Connection lost banner (#1101)

* connection lost banner
if there is no connection to the home server

Signed-off-by: Timo K <toger5@hotmail.de>

public/locales/en-GB/app.json

@@ -36,6 +36,7 @@
   "Close": "Close",
   "Confirm password": "Confirm password",
   "Connection lost": "Connection lost",
+  "Connectivity to the server has been lost.": "Connectivity to the server has been lost.",
   "Copied!": "Copied!",
   "Copy": "Copy",
   "Copy and share this call link": "Copy and share this call link",

src/App.tsx

@@ -29,6 +29,7 @@ import { usePageFocusStyle } from "./usePageFocusStyle";
 import { SequenceDiagramViewerPage } from "./SequenceDiagramViewerPage";
 import { InspectorContextProvider } from "./room/GroupCallInspector";
 import { CrashView, LoadingView } from "./FullScreenView";
+import { DisconnectedBanner } from "./DisconnectedBanner";
 import { Initializer } from "./initializer";
 import { MediaHandlerProvider } from "./settings/useMediaHandler";
 
@@ -60,6 +61,7 @@ export default function App({ history }: AppProps) {
               <InspectorContextProvider>
                 <Sentry.ErrorBoundary fallback={errorPage}>
                   <OverlayProvider>
+                    <DisconnectedBanner />
                     <Switch>
                       <SentryRoute exact path="/">
                         <HomePage />

src/ClientContext.tsx

@@ -25,9 +25,10 @@ import React, {
   useRef,
 } from "react";
 import { useHistory } from "react-router-dom";
-import { MatrixClient } from "matrix-js-sdk/src/client";
+import { ClientEvent, MatrixClient } from "matrix-js-sdk/src/client";
 import { logger } from "matrix-js-sdk/src/logger";
 import { useTranslation } from "react-i18next";
+import { ISyncStateData, SyncState } from "matrix-js-sdk/src/sync";
 
 import { ErrorView } from "./FullScreenView";
 import {
@@ -70,6 +71,8 @@ const loadSession = (): Session => {
 const saveSession = (session: Session) =>
   localStorage.setItem("matrix-auth-store", JSON.stringify(session));
 const clearSession = () => localStorage.removeItem("matrix-auth-store");
+const isDisconnected = (syncState, syncData) =>
+  syncState === "ERROR" && syncData?.error?.name === "ConnectionError";
 
 interface ClientState {
   loading: boolean;
@@ -81,6 +84,7 @@ interface ClientState {
   logout: () => void;
   setClient: (client: MatrixClient, session: Session) => void;
   error?: Error;
+  disconnected: boolean;
 }
 
 const ClientContext = createContext<ClientState>(null);
@@ -98,7 +102,15 @@ export const ClientProvider: FC<Props> = ({ children }) => {
   const history = useHistory();
   const initializing = useRef(false);
   const [
-    { loading, isAuthenticated, isPasswordlessUser, client, userName, error },
+    {
+      loading,
+      isAuthenticated,
+      isPasswordlessUser,
+      client,
+      userName,
+      error,
+      disconnected,
+    },
     setState,
   ] = useState<ClientProviderState>({
     loading: true,
@@ -107,8 +119,18 @@ export const ClientProvider: FC<Props> = ({ children }) => {
     client: undefined,
     userName: null,
     error: undefined,
+    disconnected: false,
   });
 
+  const onSync = (state: SyncState, _old: SyncState, data: ISyncStateData) => {
+    setState((currentState) => {
+      const disconnected = isDisconnected(state, data);
+      return disconnected === currentState.disconnected
+        ? currentState
+        : { ...currentState, disconnected };
+    });
+  };
+
   useEffect(() => {
     // In case the component is mounted, unmounted, and remounted quickly (as
     // React does in strict mode), we need to make sure not to doubly initialize
@@ -183,9 +205,10 @@ export const ClientProvider: FC<Props> = ({ children }) => {
         }
       }
     };
-
+    let clientWithListener: MatrixClient;
     init()
       .then(({ client, isPasswordlessUser }) => {
+        clientWithListener = client;
         setState({
           client,
           loading: false,
@@ -193,7 +216,12 @@ export const ClientProvider: FC<Props> = ({ children }) => {
           isPasswordlessUser,
           userName: client?.getUserIdLocalpart(),
           error: undefined,
+          disconnected: isDisconnected(
+            client?.getSyncState,
+            client?.getSyncStateData
+          ),
         });
+        clientWithListener?.on(ClientEvent.Sync, onSync);
       })
       .catch((err) => {
         logger.error(err);
@@ -204,9 +232,13 @@ export const ClientProvider: FC<Props> = ({ children }) => {
           isPasswordlessUser: false,
           userName: null,
           error: undefined,
+          disconnected: false,
         });
       })
       .finally(() => (initializing.current = false));
+    return () => {
+      clientWithListener?.removeListener(ClientEvent.Sync, onSync);
+    };
   }, []);
 
   const changePassword = useCallback(
@@ -235,6 +267,7 @@ export const ClientProvider: FC<Props> = ({ children }) => {
         isPasswordlessUser: false,
         userName: client.getUserIdLocalpart(),
         error: undefined,
+        disconnected: false,
       });
     },
     [client]
@@ -256,6 +289,10 @@ export const ClientProvider: FC<Props> = ({ children }) => {
           isPasswordlessUser: session.passwordlessUser,
           userName: newClient.getUserIdLocalpart(),
           error: undefined,
+          disconnected: isDisconnected(
+            newClient.getSyncState(),
+            newClient.getSyncStateData()
+          ),
         });
       } else {
         clearSession();
@@ -267,6 +304,7 @@ export const ClientProvider: FC<Props> = ({ children }) => {
           isPasswordlessUser: false,
           userName: null,
           error: undefined,
+          disconnected: false,
         });
       }
     },
@@ -284,6 +322,7 @@ export const ClientProvider: FC<Props> = ({ children }) => {
       isPasswordlessUser: true,
       userName: "",
       error: undefined,
+      disconnected: false,
     });
     history.push("/");
     PosthogAnalytics.instance.setRegistrationType(RegistrationType.Guest);
@@ -326,6 +365,7 @@ export const ClientProvider: FC<Props> = ({ children }) => {
       userName,
       setClient,
       error: undefined,
+      disconnected,
     }),
     [
       loading,
@@ -336,6 +376,7 @@ export const ClientProvider: FC<Props> = ({ children }) => {
       logout,
       userName,
       setClient,
+      disconnected,
     ]
   );
 

src/DisconnectedBanner.module.css

@@ -0,0 +1,27 @@
+/*
+Copyright 2023 New Vector Ltd
+
+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.
+*/
+
+.banner {
+  position: absolute;
+  padding: 29px;
+  background-color: var(--quaternary-content);
+  vertical-align: middle;
+  font-size: var(--font-size-body);
+  text-align: center;
+  z-index: 1;
+  top: 76px;
+  width: calc(100% - 58px);
+}

src/DisconnectedBanner.tsx

@@ -0,0 +1,47 @@
+/*
+Copyright 2023 New Vector Ltd
+
+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 classNames from "classnames";
+import React, { HTMLAttributes, ReactNode } from "react";
+import { useTranslation } from "react-i18next";
+
+import styles from "./DisconnectedBanner.module.css";
+import { useClient } from "./ClientContext";
+
+interface DisconnectedBannerProps extends HTMLAttributes<HTMLElement> {
+  children?: ReactNode;
+  className?: string;
+}
+
+export function DisconnectedBanner({
+  children,
+  className,
+  ...rest
+}: DisconnectedBannerProps) {
+  const { t } = useTranslation();
+  const { disconnected } = useClient();
+
+  return (
+    <>
+      {disconnected && (
+        <div className={classNames(styles.banner, className)} {...rest}>
+          {children}
+          {t("Connectivity to the server has been lost.")}
+        </div>
+      )}
+    </>
+  );
+}

src/initializer.tsx

@@ -45,6 +45,12 @@ class DependencyLoadStates {
 
 export class Initializer {
   private static internalInstance: Initializer;
+  private isInitialized = false;
+
+  public static isInitialized(): boolean {
+    return Initializer.internalInstance?.isInitialized;
+  }
+
   public static initBeforeReact() {
     // this maybe also needs to return a promise in the future,
     // if we have to do async inits before showing the loading screen
@@ -223,6 +229,7 @@ export class Initializer {
     if (this.loadStates.allDepsAreLoaded()) {
       // resolve if there is no dependency that is not loaded
       resolve();
+      this.isInitialized = true;
     }
   }
   private initPromise: Promise<void> | null;

src/matrix-utils.ts

@@ -61,11 +61,11 @@ function waitForSync(client: MatrixClient) {
       data: ISyncStateData
     ) => {
       if (state === "PREPARED") {
+        client.removeListener(ClientEvent.Sync, onSync);
         resolve();
-        client.removeListener(ClientEvent.Sync, onSync);
       } else if (state === "ERROR") {
-        reject(data?.error);
         client.removeListener(ClientEvent.Sync, onSync);
+        reject(data?.error);
       }
     };
     client.on(ClientEvent.Sync, onSync);