working save and load functionality with custom datastructures

frontend/lib/layout.dart

@@ -12,7 +12,7 @@ import 'package:fast_network_navigation/pages/profile.dart';
 // A side drawer is used to switch between pages
 class BasePage extends StatefulWidget {
   final String mainScreen;
-  final Trip? trip;
+  final Future<Trip>? trip;
   
   const BasePage({
     super.key,
@@ -30,11 +30,10 @@ class _BasePageState extends State<BasePage> {
   Widget build(BuildContext context) {
     Widget currentView = const Text("loading...");
     Future<List<Trip>> trips = loadTrips();
-    Future<Trip> firstTrip = getFirstTrip(trips);
-    // Future<Trip> trip = Future(trips[0]);
+    
     
     if (widget.mainScreen == "map") {
-      currentView = NavigationOverview(trip: firstTrip);
+      currentView = NavigationOverview(trip: widget.trip ?? getFirstTrip(trips));
     } else if (widget.mainScreen == "tutorial") {
       currentView = TutorialPage();
     } else if (widget.mainScreen == "profile") {
@@ -88,12 +87,8 @@ class _BasePageState extends State<BasePage> {
               child: TripsOverview(trips: trips),
             ),
             ElevatedButton(
-              onPressed: () {
-                Navigator.of(context).push(
-                  MaterialPageRoute(
-                    builder: (context) => const NewTripPage()
-                  )
-                );
+              onPressed: () async {
+                removeAllTripsFromPrefs();
               },
               child: const Text('Clear trips'),
             ),