location picker and ui fixes

frontend/lib/structs/trip.dart

@@ -3,6 +3,7 @@
 
 import 'dart:collection';
 import 'dart:convert';
+import 'dart:developer';
 
 import 'package:anyway/structs/landmark.dart';
 import 'package:flutter/foundation.dart';
@@ -75,8 +76,11 @@ class Trip with ChangeNotifier {
     String? content = prefs.getString('trip_$uuid');
     Map<String, dynamic> json = jsonDecode(content!);
     Trip trip = Trip.fromJson(json);
-    String? firstUUID = json['entry_uuid'];
-    readLandmarks(trip.landmarks, prefs, firstUUID);
+    String? firstUUID = json['first_landmark_uuid'];
+    log('Loading trip $uuid with first landmark $firstUUID');
+    LinkedList<Landmark> landmarks = readLandmarks(prefs, firstUUID);
+    trip.landmarks = landmarks;
+    // notifyListeners();
     return trip;
   }
 
@@ -90,6 +94,7 @@ class Trip with ChangeNotifier {
 
   void toPrefs(SharedPreferences prefs){
     Map<String, dynamic> json = toJson();
+    log('Saving trip $uuid : $json');
     prefs.setString('trip_$uuid', jsonEncode(json));
     for (Landmark landmark in landmarks) {
       landmarkToPrefs(prefs, landmark, landmark.next);
@@ -99,12 +104,14 @@ class Trip with ChangeNotifier {
 
 
 // Helper
-readLandmarks(LinkedList<Landmark> landmarks, SharedPreferences prefs, String? firstUUID) {
+LinkedList<Landmark> readLandmarks(SharedPreferences prefs, String? firstUUID) {
+  LinkedList<Landmark> landmarks = LinkedList<Landmark>();
   while (firstUUID != null) {
     var (head, nextUUID) = getLandmarkFromPrefs(prefs, firstUUID);
     landmarks.add(head);
     firstUUID = nextUUID;
   }
+  return landmarks;
 }