handle connectivity fails (like nm being unavail on build server) more gracefully

lib/main.dart

@@ -65,7 +65,7 @@ class FlwtchState extends State<Flwtch> with WindowListener {
   final MethodChannel notificationClickChannel = MethodChannel('im.cwtch.flwtch/notificationClickHandler');
   final MethodChannel shutdownMethodChannel = MethodChannel('im.cwtch.flwtch/shutdownClickHandler');
   final MethodChannel shutdownLinuxMethodChannel = MethodChannel('im.cwtch.linux.shutdown');
-  late StreamSubscription connectivityStream;
+  late StreamSubscription? connectivityStream;
   ConnectivityState connectivityState = ConnectivityState.assumed_online;
 
   final GlobalKey<NavigatorState> navKey = GlobalKey<NavigatorState>();
@@ -95,35 +95,74 @@ class FlwtchState extends State<Flwtch> with WindowListener {
     shutdownLinuxMethodChannel.setMethodCallHandler(shutdownDirect);
     print("initState: creating cwtchnotifier, ffi");
     if (Platform.isAndroid) {
-      var cwtchNotifier = new CwtchNotifier(profs, globalSettings, globalErrorHandler, globalTorStatus, NullNotificationsManager(), globalAppState, globalServersList, this);
+      var cwtchNotifier = new CwtchNotifier(
+          profs,
+          globalSettings,
+          globalErrorHandler,
+          globalTorStatus,
+          NullNotificationsManager(),
+          globalAppState,
+          globalServersList,
+          this);
       cwtch = CwtchGomobile(cwtchNotifier);
     } else if (Platform.isLinux) {
       var cwtchNotifier =
-          new CwtchNotifier(profs, globalSettings, globalErrorHandler, globalTorStatus, newDesktopNotificationsManager(_notificationSelectConvo), globalAppState, globalServersList, this);
+      new CwtchNotifier(
+          profs,
+          globalSettings,
+          globalErrorHandler,
+          globalTorStatus,
+          newDesktopNotificationsManager(_notificationSelectConvo),
+          globalAppState,
+          globalServersList,
+          this);
       cwtch = CwtchFfi(cwtchNotifier);
     } else {
       var cwtchNotifier =
-          new CwtchNotifier(profs, globalSettings, globalErrorHandler, globalTorStatus, newDesktopNotificationsManager(_notificationSelectConvo), globalAppState, globalServersList, this);
+      new CwtchNotifier(
+          profs,
+          globalSettings,
+          globalErrorHandler,
+          globalTorStatus,
+          newDesktopNotificationsManager(_notificationSelectConvo),
+          globalAppState,
+          globalServersList,
+          this);
       cwtch = CwtchFfi(cwtchNotifier);
     }
-    connectivityStream = Connectivity().onConnectivityChanged.listen((ConnectivityResult result) {
+    startConnectivityListener();
-      // Got a new connectivity status!
-      if (result == ConnectivityResult.none) {
-        connectivityState = ConnectivityState.confirmed_offline;
-      } else {
-        // were we offline?
-        if (connectivityState == ConnectivityState.confirmed_offline) {
-          EnvironmentConfig.debugLog("Network appears to have come back online, restarting Tor");
-          cwtch.ResetTor();
-        }
-        connectivityState = ConnectivityState.confirmed_online;
-      }
-    });
     print("initState: invoking cwtch.Start()");
     cwtch.Start();
     print("initState: done!");
   }
 
+  // connectivity listening is an optional enhancement feature that tries to listen for OS events about the network
+  // and if it detects coming back online, restarts the ACN/tor
+  // gracefully fails and NOPs, as it's not a required functionality
+  startConnectivityListener() async  {
+    try {
+      connectivityStream = await Connectivity().onConnectivityChanged.listen((ConnectivityResult result) {
+        // Got a new connectivity status!
+        if (result == ConnectivityResult.none) {
+          connectivityState = ConnectivityState.confirmed_offline;
+        } else {
+          // were we offline?
+          if (connectivityState == ConnectivityState.confirmed_offline) {
+            EnvironmentConfig.debugLog("Network appears to have come back online, restarting Tor");
+            cwtch.ResetTor();
+          }
+          connectivityState = ConnectivityState.confirmed_online;
+        }
+      }, onError: (Object error) {
+        print("Error listening to connectivity for network state: {$error}");
+        return null;
+      }, cancelOnError: true);
+    } catch (e) {
+      print("Warning: Unable to open connectivity for listening to network state: {$e}");
+      connectivityStream = null;
+    }
+  }
+
   ChangeNotifierProvider<TorStatus> getTorStatusProvider() => ChangeNotifierProvider.value(value: globalTorStatus);
   ChangeNotifierProvider<ErrorHandler> getErrorHandlerProvider() => ChangeNotifierProvider.value(value: globalErrorHandler);
   ChangeNotifierProvider<Settings> getSettingsProvider() => ChangeNotifierProvider.value(value: globalSettings);
@@ -295,7 +334,7 @@ class FlwtchState extends State<Flwtch> with WindowListener {
     cwtch.Shutdown();
     windowManager.removeListener(this);
     cwtch.dispose();
-    connectivityStream.cancel();
+    connectivityStream?.cancel();
     super.dispose();
   }
 }

lib/third_party/nm/src/network_manager_client.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:io';
 
 import 'package:dbus/dbus.dart';
 
@@ -314,6 +315,17 @@ class NetworkManagerClient {
       return;
     }
 
+    // Big old grody Hack
+    // DBus/nm doesnt seem to offer a way to deter ine if dbus is available on system
+    // worse the first connections get triggered in dbus_client onListen an isn't a catahable exception so crashes the app
+    // this is a hacky way to force an exception on thread if dbus isn't available and bail with out crashing
+    try {
+      await _root.client.getNameOwner(_root.name);
+    } on SocketException catch (e) {
+      print("nm dbus connect/emit test threw exception, dbus likely unavailable on system, aborting connect: $e");
+      return;
+    }
+
     // Subscribe to changes
     _objectManagerSubscription = _root.signals.listen((signal) {
       if (signal is DBusObjectManagerInterfacesAddedSignal) {

pubspec.yaml

@@ -32,6 +32,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.0
+  # Todo: upgrade to 2.x, allow other package upgrades (dbus)
   ffi: ^1.2.1
   path_provider: ^2.0.0
   crypto: ^3.0.2