fix StadiaMaps Dark and add demo.

lib/models/app_settings.dart

@@ -76,6 +76,8 @@ class Cyr2LatProfile {
 
 class AppSettings {
   static const Object _unset = Object();
+  static const String stadiaDemo =
+      '51bd0381-4685-4666-bae8-48940f6d77c0';
 
   final bool clearPathOnMaxRetry;
   final bool mapShowRepeaters;
@@ -125,6 +127,17 @@ class AppSettings {
   final List<Cyr2LatProfile> cyr2latProfiles;
   final String selectedCyr2latProfileId;
 
+  String get effectiveMapTileApiKey {
+    final apiKey = mapTileApiKey?.trim();
+    if (apiKey == null || apiKey.isEmpty) {
+      return stadiaDemo;
+    }
+    return apiKey;
+  }
+
+  bool get usesstadiaDemo =>
+      effectiveMapTileApiKey == stadiaDemo;
+
   Map<String, String> get cyr2latCharMap {
     final profile = cyr2latProfiles.firstWhere(
       (p) => p.id == selectedCyr2latProfileId,

lib/screens/app_settings_screen.dart

@@ -1019,11 +1019,9 @@ class AppSettingsScreen extends StatelessWidget {
   }
 
   String _mapApiKeySummary(BuildContext context, AppSettings settings) {
-    final apiKey = settings.mapTileApiKey?.trim();
-    if (apiKey == null || apiKey.isEmpty) {
-      return context.l10n.appSettings_stadiaApiKeyRequired;
-    }
-    return context.l10n.appSettings_stadiaApiKeyConfigured(_maskApiKey(apiKey));
+    return context.l10n.appSettings_stadiaApiKeyConfigured(
+      _maskApiKey(settings.effectiveMapTileApiKey),
+    );
   }
 
   String _maskApiKey(String value) {
@@ -1153,9 +1151,13 @@ class AppSettingsScreen extends StatelessWidget {
     BuildContext context,
     AppSettingsService settingsService,
   ) {
-    final controller = TextEditingController(
-      text: settingsService.settings.mapTileApiKey ?? '',
+    final currentApiKey = settingsService.settings.mapTileApiKey?.trim() ?? '';
+    final maskedApiKey = _maskApiKey(
+      currentApiKey.isEmpty
+          ? AppSettings.stadiaDemo
+          : currentApiKey,
     );
+    final controller = TextEditingController(text: maskedApiKey);
     showDialog(
       context: context,
       builder: (dialogContext) => AlertDialog(
@@ -1173,6 +1175,7 @@ class AppSettingsScreen extends StatelessWidget {
                 autofocus: true,
                 autocorrect: false,
                 enableSuggestions: false,
+                autofillHints: const [AutofillHints.password],
                 decoration: const InputDecoration(
                   border: OutlineInputBorder(),
                   hintText: '4e1bf343-3d91-4d9c-a8e1-1234567890ab',
@@ -1188,7 +1191,10 @@ class AppSettingsScreen extends StatelessWidget {
           ),
           TextButton(
             onPressed: () async {
-              await settingsService.setMapTileApiKey(controller.text);
+              final apiKey = controller.text.trim();
+              await settingsService.setMapTileApiKey(
+                apiKey == maskedApiKey ? currentApiKey : apiKey,
+              );
               if (!dialogContext.mounted) return;
               Navigator.pop(dialogContext);
             },

lib/services/map_tile_cache_service.dart

@@ -305,8 +305,22 @@ class MapTileCacheService extends ChangeNotifier {
     appSettingsService.addListener(_handleSettingsChanged);
   }
 
-  MapRasterSourceDefinition get source =>
-      MapRasterSourceCatalog.fromSettings(appSettingsService.settings);
+  MapRasterSourceDefinition get source {
+    final selectedSource = MapRasterSourceCatalog.fromSettings(
+      appSettingsService.settings,
+    );
+    if (!selectedSource.allowsBulkDownload ||
+        !appSettingsService.settings.usesstadiaDemo) {
+      return selectedSource;
+    }
+    return MapRasterSourceDefinition(
+      id: selectedSource.id,
+      label: selectedSource.label,
+      description: selectedSource.description,
+      isStadia: selectedSource.isStadia,
+      allowsBulkDownload: false, // Explicitly disable bulk download for demo.
+    );
+  }
 
   MapRasterEndpointDefinition get endpoint =>
       MapRasterEndpointCatalog.fromSettings(appSettingsService.settings);
@@ -315,6 +329,26 @@ class MapTileCacheService extends ChangeNotifier {
 
   TileBuilder? get tileBuilder => null;
 
+  static bool shouldApplyDarkFilterForSettings(
+    AppSettings settings,
+    Brightness brightness,
+  ) {
+    switch (MapRasterSourcePreset.fromId(settings.mapRasterSourceId)) {
+      case MapRasterSourcePreset.osmDark:
+      case MapRasterSourcePreset.outdoorsDark:
+      case MapRasterSourcePreset.osmBrightDark:
+        return true;
+      case MapRasterSourcePreset.osmAuto:
+        return brightness == Brightness.dark;
+      case MapRasterSourcePreset.osmStandard:
+      case MapRasterSourcePreset.stamenTerrain:
+      case MapRasterSourcePreset.alidadeSmoothDark:
+      case MapRasterSourcePreset.outdoors:
+      case MapRasterSourcePreset.osmBright:
+        return false;
+    }
+  }
+
   static const ColorFilter _darkMapFilter = ColorFilter.matrix([
     -0.0850,
     -0.2861,
@@ -345,7 +379,6 @@ class MapTileCacheService extends ChangeNotifier {
   };
 
   Widget buildTileLayer(BuildContext context, {double opacity = 1}) {
-    final source = this.source;
     Widget layer = TileLayer(
       urlTemplate: urlTemplate,
       tileProvider: tileProvider,
@@ -354,12 +387,10 @@ class MapTileCacheService extends ChangeNotifier {
       maxZoom: 19,
     );
 
-    final shouldApplyDarkFilter =
-        source == MapRasterSourceCatalog.osmDark ||
-        source == MapRasterSourceCatalog.outdoorsDark ||
-        source == MapRasterSourceCatalog.osmBrightDark ||
-        (source == MapRasterSourceCatalog.osmAuto &&
-            Theme.of(context).brightness == Brightness.dark);
+    final shouldApplyDarkFilter = shouldApplyDarkFilterForSettings(
+      appSettingsService.settings,
+      Theme.of(context).brightness,
+    );
 
     if (shouldApplyDarkFilter) {
       layer = ColorFiltered(colorFilter: _darkMapFilter, child: layer);
@@ -608,12 +639,9 @@ class MapTileCacheService extends ChangeNotifier {
       return 'https://tile.openstreetmap.org/{z}/{x}/{y}.png';
     }
     final endpoint = MapRasterEndpointCatalog.fromSettings(settings);
-    final apiKey = settings.mapTileApiKey?.trim();
+    final apiKey = settings.effectiveMapTileApiKey;
     final base =
         'https://${endpoint.host}/tiles/${source.id}/{z}/{x}/{y}${endpoint.scaleSuffix}.png';
-    if (apiKey == null || apiKey.isEmpty) {
-      return base;
-    }
     final query = Uri(queryParameters: {'api_key': apiKey}).query;
     return '$base?$query';
   }