added persisted app settings

lib/model/settings.dart

@@ -2,28 +2,38 @@ import '../assets/constants.dart' as constants;
 
 class Settings {
   final String exportDirectoryPath;
+  final bool alwaysExportEnabled;
 
-  Settings._({required this.exportDirectoryPath});
+  Settings._({
+    required this.exportDirectoryPath,
+    required this.alwaysExportEnabled,
+  });
 
   Map<String, dynamic> toJson() {
-    return {'exportDirectoryPath': exportDirectoryPath};
+    return {
+      'exportDirectoryPath': exportDirectoryPath,
+      'alwaysExportEnabled': alwaysExportEnabled,
+    };
   }
 
   factory Settings.fromJson(Map<String, dynamic> json) {
     return Settings._(
       exportDirectoryPath: json['exportDirectoryPath'] as String,
+      alwaysExportEnabled: json['alwaysExportEnabled'] as bool,
     );
   }
 
   factory Settings.defaults() {
     return Settings._(
       exportDirectoryPath: constants.defaultAndroidExportDirectory,
+      alwaysExportEnabled: false,
     );
   }
 
-  Settings copyWith({String? exportDirectoryPath}) {
+  Settings copyWith({String? exportDirectoryPath, bool? alwaysExportEnabled}) {
     return Settings._(
       exportDirectoryPath: exportDirectoryPath ?? this.exportDirectoryPath,
+      alwaysExportEnabled: alwaysExportEnabled ?? this.alwaysExportEnabled,
     );
   }
 }

lib/pages/settings_page.dart

@@ -2,10 +2,12 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:permission_handler/permission_handler.dart';
+import 'package:provider/provider.dart';
 
 import '../l10n/app_localizations.dart';
 import '../service/notifying.dart';
 import '../service/permission_service.dart';
+import '../service/settings_provider.dart';
 import '../service/storage.dart';
 
 class SettingsPage extends StatefulWidget {
@@ -29,10 +31,16 @@ class _SettingsPageState extends State<SettingsPage> {
     super.initState();
   }
 
+  // TODO: Localize
   @override
   Widget build(BuildContext context) {
     final titlePadding = Theme.of(context).listTileTheme.contentPadding!;
-    checkStoragePermission;
+    checkStoragePermission();
+    final alwaysExportEnabled = context
+        .watch<SettingsProvider>()
+        .settings
+        .alwaysExportEnabled;
+
     return Scaffold(
       appBar: AppBar(title: Text(AppLocalizations.of(context)!.settings)),
       body: Center(
@@ -51,9 +59,11 @@ class _SettingsPageState extends State<SettingsPage> {
               SizedBox(height: tileSpacing),
               ListTile(
                 title: Text('Grant storage permisson'),
-                subtitle: Text(
+                subtitle: storagePermissionIsGranted
-                  'For app-data settings to work, you need to grant the app permissions to manage internal storage.',
+                    ? Text('Storage permission granted')
-                ),
+                    : Text(
+                        'For app-data settings to work, you need to grant the app permissions to manage internal storage.',
+                      ),
                 onTap: () => PermissionService.requestStoragePermission,
                 trailing: Icon(Icons.arrow_forward_ios_rounded),
                 enabled: !storagePermissionIsGranted,
@@ -62,7 +72,7 @@ class _SettingsPageState extends State<SettingsPage> {
               ListTile(
                 title: Text(AppLocalizations.of(context)!.import),
                 subtitle: Text('Import app-data from a json file.'),
-                onTap: () => onActivateJsonImportPressed(),
+                onTap: () => onJsonImportPressed(),
                 trailing: Icon(Icons.arrow_forward_ios_rounded),
                 enabled: storagePermissionIsGranted,
               ),
@@ -72,10 +82,39 @@ class _SettingsPageState extends State<SettingsPage> {
                 subtitle: Text(
                   'Export app-data to a json file in the selected directory.',
                 ),
-                onTap: () => onActivateJsonExportPressed(),
+                onTap: () => onJsonExportPressed(),
                 trailing: Icon(Icons.arrow_forward_ios_rounded),
                 enabled: storagePermissionIsGranted,
               ),
+              SizedBox(height: tileSpacing),
+              ListTile(
+                title: Text('Always save to file'),
+                subtitle: Text(
+                  'Export app data to a directory, every time you make a change',
+                ),
+                onTap: () => onAlwaysSaveToJsonPressed(),
+                trailing: Checkbox(
+                  value: alwaysExportEnabled,
+                  onChanged: (value) {
+                    onAlwaysSaveToJsonPressed();
+                  },
+                ),
+                enabled: storagePermissionIsGranted,
+              ),
+              if (alwaysExportEnabled) SizedBox(height: tileSpacing),
+              if (alwaysExportEnabled)
+                ListTile(
+                  title: Text('Change export directory'),
+                  subtitle: Text(
+                    context
+                        .watch<SettingsProvider>()
+                        .settings
+                        .exportDirectoryPath,
+                  ),
+                  onTap: () => onChangeExportDirectoryPressed(),
+                  trailing: Icon(Icons.arrow_forward_ios_rounded),
+                  enabled: storagePermissionIsGranted,
+                ),
             ],
           ),
         ),
@@ -83,23 +122,54 @@ class _SettingsPageState extends State<SettingsPage> {
     );
   }
 
-  void onActivateJsonExportPressed() async {
+  void onJsonExportPressed() async {
-    if (!await PermissionService.storagePermissionStatus.isGranted) return;
+    if (!await checkStoragePermission()) return;
     Storage.exportToJsonFile().then(showExportInfo);
   }
 
-  void onActivateJsonImportPressed() async {
+  void onJsonImportPressed() async {
-    if (!await PermissionService.storagePermissionStatus.isGranted) return;
+    if (!await checkStoragePermission()) return;
     Storage.importFromJsonFile().then(showImportInfo);
   }
 
-  Future<void> get checkStoragePermission async {
+  void onAlwaysSaveToJsonPressed() async {
+    if (context.read<SettingsProvider>().settings.alwaysExportEnabled) {
+      context.read<SettingsProvider>().setExportDirectoryPath('', silent: true);
+      context.read<SettingsProvider>().setAlwaysExportEnabled(false);
+      return;
+    }
+
+    if (!await PermissionService.storagePermissionStatus.isGranted) return;
+    final dir = await Storage.selectDirectoryPath();
+    if (dir.isEmpty || !context.mounted) return;
+
+    // ignore: use_build_context_synchronously
+    context.read<SettingsProvider>().setExportDirectoryPath(dir, silent: true);
+
+    // ignore: use_build_context_synchronously
+    Storage.saveDataToFile().whenComplete(
+      // ignore: use_build_context_synchronously
+      () => context.read<SettingsProvider>().setAlwaysExportEnabled(true),
+    );
+  }
+
+  void onChangeExportDirectoryPressed() async {
+    if (!await PermissionService.storagePermissionStatus.isGranted) return;
+    final dir = await Storage.selectDirectoryPath();
+    if (dir.isEmpty || !context.mounted) return;
+
+    // ignore: use_build_context_synchronously
+    context.read<SettingsProvider>().setExportDirectoryPath(dir);
+  }
+
+  Future<bool> checkStoragePermission() async {
     PermissionService.storagePermissionStatus.then((value) {
-      storagePermissionIsGranted = value.isGranted;
       if (context.mounted && value.isGranted != storagePermissionIsGranted) {
+        storagePermissionIsGranted = value.isGranted;
         setState(() {});
       }
     });
+    return storagePermissionIsGranted;
   }
 
   void showExportInfo(bool success) => Notifying.showSnackbar(

lib/service/json_file_service.dart

@@ -14,21 +14,10 @@ class JsonFileService {
     required List<Bookmark> bookmarks,
   }) async {
     try {
-      final dir = await _directoryPath;
+      final dir = await selectDirectoryPath();
       if (dir.isEmpty) return false;
 
-      final data = {
+      saveDataToFile(collections, bookmarks, dir);
-        'collections': collections.map((c) => c.toJson()).toList(),
-        'bookmarks': bookmarks.map((b) => b.toJson()).toList(),
-      };
-      final json = jsonEncode(data).codeUnits;
-      final file = XFile.fromData(
-        Uint8List.fromList(json),
-        mimeType: 'application/json',
-        name: constants.jsonFileName,
-      );
-
-      file.saveTo('$dir/${constants.jsonFileName}');
     } catch (e) {
       return false;
     }
@@ -65,7 +54,31 @@ class JsonFileService {
     }
   }
 
-  static Future<String> get _directoryPath async {
+  static Future<bool> saveDataToFile(
+    List<Collection> collections,
+    List<Bookmark> bookmarks,
+    String directory,
+  ) async {
+    try {
+      final data = jsonEncode({
+        'collections': collections.map((c) => c.toJson()).toList(),
+        'bookmarks': bookmarks.map((b) => b.toJson()).toList(),
+      }).codeUnits;
+
+      final file = XFile.fromData(
+        Uint8List.fromList(data),
+        mimeType: 'application/json',
+        name: constants.jsonFileName,
+      );
+
+      file.saveTo('$directory/${constants.jsonFileName}');
+    } catch (e) {
+      return false;
+    }
+    return true;
+  }
+
+  static Future<String> selectDirectoryPath() async {
     if (Platform.isAndroid) {
       return await getDirectoryPath(
             initialDirectory: constants.defaultAndroidExportDirectory,

lib/service/settings_provider.dart

@@ -12,9 +12,13 @@ class SettingsProvider extends ChangeNotifier {
 
   void setExportDirectoryPath(String path, {bool silent = false}) {
     _settings = _settings.copyWith(exportDirectoryPath: path);
-    _saveSettings();
+    Storage.saveSettings(_settings);
     if (!silent) notifyListeners();
   }
 
-  void _saveSettings() => Storage.saveSettings(_settings);
+  void setAlwaysExportEnabled(bool enabled, {bool silent = false}) {
+    _settings = _settings.copyWith(alwaysExportEnabled: enabled);
+    Storage.saveSettings(_settings);
+    if (!silent) notifyListeners();
+  }
 }

lib/service/storage.dart

@@ -13,6 +13,7 @@ class Storage {
   static SharedPreferencesWithCache? _prefsWithCache;
   static const String _settingsKey = 'settings';
   static const String _statsKey = 'stats';
+  static Settings _currentSettings = Settings.defaults();
 
   static Future<void> initialize() async {
     _prefsWithCache = await SharedPreferencesWithCache.create(
@@ -31,7 +32,8 @@ class Storage {
     final jsonString = _prefs.getString(_settingsKey);
     if (jsonString != null) {
       final json = jsonDecode(jsonString) as Map<String, dynamic>;
-      return Settings.fromJson(json);
+      _currentSettings = Settings.fromJson(json);
+      return _currentSettings;
     } else {
       final settings = Settings.defaults();
       saveSettings(settings);
@@ -41,6 +43,7 @@ class Storage {
 
   static Future<void> saveSettings(Settings settings) {
     final json = jsonEncode(settings.toJson());
+    _currentSettings = settings;
     return _prefs.setString(_settingsKey, json);
   }
 
@@ -63,11 +66,13 @@ class Storage {
   static Future<void> saveCollections(List<Collection> collections) async {
     final jsonList = collections.map((c) => c.toJson()).toList();
     await _prefs.setString(_collectionsKey, jsonEncode(jsonList));
+    if (_currentSettings.alwaysExportEnabled) saveDataToFile();
   }
 
   static Future<void> saveBookmarks(List<Bookmark> bookmarks) async {
     final jsonList = bookmarks.map((b) => b.toJson()).toList();
     await _prefs.setString(_bookmarksKey, jsonEncode(jsonList));
+    if (_currentSettings.alwaysExportEnabled) saveDataToFile();
   }
 
   static List<Bookmark> loadBookmarksForCollection(int collectionId) {
@@ -196,6 +201,15 @@ class Storage {
     return false;
   }
 
+  static Future<String> selectDirectoryPath() =>
+      JsonFileService.selectDirectoryPath();
+
+  static Future<bool> saveDataToFile() => JsonFileService.saveDataToFile(
+    loadCollections(),
+    loadBookmarks(),
+    _currentSettings.exportDirectoryPath,
+  );
+
   static SharedPreferencesWithCache get _prefs {
     if (_prefsWithCache == null) {
       throw StateError(