Tracking now works via timed interval

lib/screens/excursion/widgets/tracking.dart

@@ -22,7 +22,7 @@ class Tracking extends StatefulWidget {
 
 class _TrackingState extends State<Tracking> {
   final TrackingService _trackingService = TrackingService();
-  LocationMarkerPosition? locationMarkerPosition;
+  Position? currentPosition;
   MapController mapController = MapController();
   StreamSubscription? _positionSubscription;
   StreamSubscription? _statsSubscription;
@@ -48,11 +48,7 @@ class _TrackingState extends State<Tracking> {
       }
     }
 
-    locationMarkerPosition = LocationMarkerPosition(
+    currentPosition = widget.startPosition;
-      latitude: widget.startPosition.latitude,
-      longitude: widget.startPosition.longitude,
-      accuracy: widget.startPosition.accuracy,
-    );
 
     // Initialisiere die Statistiken sofort
     setState(() {
@@ -62,11 +58,7 @@ class _TrackingState extends State<Tracking> {
 
     _positionSubscription = _trackingService.positionStream$.listen((position) {
       setState(() {
-        locationMarkerPosition = LocationMarkerPosition(
+        currentPosition = position;
-          latitude: position.latitude,
-          longitude: position.longitude,
-          accuracy: position.accuracy,
-        );
       });
     });
 
@@ -163,11 +155,7 @@ class _TrackingState extends State<Tracking> {
                 if (_trackingService.isTracking) {
                   _trackingService.pauseTracking();
                 } else {
-                  if (_trackingService.positionStream == null) {
                   _trackingService.startTracking(context);
-                  } else {
-                    _trackingService.resumeTracking();
-                  }
                 }
               });
             },
@@ -181,8 +169,8 @@ class _TrackingState extends State<Tracking> {
         onPressed: () {
           mapController.move(
             LatLng(
-              locationMarkerPosition!.latitude,
+              currentPosition!.latitude,
-              locationMarkerPosition!.longitude,
+              currentPosition!.longitude,
             ),
             16,
           );
@@ -218,6 +206,31 @@ class _TrackingState extends State<Tracking> {
                 ),
               ],
             ),
+          if (currentPosition != null)
+            CircleLayer(
+              circles: [
+                CircleMarker(
+                  point: LatLng(
+                    currentPosition!.latitude,
+                    currentPosition!.longitude,
+                  ),
+                  radius: currentPosition!.accuracy,
+                  color: Colors.blue.withOpacity(0.2),
+                  borderColor: Colors.blue,
+                  borderStrokeWidth: 2,
+                ),
+                CircleMarker(
+                  point: LatLng(
+                    currentPosition!.latitude,
+                    currentPosition!.longitude,
+                  ),
+                  radius: 5,
+                  color: Colors.blue,
+                  borderColor: Colors.white,
+                  borderStrokeWidth: 2,
+                ),
+              ],
+            ),
           CurrentLocationLayer(),
         ],
       ),

lib/screens/settings.dart

@@ -10,36 +10,75 @@ class Settings extends StatefulWidget {
 }
 
 class _SettingsState extends State<Settings> {
+  int _trackingInterval = 60;
 
+  @override
+  void initState() {
+    super.initState();
+    _loadSettings();
+  }
+
+  Future<void> _loadSettings() async {
+    SharedPreferences prefs = await SharedPreferences.getInstance();
+    setState(() {
+      _trackingInterval = prefs.getInt('trackingInterval') ?? 60;
+    });
+  }
+
+  Future<void> _saveTrackingInterval(int value) async {
+    SharedPreferences prefs = await SharedPreferences.getInstance();
+    await prefs.setInt('trackingInterval', value);
+    setState(() {
+      _trackingInterval = value;
+    });
+  }
 
   Future<String> _getSaveDir() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
-
     final String saveDir = prefs.getString('saveDir') ?? "";
-
     return saveDir;
   }
 
-
-
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(title: Text(AppLocalizations.of(context)!.settings),),
-      body: Center(
+      body: Padding(
+        padding: const EdgeInsets.all(16.0),
         child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
           children: [
             Text(AppLocalizations.of(context)!.filelocation, style: const TextStyle(fontSize: 20),),
-            FutureBuilder(future: _getSaveDir(), builder: (context, snapshot) {
+            FutureBuilder(
+              future: _getSaveDir(), 
+              builder: (context, snapshot) {
                 if (snapshot.connectionState == ConnectionState.done) {
                   return Text(snapshot.data ?? "");
                 } else {
                   return const CircularProgressIndicator();
                 }
-            }),
+              }
-            ElevatedButton(onPressed: () {
+            ),
-              
+            ElevatedButton(
-            }, child: Text(AppLocalizations.of(context)!.open))
+              onPressed: () {}, 
+              child: Text(AppLocalizations.of(context)!.open)
+            ),
+            const SizedBox(height: 24),
+            const Text(
+              'Tracking Interval (Sekunden)',
+              style: TextStyle(fontSize: 20),
+            ),
+            Slider(
+              value: _trackingInterval.toDouble(),
+              min: 10,
+              max: 300,
+              divisions: 29,
+              label: _trackingInterval.toString(),
+              onChanged: (double value) {
+                _saveTrackingInterval(value.round());
+              },
+            ),
+            Text('Aktuelles Intervall: $_trackingInterval Sekunden'),
           ],
         ),
       ),

lib/services/tracking_service.dart

@@ -6,6 +6,7 @@ import 'package:fforte/services/notification_service.dart';
 import 'package:flutter/material.dart';
 import 'package:geolocator/geolocator.dart';
 import 'package:latlong2/latlong.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class TrackingService {
   static final TrackingService _instance = TrackingService._internal();
@@ -14,8 +15,9 @@ class TrackingService {
 
   List<LatLng> pathList = [];
   List<double> accuracyList = [];
-  StreamSubscription<Position>? positionStream;
+  Timer? _positionTimer;
   bool isTracking = false;
+  BuildContext? _lastContext;
   final _positionController = StreamController<Position>.broadcast();
   final _statsController = StreamController<TrackingStats>.broadcast();
 
@@ -44,34 +46,49 @@ class TrackingService {
   Future<void> startTracking(BuildContext context) async {
     if (isTracking) return;
 
+    _lastContext = context;
     await NotificationService().initNotification();
     NotificationService().showNotification(
       title: AppLocalizations.of(context)!.trackingRunningInBackground,
     );
 
-    positionStream = Geolocator.getPositionStream(
+    // Get tracking interval from settings
-      locationSettings: AndroidSettings(
+    final prefs = await SharedPreferences.getInstance();
-        accuracy: LocationAccuracy.high,
+    final intervalSeconds = prefs.getInt('trackingInterval') ?? 60;
-        distanceFilter: 0,
+
-        foregroundNotificationConfig: ForegroundNotificationConfig(
+    // Create a timer that triggers position updates
-          notificationTitle: AppLocalizations.of(context)!.trackingRunningInBackground,
+    _positionTimer = Timer.periodic(Duration(seconds: intervalSeconds), (_) async {
-          notificationText: "",
+      try {
-        ),
+        final Position position = await Geolocator.getCurrentPosition(
-      ),
+          desiredAccuracy: LocationAccuracy.high,
-    ).listen((Position? position) {
+        );
-      if (position != null) {
+        
         pathList.add(LatLng(position.latitude, position.longitude));
         accuracyList.add(position.accuracy);
         currentAccuracy = position.accuracy;
         _positionController.add(position);
         _updateStats();
+      } catch (e) {
+        NotificationService().deleteNotification();
+        NotificationService().showNotification(title: "ERROR: $e");
       }
     });
 
-    positionStream!.onError((e) {
+    // Get initial position immediately
+    try {
+      final Position position = await Geolocator.getCurrentPosition(
+        desiredAccuracy: LocationAccuracy.high,
+      );
+      
+      pathList.add(LatLng(position.latitude, position.longitude));
+      accuracyList.add(position.accuracy);
+      currentAccuracy = position.accuracy;
+      _positionController.add(position);
+      _updateStats();
+    } catch (e) {
       NotificationService().deleteNotification();
       NotificationService().showNotification(title: "ERROR: $e");
-    });
+    }
 
     isTracking = true;
   }
@@ -131,21 +148,24 @@ class TrackingService {
   }
 
   void pauseTracking() {
-    positionStream?.pause();
+    _positionTimer?.cancel();
     isTracking = false;
   }
 
   void resumeTracking() {
-    positionStream?.resume();
+    if (!isTracking && _lastContext != null) {
+      startTracking(_lastContext!);
+    }
     isTracking = true;
   }
 
   void stopTracking() {
-    positionStream?.cancel();
+    _positionTimer?.cancel();
     NotificationService().deleteNotification();
     isTracking = false;
     accuracyList.clear();
     currentAccuracy = null;
+    _lastContext = null;
   }
 
   void clearPath() {