fix: #8 save lat lng on map move to restore view

lib/src/map/map_view.dart

@@ -57,6 +57,8 @@ class MapViewState extends State<MapView> with TickerProviderStateMixin {
   late AlignOnUpdate _alignPositionOnUpdate;
   late final StreamController<double?> _alignPositionStreamController;
   double restoredZoomed = 0; // To restore zoom level when unlocking position
+  // Widget internal utils
+  Timer? _debounce; // o debounce the saving of initial lat/lng on map move
   // InitState main purpose is to async load spots/shops/bars
   @override
   void initState() {
@@ -321,9 +323,9 @@ class MapViewState extends State<MapView> with TickerProviderStateMixin {
       body: FlutterMap(
         mapController: _mapController,
         options: MapOptions(
-          initialCenter: const LatLng(
-            48.8605277263,
-            2.34402407374,
+          initialCenter: LatLng(
+            widget.settingsController.initLat,
+            widget.settingsController.initLng,
           ),
           initialZoom: 11.0,
           interactionOptions: const InteractionOptions(
@@ -346,6 +348,19 @@ class MapViewState extends State<MapView> with TickerProviderStateMixin {
             if (hasGesture && _alignPositionOnUpdate != AlignOnUpdate.never) {
               setState(() => _alignPositionOnUpdate = AlignOnUpdate.never);
             }
+            // Update center map to initial lat/lng
+            if (_debounce?.isActive ?? false) _debounce?.cancel();
+            _debounce = Timer(
+              const Duration(
+                milliseconds: 500,
+              ),
+              () {
+                widget.settingsController.updateInitialPosition(
+                  position.center.latitude,
+                  position.center.longitude,
+                );
+              },
+            );
           },
           // Map clicked callback, add marker only if logged in
           onTap: (widget.settingsController.isLoggedIn == true)

lib/src/settings/settings_controller.dart

@@ -28,6 +28,9 @@ class SettingsController with ChangeNotifier {
   late String ppPath;
   late bool isUserActive;
   late bool isUserStaff;
+  // Map saved settings
+  double initLat = 48.8605277263;
+  double initLng = 2.34402407374;
   // Load settings from storage. Required before loading app
   Future<void> loadSettings() async {
     _themeMode = await _settingsService.themeMode();
@@ -44,6 +47,8 @@ class SettingsController with ChangeNotifier {
     } else {
       isLoggedIn = false;
     }
+    initLat = await _settingsService.initialLat();
+    initLng = await _settingsService.initialLng();
     // Finally notify listener that settings are loaded, app can be started
     notifyListeners();
   }
@@ -80,6 +85,18 @@ class SettingsController with ChangeNotifier {
     await _settingsService.updateShowWelcomeScreen(showWelcomeScreen);
     notifyListeners();
   }
+  // Update initial lat/lng position
+  Future<void> updateInitialPosition(
+    double lat,
+    double lng,
+  ) async {
+    if (lat < -90 || lat > 90) return;
+    if (lng < -180 || lng > 180) return;
+    initLat = lat;
+    initLng = lng;
+    await _settingsService.updateInitialPosition(lat, lng);
+    notifyListeners();
+  }
 
   /* Auth related methods */
 

lib/src/settings/settings_service.dart

@@ -87,6 +87,34 @@ class SettingsService {
       }
     }
   }
+  // Returns initial stored lat position
+  Future<double> initialLat() async {
+    final SharedPreferences appPreferences = await SharedPreferences.getInstance();
+    double? value = appPreferences.getDouble('bc-initial-pos-lat');
+    if (value == null) {
+      await appPreferences.setDouble(
+        'bc-initial-pos-lat',
+        48.8605277263,
+      );
+      return 48.8605277263;
+    } else {
+      return value;
+    }
+  }
+  // Returns initial stored lng position
+  Future<double> initialLng() async {
+    final SharedPreferences appPreferences = await SharedPreferences.getInstance();
+    double? value = appPreferences.getDouble('bc-initial-pos-lng');
+    if (value == null) {
+      await appPreferences.setDouble(
+        'bc-initial-pos-lng',
+        2.34402407374,
+      );
+      return 2.34402407374;
+    } else {
+      return value;
+    }
+  }
   // Persists the user's preferred ThemeMode to device storage
   Future<void> updateThemeMode(
     ThemeMode theme,
@@ -146,6 +174,21 @@ class SettingsService {
       );      
     }
   }
+  // Update the saved initial position to restore map to latest view position on map
+  Future<void> updateInitialPosition(
+    double lat,
+    double lng,
+  ) async {
+    final SharedPreferences appPreferences = await SharedPreferences.getInstance();
+    await appPreferences.setDouble(
+      'bc-initial-pos-lat',
+      lat,
+    );
+    await appPreferences.setDouble(
+      'bc-initial-pos-lng',
+      lng,
+    );
+  }
   // Persists the user's JWT token in device secure storage
   Future<void> updateAuthToken(
     String expiry,