outsourced all methods and dialogs as far as possible (I think)

lib/screens/helper/snack_bar_helper.dart

@@ -0,0 +1,8 @@
+import 'package:flutter/material.dart';
+
+class SnackBarHelper {
+  static void showSnackBarMessage(BuildContext context, String message) {
+    ScaffoldMessenger.of(context)
+        .showSnackBar(SnackBar(content: Text(message)));
+  }
+}