feat: 添加自定义字体功能，支持字体选择和应用

lib/main.dart

@@ -14,6 +14,7 @@ import 'package:PiliPlus/services/download/download_service.dart';
 import 'package:PiliPlus/services/service_locator.dart';
 import 'package:PiliPlus/utils/cache_manager.dart';
 import 'package:PiliPlus/utils/calc_window_position.dart';
+import 'package:PiliPlus/utils/app_font.dart';
 import 'package:PiliPlus/utils/date_utils.dart';
 import 'package:PiliPlus/utils/extension/iterable_ext.dart';
 import 'package:PiliPlus/utils/extension/theme_ext.dart';
@@ -96,6 +97,7 @@ void main() async {
     if (kDebugMode) debugPrint('GStorage init error: $e');
     exit(0);
   }
+  await AppFont.init();
   ScaledWidgetsFlutterBinding.instance.scaleFactor = Pref.uiScale;
   await Future.wait([_initDownPath(), _initTmpPath()]);
   Get

lib/pages/setting/models/style_settings.dart

@@ -26,6 +26,7 @@ import 'package:PiliPlus/pages/setting/widgets/multi_select_dialog.dart';
 import 'package:PiliPlus/pages/setting/widgets/select_dialog.dart';
 import 'package:PiliPlus/pages/setting/widgets/slider_dialog.dart';
 import 'package:PiliPlus/plugin/pl_player/utils/fullscreen.dart';
+import 'package:PiliPlus/utils/app_font.dart';
 import 'package:PiliPlus/utils/extension/file_ext.dart';
 import 'package:PiliPlus/utils/extension/num_ext.dart';
 import 'package:PiliPlus/utils/extension/theme_ext.dart';
@@ -156,6 +157,12 @@ List<SettingsModel> get styleSettings => [
     onChanged: (value) => Get.forceAppUpdate(),
     onTap: _showFontWeightDialog,
   ),
+  NormalModel(
+    title: '应用字体',
+    leading: const Icon(Icons.font_download_outlined),
+    getSubtitle: () => AppFont.currentFontName ?? '系统字体',
+    onTap: _showCustomFontDialog,
+  ),
   NormalModel(
     title: '界面缩放',
     getSubtitle: () => '当前缩放比例：${Pref.uiScale.toStringAsFixed(2)}',
@@ -488,6 +495,66 @@ void _showQualityDialog({
   });
 }
 
+Future<void> _showCustomFontDialog(
+  BuildContext context,
+  VoidCallback setState,
+) async {
+  final pageContext = context;
+  await showDialog<void>(
+    context: pageContext,
+    builder: (dialogContext) => AlertDialog(
+      title: const Text('应用字体'),
+      content: Text(
+        AppFont.currentFontName == null
+            ? '当前使用系统字体。'
+            : '当前字体：${AppFont.currentFontName}',
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.of(dialogContext).pop(),
+          child: const Text('取消'),
+        ),
+        TextButton(
+          onPressed: () async {
+            Navigator.of(dialogContext).pop();
+            final cleared = await AppFont.clear();
+            if (!pageContext.mounted) {
+              return;
+            }
+            if (cleared) {
+              setState();
+              Get.forceAppUpdate();
+              SmartDialog.showToast('已恢复为系统字体');
+            } else {
+              SmartDialog.showToast('当前已经是系统字体');
+            }
+          },
+          child: const Text('系统字体'),
+        ),
+        FilledButton(
+          onPressed: () async {
+            Navigator.of(dialogContext).pop();
+            try {
+              final changed = await AppFont.pickAndApply();
+              if (!pageContext.mounted) {
+                return;
+              }
+              if (changed) {
+                setState();
+                Get.forceAppUpdate();
+                SmartDialog.showToast('自定义字体已应用');
+              }
+            } catch (e) {
+              SmartDialog.showToast('字体加载失败: $e');
+            }
+          },
+          child: const Text('选择字体'),
+        ),
+      ],
+    ),
+  );
+}
+
 void _showUiScaleDialog(
   BuildContext context,
   VoidCallback setState,

lib/utils/app_font.dart

@@ -0,0 +1,158 @@
+import 'dart:io';
+
+import 'package:PiliPlus/utils/path_utils.dart';
+import 'package:PiliPlus/utils/storage.dart';
+import 'package:PiliPlus/utils/storage_key.dart';
+import 'package:PiliPlus/utils/storage_pref.dart';
+import 'package:file_picker/file_picker.dart';
+import 'package:flutter/services.dart';
+import 'package:path/path.dart' as path;
+
+abstract final class AppFont {
+  static const List<String> allowedExtensions = ['ttf', 'otf'];
+  static const String _fontDirName = 'fonts';
+
+  static String? get currentFontName => Pref.customFontName;
+
+  static Future<void> init() async {
+    final fontPath = Pref.customFontPath;
+    final fontFamily = Pref.customFontFamily;
+    if (fontPath == null || fontFamily == null) {
+      await _cleanupFontDir();
+      return;
+    }
+
+    final file = File(fontPath);
+    if (!file.existsSync()) {
+      await clear();
+      return;
+    }
+
+    try {
+      await _loadFont(fontPath: fontPath, fontFamily: fontFamily);
+      await _cleanupFontDir(excludePath: fontPath);
+    } catch (_) {
+      await clear();
+    }
+  }
+
+  static Future<bool> pickAndApply() async {
+    final result = await FilePicker.platform.pickFiles(
+      type: FileType.custom,
+      allowedExtensions: allowedExtensions,
+      withData: true,
+    );
+    if (result == null || result.files.isEmpty) {
+      return false;
+    }
+
+    final picked = result.files.single;
+    final extension = path
+        .extension(picked.path ?? picked.name)
+        .replaceFirst('.', '')
+        .toLowerCase();
+    if (!allowedExtensions.contains(extension)) {
+      throw UnsupportedError('unsupported font file: $extension');
+    }
+
+    final fontDir = Directory(path.join(appSupportDirPath, _fontDirName));
+    if (!fontDir.existsSync()) {
+      await fontDir.create(recursive: true);
+    }
+
+    final timestamp = DateTime.now().millisecondsSinceEpoch;
+    final targetPath = path.join(fontDir.path, 'custom_font_$timestamp.$extension');
+    final targetFile = File(targetPath);
+    if (picked.bytes case final Uint8List bytes) {
+      await targetFile.writeAsBytes(bytes, flush: true);
+    } else if (picked.path case final String sourcePath) {
+      await File(sourcePath).copy(targetPath);
+    } else {
+      throw StateError('missing font bytes');
+    }
+
+    final fontFamily = 'custom_font_$timestamp';
+    try {
+      await _loadFont(fontPath: targetPath, fontFamily: fontFamily);
+      final previousFontPath = Pref.customFontPath;
+      await GStorage.setting.put(SettingBoxKey.customFontPath, targetPath);
+      await GStorage.setting.put(SettingBoxKey.customFontFamily, fontFamily);
+      await GStorage.setting.put(
+        SettingBoxKey.customFontName,
+        path.basename(picked.path ?? picked.name),
+      );
+      if (previousFontPath != null && previousFontPath != targetPath) {
+        final previousFile = File(previousFontPath);
+        if (previousFile.existsSync()) {
+          try {
+            await previousFile.delete();
+          } catch (_) {}
+        }
+      }
+      await _cleanupFontDir(excludePath: targetPath);
+      return true;
+    } catch (_) {
+      if (targetFile.existsSync()) {
+        await targetFile.delete();
+      }
+      rethrow;
+    }
+  }
+
+  static Future<bool> clear() async {
+    final fontPath = Pref.customFontPath;
+    final hadCustomFont =
+        (fontPath != null && fontPath.isNotEmpty) ||
+        Pref.customFontFamily != null ||
+        Pref.customFontName != null;
+    await GStorage.setting.delete(SettingBoxKey.customFontPath);
+    await GStorage.setting.delete(SettingBoxKey.customFontFamily);
+    await GStorage.setting.delete(SettingBoxKey.customFontName);
+    if (fontPath != null && fontPath.isNotEmpty) {
+      final file = File(fontPath);
+      if (file.existsSync()) {
+        try {
+          await file.delete();
+        } catch (_) {}
+      }
+    }
+    final deletedFiles = await _cleanupFontDir();
+    return hadCustomFont || deletedFiles;
+  }
+
+  static Future<void> _loadFont({
+    required String fontPath,
+    required String fontFamily,
+  }) async {
+    final bytes = await File(fontPath).readAsBytes();
+    await (FontLoader(fontFamily)
+          ..addFont(Future.value(ByteData.sublistView(bytes))))
+        .load();
+  }
+
+  static Future<bool> _cleanupFontDir({String? excludePath}) async {
+    final fontDir = Directory(path.join(appSupportDirPath, _fontDirName));
+    if (!fontDir.existsSync()) {
+      return false;
+    }
+
+    var deletedAny = false;
+    await for (final entity in fontDir.list()) {
+      if (entity is! File) {
+        continue;
+      }
+      if (excludePath != null && path.equals(entity.path, excludePath)) {
+        continue;
+      }
+      final extension = path.extension(entity.path).replaceFirst('.', '').toLowerCase();
+      if (!allowedExtensions.contains(extension)) {
+        continue;
+      }
+      try {
+        await entity.delete();
+        deletedAny = true;
+      } catch (_) {}
+    }
+    return deletedAny;
+  }
+}

lib/utils/storage_key.dart

@@ -221,6 +221,9 @@ abstract final class SettingBoxKey {
 
   static const String themeMode = 'themeMode',
       defaultTextScale = 'textScale',
+      customFontPath = 'customFontPath',
+      customFontFamily = 'customFontFamily',
+      customFontName = 'customFontName',
       dynamicColor = 'dynamicColor',
       customColor = 'customColor',
       displayMode = 'displayMode',

lib/utils/storage_pref.dart

@@ -564,6 +564,19 @@ abstract final class Pref {
   static int get appFontWeight =>
       _setting.get(SettingBoxKey.appFontWeight, defaultValue: -1);
 
+  static String? get customFontPath =>
+      _setting.get(SettingBoxKey.customFontPath);
+
+  static String? get customFontFamily {
+    final value = _setting.get(SettingBoxKey.customFontFamily, defaultValue: '');
+    return value is String && value.isNotEmpty ? value : null;
+  }
+
+  static String? get customFontName {
+    final value = _setting.get(SettingBoxKey.customFontName, defaultValue: '');
+    return value is String && value.isNotEmpty ? value : null;
+  }
+
   static bool get enableDragSubtitle =>
       _setting.get(SettingBoxKey.enableDragSubtitle, defaultValue: false);
 

lib/utils/theme_utils.dart

@@ -11,18 +11,23 @@ abstract final class ThemeUtils {
     required bool isDynamic,
     bool isDark = false,
   }) {
+    final customFontFamily = Pref.customFontFamily;
     final appFontWeight = Pref.appFontWeight.clamp(
       -1,
       FontWeight.values.length - 1,
     );
     final fontWeight = appFontWeight == -1
         ? null
         : FontWeight.values[appFontWeight];
-    late final textStyle = TextStyle(fontWeight: fontWeight);
+    late final textStyle = TextStyle(
+      fontWeight: fontWeight,
+      fontFamily: customFontFamily,
+    );
     ThemeData themeData = ThemeData(
       colorScheme: colorScheme,
+      fontFamily: customFontFamily,
       useMaterial3: true,
-      textTheme: fontWeight == null
+      textTheme: fontWeight == null && customFontFamily == null
           ? null
           : TextTheme(
               displayLarge: textStyle,
@@ -41,7 +46,7 @@ abstract final class ThemeUtils {
               labelMedium: textStyle,
               labelSmall: textStyle,
             ),
-      tabBarTheme: fontWeight == null
+      tabBarTheme: fontWeight == null && customFontFamily == null
           ? null
           : TabBarThemeData(labelStyle: textStyle),
       appBarTheme: AppBarTheme(
@@ -53,6 +58,7 @@ abstract final class ThemeUtils {
         titleTextStyle: TextStyle(
           fontSize: 16,
           color: colorScheme.onSurface,
+          fontFamily: customFontFamily,
           fontWeight: fontWeight,
         ),
       ),
@@ -88,6 +94,7 @@ abstract final class ThemeUtils {
         titleTextStyle: TextStyle(
           fontSize: 18,
           color: colorScheme.onSurface,
+          fontFamily: customFontFamily,
           fontWeight: fontWeight,
         ),
         backgroundColor: colorScheme.surface,
@@ -130,6 +137,14 @@ abstract final class ThemeUtils {
         },
       ),
     );
+    if (customFontFamily != null) {
+      themeData = themeData.copyWith(
+        textTheme: themeData.textTheme.apply(fontFamily: customFontFamily),
+        primaryTextTheme: themeData.primaryTextTheme.apply(
+          fontFamily: customFontFamily,
+        ),
+      );
+    }
     if (isDark) {
       if (Pref.isPureBlackTheme) {
         themeData = darkenTheme(themeData);