Navigation start+end too close warning

README.md

@@ -107,7 +107,6 @@ cp lib/keys.dart.example lib/keys.dart
   - Manual cleanup (cognitive load for users)
   - Delete the old one (also wrong answer unless user chooses intentionally)
   - Give multiple of these options??
-- Nav start+end too close together error (warning + disable submit button?)
 - Persistent cache for MY submissions: assume submissions worked, cache,clean up when we see that node appear in overpass/OSM results or when older than 24h
 - Dropdown on "refine tags" page to select acceptable options for camera:mount= (is this a boolean property of a profile?)
 - Option to pull in profiles from NSI (man_made=surveillance only?)

assets/changelog.json

@@ -2,7 +2,9 @@
   "1.5.4": {
     "content": [
       "• FIXED: Download area max zoom level is now limited to the currently selected tile provider's maximum zoom level (e.g., OpenTopoMap limited to Z18, Bing Maps to Z20)",
-      "• IMPROVED: Download area dialog properly respects tile provider capabilities and prevents downloading tiles beyond what the provider supports"
+      "• IMPROVED: Download area dialog properly respects tile provider capabilities and prevents downloading tiles beyond what the provider supports",
+      "• NEW: Navigation route planning now prevents selecting start and end locations that are too close together (configurable minimum distance)",
+      "• IMPROVED: 'Select Location' button is disabled and shows warning message when route points are closer than 100 meters apart"
     ]
   },
   "1.5.3": {

lib/app_state.dart

@@ -112,6 +112,7 @@ class AppState extends ChangeNotifier {
   double? get routeDistance => _navigationState.routeDistance;
   bool get settingRouteStart => _navigationState.settingRouteStart;
   bool get isSettingSecondPoint => _navigationState.isSettingSecondPoint;
+  bool get areRoutePointsTooClose => _navigationState.areRoutePointsTooClose;
   bool get isCalculating => _navigationState.isCalculating;
   bool get showingOverview => _navigationState.showingOverview;
   String? get routingError => _navigationState.routingError;

lib/dev_config.dart

@@ -124,6 +124,9 @@ const Duration kProximityAlertCooldown = Duration(minutes: 10); // Cooldown betw
 // Node proximity warning configuration (for new/edited nodes that are too close to existing ones)
 const double kNodeProximityWarningDistance = 15.0; // meters - distance threshold to show warning
 
+// Navigation route planning configuration
+const double kNavigationMinRouteDistance = 100.0; // meters - minimum distance between start and end points
+
 // Map interaction configuration
 const double kNodeDoubleTapZoomDelta = 1.0; // How much to zoom in when double-tapping nodes (was 1.0)
 const double kScrollWheelVelocity = 0.01; // Mouse scroll wheel zoom speed (default 0.005)

lib/localizations/de.json

@@ -460,6 +460,7 @@
     "endSelect": "Ende (auswählen)",
     "distance": "Entfernung: {} km",
     "routeActive": "Route aktiv",
+    "locationsTooClose": "Start- und Endpositionen sind zu nah beieinander",
     "navigationSettings": "Navigation",
     "navigationSettingsSubtitle": "Routenplanung und Vermeidungseinstellungen",
     "avoidanceDistance": "Vermeidungsabstand",

lib/localizations/en.json

@@ -460,6 +460,7 @@
     "endSelect": "End (select)",
     "distance": "Distance: {} km",
     "routeActive": "Route active",
+    "locationsTooClose": "Start and end locations are too close together",
     "navigationSettings": "Navigation",
     "navigationSettingsSubtitle": "Route planning and avoidance settings",
     "avoidanceDistance": "Avoidance Distance",

lib/localizations/es.json

@@ -460,6 +460,7 @@
     "endSelect": "Fin (seleccionar)",
     "distance": "Distancia: {} km",
     "routeActive": "Ruta activa",
+    "locationsTooClose": "Las ubicaciones de inicio y fin están demasiado cerca",
     "navigationSettings": "Navegación",
     "navigationSettingsSubtitle": "Configuración de planificación de rutas y evitación",
     "avoidanceDistance": "Distancia de evitación",

lib/localizations/fr.json

@@ -460,6 +460,7 @@
     "endSelect": "Fin (sélectionner)",
     "distance": "Distance: {} km",
     "routeActive": "Itinéraire actif",
+    "locationsTooClose": "Les emplacements de départ et d'arrivée sont trop proches",
     "navigationSettings": "Navigation",
     "navigationSettingsSubtitle": "Paramètres de planification d'itinéraire et d'évitement",
     "avoidanceDistance": "Distance d'évitement",

lib/state/navigation_state.dart

@@ -4,6 +4,7 @@ import 'package:latlong2/latlong.dart';
 import '../models/search_result.dart';
 import '../services/search_service.dart';
 import '../services/routing_service.dart';
+import '../dev_config.dart';
 
 /// Simplified navigation modes - brutalist approach
 enum AppNavigationMode {
@@ -75,6 +76,17 @@ class NavigationState extends ChangeNotifier {
   bool get showSearchButton => _mode == AppNavigationMode.normal;
   bool get showRouteButton => _mode == AppNavigationMode.routeActive;
   
+  /// Check if the start and end locations are too close together
+  bool get areRoutePointsTooClose {
+    if (!_isSettingSecondPoint || _provisionalPinLocation == null) return false;
+    
+    final firstPoint = _nextPointIsStart ? _routeEnd : _routeStart;
+    if (firstPoint == null) return false;
+    
+    final distance = const Distance().as(LengthUnit.Meter, firstPoint, _provisionalPinLocation!);
+    return distance < kNavigationMinRouteDistance;
+  }
+  
   /// BRUTALIST: Single entry point to search mode
   void enterSearchMode(LatLng mapCenter) {
     debugPrint('[NavigationState] enterSearchMode - current mode: $_mode');

lib/widgets/navigation_sheet.dart

@@ -159,10 +159,38 @@ class NavigationSheet extends StatelessWidget {
                 ),
                 const SizedBox(height: 16),
                 
+                // Show warning message if locations are too close
+                if (appState.areRoutePointsTooClose) ...[
+                  Container(
+                    padding: const EdgeInsets.all(12),
+                    decoration: BoxDecoration(
+                      color: Colors.orange.withOpacity(0.1),
+                      borderRadius: BorderRadius.circular(8),
+                      border: Border.all(color: Colors.orange.withOpacity(0.3)),
+                    ),
+                    child: Row(
+                      children: [
+                        Icon(Icons.warning, color: Colors.orange[700], size: 20),
+                        const SizedBox(width: 8),
+                        Expanded(
+                          child: Text(
+                            LocalizationService.instance.t('navigation.locationsTooClose'),
+                            style: TextStyle(
+                              fontSize: 14,
+                              color: Colors.orange[700],
+                            ),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  const SizedBox(height: 16),
+                ],
+                
                 ElevatedButton.icon(
                   icon: const Icon(Icons.check),
                   label: Text(LocalizationService.instance.t('navigation.selectLocation')),
-                  onPressed: () {
+                  onPressed: appState.areRoutePointsTooClose ? null : () {
                     debugPrint('[NavigationSheet] Select Location button pressed');
                     appState.selectSecondRoutePoint();
                   },