Error messages

lib/services/scaffold_messenger.dart

@@ -0,0 +1,15 @@
+import 'package:flutter/material.dart';
+
+class Messenger {
+  static void showError(BuildContext context, String error) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        backgroundColor: Theme.of(context).colorScheme.error,
+        content: Text(
+          error,
+          style: TextStyle(color: Theme.of(context).colorScheme.onError),
+        ),
+      ),
+    );
+  }
+}