feat(appearance): support imported TTF and OTF fonts

lib/l10n/arb/app_en.arb

@@ -7152,6 +7152,10 @@
   "playbackPauseOnMuteDescription": "Pause at zero media volume and resume when raised. Manual pauses stay paused. Standard audio output only.",
   "playbackOnHeadphonesConnected": "Play when headphones connect",
   "playbackOnHeadphonesConnectedDescription": "Resume the current song when wired or Bluetooth headphones connect. Disconnecting pauses playback. Built-in player only.",
+  "appearanceCustomFont": "Custom font",
+  "appearanceCustomFontSubtitle": "Import a TTF or OTF file (up to 10 MB). Overrides the theme and system font.",
+  "appearanceCustomFontInvalid": "Could not load this font. Choose a valid TTF or OTF file up to 10 MB.",
+  "appearanceCustomFontReset": "Use theme font",
   "optionsEmbeddedCoverSizeOriginal": "Original resolution",
   "@optionsEmbeddedCoverSizeOriginal": {
     "description": "Option that preserves the provider artwork at its original resolution"

lib/l10n/arb/app_id.arb

@@ -7165,6 +7165,10 @@
   "artistUpcomingConcerts": "Konser Mendatang",
   "artistAllUpcomingConcerts": "Semua Konser Mendatang",
   "artistNoUpcomingConcerts": "Tiada konser mendatang.",
+  "appearanceCustomFont": "Font kustom",
+  "appearanceCustomFontSubtitle": "Impor file TTF atau OTF (maksimal 10 MB). Menggantikan font tema dan sistem.",
+  "appearanceCustomFontInvalid": "Font tidak dapat dimuat. Pilih file TTF atau OTF yang valid, maksimal 10 MB.",
+  "appearanceCustomFontReset": "Gunakan font tema",
   "optionsEmbeddedCoverSizeOriginal": "Resolusi asli",
   "@optionsEmbeddedCoverSizeOriginal": {
     "description": "Option that preserves the provider artwork at its original resolution"

lib/models/theme_settings.dart

@@ -7,6 +7,8 @@ const String kUseAmoledKey = 'use_amoled';
 const String kThemeStyleKey = 'theme_style';
 const String kMornyeAccentKey = 'mornye_accent';
 const String kUseSystemFontKey = 'use_system_font';
+const String kCustomFontIdKey = 'custom_font_id';
+const String kCustomFontNameKey = 'custom_font_name';
 const String kMornyeGlassClarityKey = 'mornye_glass_clarity';
 const String kMornyeGlassOutlinesKey = 'mornye_glass_outlines';
 const double kDefaultMornyeGlassClarity = 0.75;
@@ -43,6 +45,8 @@ class ThemeSettings {
   final AppThemeStyle style;
   final MornyeAccent mornyeAccent;
   final bool useSystemFont;
+  final String customFontId;
+  final String customFontName;
   final double mornyeGlassClarity;
   final bool mornyeGlassOutlines;
 
@@ -54,6 +58,8 @@ class ThemeSettings {
     this.style = AppThemeStyle.material,
     this.mornyeAccent = MornyeAccent.red,
     this.useSystemFont = false,
+    this.customFontId = '',
+    this.customFontName = '',
     this.mornyeGlassClarity = kDefaultMornyeGlassClarity,
     this.mornyeGlassOutlines = true,
   });
@@ -68,6 +74,8 @@ class ThemeSettings {
     AppThemeStyle? style,
     MornyeAccent? mornyeAccent,
     bool? useSystemFont,
+    String? customFontId,
+    String? customFontName,
     double? mornyeGlassClarity,
     bool? mornyeGlassOutlines,
   }) {
@@ -79,6 +87,8 @@ class ThemeSettings {
       style: style ?? this.style,
       mornyeAccent: mornyeAccent ?? this.mornyeAccent,
       useSystemFont: useSystemFont ?? this.useSystemFont,
+      customFontId: customFontId ?? this.customFontId,
+      customFontName: customFontName ?? this.customFontName,
       mornyeGlassClarity: normalizeMornyeGlassClarity(
         mornyeGlassClarity ?? this.mornyeGlassClarity,
       ),
@@ -94,6 +104,8 @@ class ThemeSettings {
     kThemeStyleKey: style.name,
     kMornyeAccentKey: mornyeAccent.name,
     kUseSystemFontKey: useSystemFont,
+    kCustomFontIdKey: customFontId,
+    kCustomFontNameKey: customFontName,
     kMornyeGlassClarityKey: mornyeGlassClarity,
     kMornyeGlassOutlinesKey: mornyeGlassOutlines,
   };
@@ -107,6 +119,8 @@ class ThemeSettings {
       style: themeStyleFromString(json[kThemeStyleKey] as String?),
       mornyeAccent: mornyeAccentFromString(json[kMornyeAccentKey] as String?),
       useSystemFont: json[kUseSystemFontKey] as bool? ?? false,
+      customFontId: json[kCustomFontIdKey] as String? ?? '',
+      customFontName: json[kCustomFontNameKey] as String? ?? '',
       mornyeGlassClarity: normalizeMornyeGlassClarity(
         json[kMornyeGlassClarityKey] as num?,
       ),
@@ -125,6 +139,8 @@ class ThemeSettings {
         other.style == style &&
         other.mornyeAccent == mornyeAccent &&
         other.useSystemFont == useSystemFont &&
+        other.customFontId == customFontId &&
+        other.customFontName == customFontName &&
         other.mornyeGlassClarity == mornyeGlassClarity &&
         other.mornyeGlassOutlines == mornyeGlassOutlines;
   }
@@ -138,6 +154,8 @@ class ThemeSettings {
       style.hashCode ^
       mornyeAccent.hashCode ^
       useSystemFont.hashCode ^
+      customFontId.hashCode ^
+      customFontName.hashCode ^
       mornyeGlassClarity.hashCode ^
       mornyeGlassOutlines.hashCode;
 }

lib/providers/custom_font_provider.dart

@@ -0,0 +1,8 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:spotiflac_android/providers/theme_provider.dart';
+import 'package:spotiflac_android/services/custom_font_service.dart';
+
+final customFontFamilyProvider = FutureProvider<String?>((ref) {
+  final id = ref.watch(themeProvider.select((theme) => theme.customFontId));
+  return CustomFontService.instance.restore(id);
+});

lib/providers/theme_provider.dart

@@ -16,6 +16,8 @@ ThemeSettings loadBootstrapThemeSettings(SharedPreferences prefs) {
     style: themeStyleFromString(prefs.getString(kThemeStyleKey)),
     mornyeAccent: mornyeAccentFromString(prefs.getString(kMornyeAccentKey)),
     useSystemFont: prefs.getBool(kUseSystemFontKey) ?? false,
+    customFontId: prefs.getString(kCustomFontIdKey) ?? '',
+    customFontName: prefs.getString(kCustomFontNameKey) ?? '',
     mornyeGlassClarity: normalizeMornyeGlassClarity(
       prefs.getDouble(kMornyeGlassClarityKey),
     ),
@@ -77,6 +79,8 @@ class ThemeNotifier extends Notifier<ThemeSettings> {
       await prefs.setString(kThemeStyleKey, snapshot.style.name);
       await prefs.setString(kMornyeAccentKey, snapshot.mornyeAccent.name);
       await prefs.setBool(kUseSystemFontKey, snapshot.useSystemFont);
+      await prefs.setString(kCustomFontIdKey, snapshot.customFontId);
+      await prefs.setString(kCustomFontNameKey, snapshot.customFontName);
       await prefs.setDouble(
         kMornyeGlassClarityKey,
         snapshot.mornyeGlassClarity,
@@ -125,6 +129,13 @@ class ThemeNotifier extends Notifier<ThemeSettings> {
     await _saveToStorage();
   }
 
+  Future<void> setCustomFont(String id, String name) async {
+    _editState(
+      (current) => current.copyWith(customFontId: id, customFontName: name),
+    );
+    await _saveToStorage();
+  }
+
   Future<void> setMornyeGlassClarity(
     double value, {
     bool persist = true,

lib/screens/settings/appearance_settings_page.dart

@@ -12,6 +12,7 @@ import 'package:spotiflac_android/widgets/mornye_chrome.dart';
 import 'package:spotiflac_android/utils/adaptive_layout.dart';
 import 'package:spotiflac_android/widgets/settings_group.dart';
 import 'package:spotiflac_android/widgets/app_sliver_header.dart';
+import 'package:spotiflac_android/widgets/custom_font_setting.dart';
 
 class AppearanceSettingsPage extends ConsumerWidget {
   const AppearanceSettingsPage({super.key});
@@ -208,6 +209,7 @@ class AppearanceSettingsPage extends ConsumerWidget {
                         .read(settingsProvider.notifier)
                         .setHeroAnimationsEnabled(value),
                   ),
+                  const CustomFontSetting(),
                   SettingsSwitchItem(
                     icon: Icons.blur_on,
                     title: context.l10n.appearanceForceBlur,

lib/services/custom_font_service.dart

@@ -0,0 +1,96 @@
+import 'dart:io';
+
+import 'package:crypto/crypto.dart';
+import 'package:flutter/services.dart';
+import 'package:path_provider/path_provider.dart';
+
+/// Copies imported fonts into app storage; never persists a picker/container path.
+class CustomFontService {
+  CustomFontService({
+    Future<Directory> Function()? directory,
+    Future<void> Function(String, Uint8List)? loadFont,
+  }) : _directory = directory ?? _fontDirectory,
+       _loadFont = loadFont ?? _register;
+
+  static const maxBytes = 10 * 1024 * 1024;
+  static final instance = CustomFontService();
+  final Future<Directory> Function() _directory;
+  final Future<void> Function(String, Uint8List) _loadFont;
+  final Map<String, Future<String>> _loads = {};
+  static final _idPattern = RegExp(r'^[a-f0-9]{64}$');
+
+  static Future<Directory> _fontDirectory() async => Directory(
+    '${(await getApplicationSupportDirectory()).path}/custom_fonts',
+  ).create(recursive: true);
+
+  static Future<void> _register(String family, Uint8List bytes) async {
+    final loader = FontLoader(family)
+      ..addFont(Future.value(ByteData.sublistView(bytes)));
+    await loader.load();
+  }
+
+  static void validate(Uint8List bytes) {
+    if (bytes.length < 12 || bytes.length > maxBytes) {
+      throw const FormatException('Invalid font size');
+    }
+    final data = ByteData.sublistView(bytes);
+    final signature = data.getUint32(0);
+    if (signature != 0x00010000 && signature != 0x4f54544f) {
+      throw const FormatException('Expected a TTF or OTF font');
+    }
+    final count = data.getUint16(4);
+    if (count == 0 || 12 + count * 16 > bytes.length) {
+      throw const FormatException('Invalid font table directory');
+    }
+    for (var i = 0; i < count; i++) {
+      final table = 12 + i * 16;
+      final offset = data.getUint32(table + 8);
+      final length = data.getUint32(table + 12);
+      if (offset > bytes.length || length > bytes.length - offset) {
+        throw const FormatException('Truncated font table');
+      }
+    }
+  }
+
+  Future<String> import(Uint8List bytes) async {
+    validate(bytes);
+    final id = sha256.convert(bytes).toString();
+    await _load(id, bytes);
+    final directory = await _directory();
+    final destination = File('${directory.path}/$id.font');
+    if (!await destination.exists()) {
+      final staged = await File(
+        '${directory.path}/$id.tmp',
+      ).writeAsBytes(bytes, flush: true);
+      await staged.rename(destination.path);
+    }
+    return id;
+  }
+
+  Future<String> _load(String id, Uint8List bytes) =>
+      _loads.putIfAbsent(id, () async {
+        final family = 'ImportedFont_$id';
+        try {
+          await _loadFont(family, bytes);
+          return family;
+        } catch (_) {
+          _loads.remove(id);
+          rethrow;
+        }
+      });
+
+  Future<String?> restore(String id) async {
+    if (!_idPattern.hasMatch(id)) return null;
+    try {
+      final file = File('${(await _directory()).path}/$id.font');
+      if (await file.length() > maxBytes) return null;
+      final bytes = await file.readAsBytes();
+      validate(bytes);
+      if (sha256.convert(bytes).toString() != id) return null;
+      return await _load(id, bytes);
+    } catch (_) {
+      // Missing fonts after restoring preferences fall back to the theme font.
+      return null;
+    }
+  }
+}

lib/theme/app_theme.dart

@@ -31,6 +31,7 @@ class AppTheme {
     ColorScheme? dynamicScheme,
     Color? seedColor,
     bool useSystemFont = false,
+    String? fontFamily,
   }) {
     final scheme =
         dynamicScheme ??
@@ -61,7 +62,7 @@ class AppTheme {
       chipTheme: _chipTheme(scheme),
       dividerTheme: _dividerTheme(scheme),
       extensions: const <ThemeExtension<dynamic>>[AppTokens.standard],
-      fontFamily: useSystemFont ? null : 'Google Sans Flex',
+      fontFamily: fontFamily ?? (useSystemFont ? null : 'Google Sans Flex'),
     );
   }
 
@@ -70,6 +71,7 @@ class AppTheme {
     Color? seedColor,
     bool isAmoled = false,
     bool useSystemFont = false,
+    String? fontFamily,
   }) {
     final scheme =
         dynamicScheme ??
@@ -101,7 +103,7 @@ class AppTheme {
       chipTheme: _chipTheme(scheme),
       dividerTheme: _dividerTheme(scheme),
       extensions: const <ThemeExtension<dynamic>>[AppTokens.standard],
-      fontFamily: useSystemFont ? null : 'Google Sans Flex',
+      fontFamily: fontFamily ?? (useSystemFont ? null : 'Google Sans Flex'),
     );
   }
 

lib/theme/dynamic_color_wrapper.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:dynamic_color/dynamic_color.dart';
 import 'package:material_ui/material_ui.dart' as material_ui;
 import 'package:spotiflac_android/providers/theme_provider.dart';
+import 'package:spotiflac_android/providers/custom_font_provider.dart';
 import 'package:spotiflac_android/theme/app_theme.dart';
 import 'package:spotiflac_android/models/theme_settings.dart';
 import 'package:spotiflac_android/theme/mornye_theme.dart';
@@ -16,6 +17,7 @@ class DynamicColorWrapper extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final themeSettings = ref.watch(themeProvider);
+    final fontFamily = ref.watch(customFontFamilyProvider).asData?.value;
 
     if (themeSettings.style == AppThemeStyle.mornye) {
       return builder(
@@ -23,6 +25,7 @@ class DynamicColorWrapper extends ConsumerWidget {
           Brightness.light,
           accent: themeSettings.mornyeAccent,
           useSystemFont: themeSettings.useSystemFont,
+          fontFamily: fontFamily,
           glassClarity: themeSettings.mornyeGlassClarity,
           glassOutlines: themeSettings.mornyeGlassOutlines,
         ),
@@ -30,6 +33,7 @@ class DynamicColorWrapper extends ConsumerWidget {
           Brightness.dark,
           accent: themeSettings.mornyeAccent,
           useSystemFont: themeSettings.useSystemFont,
+          fontFamily: fontFamily,
           glassClarity: themeSettings.mornyeGlassClarity,
           glassOutlines: themeSettings.mornyeGlassOutlines,
         ),
@@ -66,11 +70,13 @@ class DynamicColorWrapper extends ConsumerWidget {
         final lightTheme = AppTheme.light(
           dynamicScheme: lightScheme,
           useSystemFont: themeSettings.useSystemFont,
+          fontFamily: fontFamily,
         );
         final darkTheme = AppTheme.dark(
           dynamicScheme: darkScheme,
           isAmoled: themeSettings.useAmoled,
           useSystemFont: themeSettings.useSystemFont,
+          fontFamily: fontFamily,
         );
 
         return builder(lightTheme, darkTheme, themeSettings.themeMode);

lib/theme/mornye_theme.dart

@@ -13,6 +13,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
     this.chromeSurface,
     this.accent = MornyeAccent.red,
     this.useSystemFont = false,
+    this.fontFamily,
     this.glassClarity = kDefaultMornyeGlassClarity,
     this.glassOutlines = true,
   });
@@ -20,6 +21,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
   final Color? chromeSurface;
   final MornyeAccent accent;
   final bool useSystemFont;
+  final String? fontFamily;
   final double glassClarity;
   final bool glassOutlines;
 
@@ -118,13 +120,17 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
   // many artists cannot grow the cache indefinitely. Platform is part of the
   // key because it controls fonts and route transitions.
   static final _themeCache =
-      <(TargetPlatform, Brightness, Color?, MornyeAccent, bool), ThemeData>{};
+      <
+        (TargetPlatform, Brightness, Color?, MornyeAccent, bool, String?),
+        ThemeData
+      >{};
 
   static ThemeData build(
     Brightness brightness, {
     Color? chromeSurface,
     MornyeAccent accent = MornyeAccent.red,
     bool useSystemFont = false,
+    String? fontFamily,
     double glassClarity = kDefaultMornyeGlassClarity,
     bool glassOutlines = true,
   }) {
@@ -134,6 +140,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
       chromeSurface,
       accent,
       useSystemFont,
+      fontFamily,
     );
     final cached = _themeCache.remove(key);
     if (cached != null) {
@@ -145,6 +152,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
       chromeSurface: chromeSurface,
       selectedAccent: accent,
       useSystemFont: useSystemFont,
+      fontFamily: fontFamily,
     );
     if (_themeCache.length >= 16) {
       _themeCache.remove(_themeCache.keys.first);
@@ -190,6 +198,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
       chromeSurface: chromeSurface,
       accent: preferences?.accent ?? MornyeAccent.red,
       useSystemFont: preferences?.useSystemFont ?? false,
+      fontFamily: preferences?.fontFamily,
       glassClarity: preferences?.glassClarity ?? kDefaultMornyeGlassClarity,
       glassOutlines: preferences?.glassOutlines ?? true,
     );
@@ -200,6 +209,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
     Color? chromeSurface,
     required MornyeAccent selectedAccent,
     required bool useSystemFont,
+    String? fontFamily,
   }) {
     final dark = brightness == Brightness.dark;
     final accent = accentColor(selectedAccent, brightness);
@@ -251,14 +261,18 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
     final text = type.textStyle.copyWith(
       inherit: true,
       color: foreground,
-      fontFamily: apple || useSystemFont ? type.textStyle.fontFamily : 'Inter',
+      fontFamily:
+          fontFamily ??
+          (apple || useSystemFont ? type.textStyle.fontFamily : 'Inter'),
     );
     final display = type.navLargeTitleTextStyle.copyWith(
       inherit: true,
       color: foreground,
-      fontFamily: apple || useSystemFont
-          ? type.navLargeTitleTextStyle.fontFamily
-          : 'Inter',
+      fontFamily:
+          fontFamily ??
+          (apple || useSystemFont
+              ? type.navLargeTitleTextStyle.fontFamily
+              : 'Inter'),
     );
     // Supply complete styles: replacing a Material role with a bare TextStyle
     // loses its system family and retains Material tracking in other roles.
@@ -312,6 +326,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
           chromeSurface: chromeSurface,
           accent: selectedAccent,
           useSystemFont: useSystemFont,
+          fontFamily: fontFamily,
         ),
         tokens,
       ],
@@ -408,12 +423,14 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
     Color? chromeSurface,
     MornyeAccent? accent,
     bool? useSystemFont,
+    String? fontFamily,
     double? glassClarity,
     bool? glassOutlines,
   }) => MornyeTheme(
     chromeSurface: chromeSurface ?? this.chromeSurface,
     accent: accent ?? this.accent,
     useSystemFont: useSystemFont ?? this.useSystemFont,
+    fontFamily: fontFamily ?? this.fontFamily,
     glassClarity: glassClarity ?? this.glassClarity,
     glassOutlines: glassOutlines ?? this.glassOutlines,
   );
@@ -422,6 +439,7 @@ class MornyeTheme extends ThemeExtension<MornyeTheme> {
   MornyeTheme lerp(covariant MornyeTheme? other, double t) => MornyeTheme(
     chromeSurface: Color.lerp(chromeSurface, other?.chromeSurface, t),
     accent: t < 0.5 ? accent : other?.accent ?? accent,
+    fontFamily: t < 0.5 ? fontFamily : other?.fontFamily,
     useSystemFont: t < 0.5
         ? useSystemFont
         : other?.useSystemFont ?? useSystemFont,

lib/widgets/custom_font_setting.dart

@@ -0,0 +1,72 @@
+import 'package:file_picker/file_picker.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:spotiflac_android/l10n/l10n.dart';
+import 'package:spotiflac_android/providers/theme_provider.dart';
+import 'package:spotiflac_android/services/custom_font_service.dart';
+
+class CustomFontSetting extends ConsumerStatefulWidget {
+  const CustomFontSetting({super.key});
+
+  @override
+  ConsumerState<CustomFontSetting> createState() => _CustomFontSettingState();
+}
+
+class _CustomFontSettingState extends ConsumerState<CustomFontSetting> {
+  bool _importing = false;
+
+  Future<void> _import() async {
+    setState(() => _importing = true);
+    try {
+      final file = await FilePicker.pickFile(
+        type: FileType.custom,
+        allowedExtensions: ['ttf', 'otf'],
+      );
+      if (file == null || !mounted) return;
+      if ((await file.length() ?? 0) > CustomFontService.maxBytes) {
+        throw const FormatException('Font exceeds import limit');
+      }
+      final id = await CustomFontService.instance.import(
+        await file.readAsBytes(),
+      );
+      if (!mounted) return;
+      await ref.read(themeProvider.notifier).setCustomFont(id, file.name);
+    } catch (_) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text(context.l10n.appearanceCustomFontInvalid)),
+        );
+      }
+    } finally {
+      if (mounted) setState(() => _importing = false);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = ref.watch(themeProvider);
+    return ListTile(
+      leading: const Icon(Icons.text_fields),
+      title: Text(context.l10n.appearanceCustomFont),
+      subtitle: Text(
+        theme.customFontId.isEmpty
+            ? context.l10n.appearanceCustomFontSubtitle
+            : theme.customFontName,
+      ),
+      onTap: _importing ? null : _import,
+      trailing: _importing
+          ? const SizedBox.square(
+              dimension: 24,
+              child: CircularProgressIndicator(strokeWidth: 2),
+            )
+          : theme.customFontId.isEmpty
+          ? const Icon(Icons.add)
+          : IconButton(
+              tooltip: context.l10n.appearanceCustomFontReset,
+              onPressed: () =>
+                  ref.read(themeProvider.notifier).setCustomFont('', ''),
+              icon: const Icon(Icons.close),
+            ),
+    );
+  }
+}

test/custom_font_test.dart

@@ -0,0 +1,114 @@
+import 'dart:io';
+import 'dart:typed_data';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:spotiflac_android/models/theme_settings.dart';
+import 'package:spotiflac_android/providers/theme_provider.dart';
+import 'package:spotiflac_android/services/custom_font_service.dart';
+import 'package:spotiflac_android/theme/app_theme.dart';
+import 'package:spotiflac_android/theme/mornye_theme.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  test(
+    'import persists a private copy, restores after restart, rejects damage',
+    () async {
+      final directory = await Directory.systemTemp.createTemp('font-import-');
+      addTearDown(() => directory.delete(recursive: true));
+      final bytes = await File('assets/fonts/InterVariable.ttf').readAsBytes();
+      var loads = 0;
+      CustomFontService service() => CustomFontService(
+        directory: () async => directory,
+        loadFont: (_, data) async {
+          loads++;
+          expect(data, bytes);
+        },
+      );
+      final importer = service();
+      final id = await importer.import(bytes);
+      expect(await importer.restore(id), 'ImportedFont_$id');
+      expect(loads, 1);
+      expect(await service().restore(id), 'ImportedFont_$id');
+      expect(loads, 2);
+      await File('${directory.path}/$id.font').writeAsBytes([1, 2]);
+      expect(await service().restore(id), isNull);
+      expect(await service().restore('../outside'), isNull);
+      expect(
+        () => CustomFontService.validate(Uint8List(12)),
+        throwsFormatException,
+      );
+      expect(
+        () => CustomFontService.validate(bytes.sublist(0, 32)),
+        throwsFormatException,
+      );
+    },
+  );
+
+  test('font choice survives bootstrap, export and reset', () async {
+    SharedPreferences.setMockInitialValues({kUseSystemFontKey: true});
+    final container = ProviderContainer();
+    addTearDown(container.dispose);
+    final notifier = container.read(themeProvider.notifier);
+    await notifier.setCustomFont('selected-font', 'My font.ttf');
+    final prefs = await SharedPreferences.getInstance();
+    final theme = loadBootstrapThemeSettings(prefs);
+    expect(theme.customFontId, 'selected-font');
+    expect(theme.customFontName, 'My font.ttf');
+    expect(ThemeSettings.fromJson(theme.toJson()), theme);
+    await notifier.setCustomFont('', '');
+    expect(loadBootstrapThemeSettings(prefs).customFontId, isEmpty);
+    expect(loadBootstrapThemeSettings(prefs).useSystemFont, isTrue);
+  });
+
+  testWidgets(
+    'custom typography survives Mornye local surface reconstruction',
+    (tester) async {
+      final theme = MornyeTheme.build(
+        Brightness.dark,
+        fontFamily: 'ImportedFont_test',
+      );
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: theme,
+          home: Builder(
+            builder: (context) {
+              final surface = MornyeTheme.fromContext(
+                context,
+                chromeSurface: Colors.red,
+              );
+              expect(
+                surface.textTheme.bodyLarge!.fontFamily,
+                'ImportedFont_test',
+              );
+              expect(
+                surface.textTheme.headlineSmall!.fontFamily,
+                'ImportedFont_test',
+              );
+              return const SizedBox();
+            },
+          ),
+        ),
+      );
+      expect(
+        AppTheme.light(
+          fontFamily: 'ImportedFont_test',
+        ).textTheme.bodyMedium!.fontFamily,
+        'ImportedFont_test',
+      );
+      expect(
+        AppTheme.dark(
+          fontFamily: 'ImportedFont_test',
+        ).textTheme.bodyMedium!.fontFamily,
+        'ImportedFont_test',
+      );
+      expect(
+        MornyeTheme.build(Brightness.dark).textTheme.bodyLarge!.fontFamily,
+        isNot('ImportedFont_test'),
+      );
+    },
+  );
+}