exception if launchUrl fails

lib/main.dart

@@ -60,7 +60,7 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'LeineLab e.V. Key App',
       theme: ThemeData(
         colorScheme: ColorScheme.fromSeed(seedColor: Colors.yellow),
       ),
@@ -81,12 +81,23 @@ class MyHomePage extends StatefulWidget {
 class _MyHomePageState extends State<MyHomePage> {
   int navIndex = 0;
   OpenSSHEd25519KeyPair? keyPair;
-  String _output = '';
+  String? _output;
+  SSHClient? client;
   String key = '';
 
   Future<void> doSSH(String user) async {
     SSHSocket? socket;
 
+    if (client != null) {
+      // If we already have a client, close it
+      client!.close();
+      client = null;
+    }
+
+    setState(() {
+      _output = null;
+    });
+
     try {
       socket = await SSHSocket.connect(
         '192.168.0.15',
@@ -94,17 +105,48 @@ class _MyHomePageState extends State<MyHomePage> {
         timeout: const Duration(seconds: 0, milliseconds: 500),
       );
 
-      final client = SSHClient(
+      client = SSHClient(
         socket,
         username: user,
         identities: List.of(keyPair != null ? [keyPair!] : []),
       );
 
-      final uptime = await client.run('uptime');
       setState(() {
-        _output = utf8.decode(uptime);
+        _output = 'Connecting to SSH server...\n\n';
+      });
+
+      if (client == null) {
+        return;
+      }
+
+      final shell = await client!.shell();
+
+      shell.stdout.listen((data) {
+        setState(() {
+          if (_output == null) {
+            return;
+          }
+          _output = _output! + utf8.decode(data);
+        });
+      });
+
+      if (client == null) {
+        return;
+      }
+
+      await shell.done;
+
+      if (client == null) {
+        return;
+      }
+      client!.close();
+      setState(() {
+        _output = null;
       });
     } on SSHAuthError catch (_) {
+      setState(() {
+        _output = null;
+      });
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(
           content: Text(
@@ -115,6 +157,9 @@ class _MyHomePageState extends State<MyHomePage> {
       );
       return;
     } on SocketException catch (_) {
+      setState(() {
+        _output = null;
+      });
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(
           content: Text(
@@ -382,11 +427,7 @@ class _MyHomePageState extends State<MyHomePage> {
       ),
     );
 
-    if (authentikApiState.isClosed()) {
-      return mainPage;
-    }
-
-    Widget title;
+    Widget? title;
     var children = <Widget>[];
     var actions = [
       TextButton(onPressed: authentikApiState.exit, child: Text("Cancel")),
@@ -394,7 +435,7 @@ class _MyHomePageState extends State<MyHomePage> {
 
     switch (authentikApiState.status) {
       case AuthentikUserSettingsChangeDialogStatus.closed:
-        return mainPage;
+        break;
       case AuthentikUserSettingsChangeDialogStatus.waitingForOAuth:
         title = Text("Waiting for OAuth");
         children = [Text("Please complete the OAuth flow in your browser.")];
@@ -429,6 +470,31 @@ class _MyHomePageState extends State<MyHomePage> {
         children = [Text("Saving...")];
     }
 
+    if (_output != null) {
+      title = Text("SSH Output");
+      children.add(Text(_output!, style: TextStyle(fontSize: 12)));
+      // TODO: fix action.
+      actions = [
+        TextButton(
+          onPressed: () {
+            setState(() {
+              _output = null;
+              if (client != null) {
+                client!.close();
+                client = null;
+              }
+            });
+          },
+          child: Text("Cancel"),
+        ),
+      ];
+    }
+
+    if (title == null) {
+      // If we have no title, just return the main page
+      return mainPage;
+    }
+
     final dialog = AlertDialog(
       title: title,
       content: SingleChildScrollView(child: Column(children: children)),
@@ -498,7 +564,12 @@ class AuthentikUserSettingsChangeDialogState extends ChangeNotifier {
 
     server = await HttpServer.bind("127.0.0.1", 30165);
 
-    await launchUrl(authorizationUrl, mode: LaunchMode.externalApplication);
+    if (!await launchUrl(
+      authorizationUrl,
+      mode: LaunchMode.externalApplication,
+    )) {
+      throw Exception("Could not launch the authorization URL.");
+    }
 
     if (server == null) {
       // exit() might have been called before we arrived here.