New Room List: Create new labs flag

src/components/structures/LeftPanel.tsx

@@ -36,6 +36,8 @@ import AccessibleButton, { type ButtonEvent } from "../views/elements/Accessible
 import PosthogTrackers from "../../PosthogTrackers";
 import type PageType from "../../PageTypes";
 import { Landmark, LandmarkNavigation } from "../../accessibility/LandmarkNavigation";
+import SettingsStore from "../../settings/SettingsStore";
+import { NewRoomListView } from "../views/rooms/NewRoomListView";
 
 interface IProps {
     isMinimized: boolean;
@@ -377,6 +379,23 @@ export default class LeftPanel extends React.Component<IProps, IState> {
     }
 
     public render(): React.ReactNode {
+        const containerClasses = classNames({
+            mx_LeftPanel: true,
+            mx_LeftPanel_minimized: this.props.isMinimized,
+        });
+
+        const roomListClasses = classNames("mx_LeftPanel_actualRoomListContainer", "mx_AutoHideScrollbar");
+        const useNewRoomList = SettingsStore.getValue("feature_new_room_list");
+        if (useNewRoomList) {
+            return (
+                <div className={containerClasses}>
+                    <div className="mx_LeftPanel_roomListContainer">
+                        <NewRoomListView />
+                    </div>
+                </div>
+            );
+        }
+
         const roomList = (
             <RoomList
                 onKeyDown={this.onKeyDown}
@@ -391,13 +410,6 @@ export default class LeftPanel extends React.Component<IProps, IState> {
             />
         );
 
-        const containerClasses = classNames({
-            mx_LeftPanel: true,
-            mx_LeftPanel_minimized: this.props.isMinimized,
-        });
-
-        const roomListClasses = classNames("mx_LeftPanel_actualRoomListContainer", "mx_AutoHideScrollbar");
-
         return (
             <div className={containerClasses}>
                 <div className="mx_LeftPanel_roomListContainer">

src/components/views/rooms/NewRoomListView.tsx

@@ -0,0 +1,14 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import React from "react";
+
+type IProps = unknown;
+
+export const NewRoomListView: React.FC<IProps> = (props: IProps) => {
+    return <div>New Room List</div>;
+};

src/i18n/strings/en_EN.json

@@ -1499,6 +1499,7 @@
         "location_share_live_description": "Temporary implementation. Locations persist in room history.",
         "mjolnir": "New ways to ignore people",
         "msc3531_hide_messages_pending_moderation": "Let moderators hide messages pending moderation.",
+        "new_room_list": "Enable new room list",
         "notification_settings": "New Notification Settings",
         "notification_settings_beta_caption": "Introducing a simpler way to change your notification settings. Customize your %(brand)s, just the way you like.",
         "notification_settings_beta_title": "Notification Settings",

src/settings/Settings.tsx

@@ -205,6 +205,7 @@ export interface Settings {
     "feature_location_share_live": IFeature;
     "feature_dynamic_room_predecessors": IFeature;
     "feature_render_reaction_images": IFeature;
+    "feature_new_room_list": IFeature;
     "feature_ask_to_join": IFeature;
     "feature_notifications": IFeature;
     // These are in the feature namespace but aren't actually features
@@ -623,6 +624,14 @@ export const SETTINGS: Settings = {
         supportedLevelsAreOrdered: true,
         default: false,
     },
+    "feature_new_room_list": {
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS_WITH_CONFIG_PRIORITISED,
+        labsGroup: LabGroup.Ui,
+        displayName: _td("labs|new_room_list"),
+        description: _td("labs|under_active_development"),
+        isFeature: true,
+        default: false,
+    },
     /**
      * With the transition to Compound we are moving to a base font size
      * of 16px. We're taking the opportunity to move away from the `baseFontSize`