "UIFeature.voip",

src/settings/controllers/OrderedMultiController.ts

@@ -0,0 +1,54 @@
+/*
+Copyright 2020 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";
+
+/**
+ * Allows for multiple controllers to affect a setting. The first controller
+ * provided to this class which overrides the setting value will affect
+ * the value - other controllers are not called. Change notification handlers
+ * are proxied through to all controllers.
+ *
+ * Similarly, the first controller which indicates that a setting is disabled
+ * will be used - other controllers will not be considered.
+ */
+export class OrderedMultiController extends SettingController {
+    constructor(public readonly controllers: SettingController[]) {
+        super();
+    }
+
+    public getValueOverride(level: SettingLevel, roomId: string, calculatedValue: any, calculatedAtLevel: SettingLevel): any {
+        for (const controller of this.controllers) {
+            const override = controller.getValueOverride(level, roomId, calculatedValue, calculatedAtLevel);
+            if (override !== undefined && override !== null) return override;
+        }
+        return null; // no override
+    }
+
+    public onChange(level: SettingLevel, roomId: string, newValue: any) {
+        for (const controller of this.controllers) {
+            controller.onChange(level, roomId, newValue);
+        }
+    }
+
+    public get settingDisabled(): boolean {
+        for (const controller of this.controllers) {
+            if (controller.settingDisabled) return true;
+        }
+        return false;
+    }
+}