added app settings api

lib/main.dart

@@ -7,6 +7,7 @@ import 'pages/collections_list_page.dart';
 import 'pages/search_page.dart';
 import 'pages/settings_page.dart';
 import 'service/search_provider.dart';
+import 'service/settings_provider.dart';
 import 'service/shared_link_provider.dart';
 import 'service/storage.dart';
 import 'service/share_intent_service.dart';
@@ -20,6 +21,7 @@ void main() async {
       providers: [
         ChangeNotifierProvider(create: (_) => SharedLinkProvider()),
         ChangeNotifierProvider(create: (_) => SearchProvider()),
+        ChangeNotifierProvider(create: (_) => SettingsProvider()),
       ],
       child: const MapsBookmarks(),
     ),

lib/model/settings.dart

@@ -0,0 +1,29 @@
+import '../assets/constants.dart' as constants;
+
+class Settings {
+  final String exportDirectoryPath;
+
+  Settings._({required this.exportDirectoryPath});
+
+  Map<String, dynamic> toJson() {
+    return {'exportDirectoryPath': exportDirectoryPath};
+  }
+
+  factory Settings.fromJson(Map<String, dynamic> json) {
+    return Settings._(
+      exportDirectoryPath: json['exportDirectoryPath'] as String,
+    );
+  }
+
+  factory Settings.defaults() {
+    return Settings._(
+      exportDirectoryPath: constants.defaultAndroidExportDirectory,
+    );
+  }
+
+  Settings copyWith({String? exportDirectoryPath}) {
+    return Settings._(
+      exportDirectoryPath: exportDirectoryPath ?? this.exportDirectoryPath,
+    );
+  }
+}

lib/pages/settings_page.dart

@@ -17,55 +17,89 @@ class SettingsPage extends StatefulWidget {
 }
 
 class _SettingsPageState extends State<SettingsPage> {
+  bool storagePermissionIsGranted = false;
+  final tileSpacing = 16.0;
+
+  @override
+  void initState() {
+    PermissionService.storagePermissionStatus.then((value) {
+      storagePermissionIsGranted = value.isGranted;
+      if (context.mounted) setState(() {});
+    });
+    super.initState();
+  }
+
   @override
   Widget build(BuildContext context) {
+    final titlePadding = Theme.of(context).listTileTheme.contentPadding!;
+    checkStoragePermission;
     return Scaffold(
       appBar: AppBar(title: Text(AppLocalizations.of(context)!.settings)),
-      body: SizedBox(
+      body: Center(
+        child: SizedBox(
           width: MediaQuery.of(context).size.width * 0.9,
           child: Column(
-          crossAxisAlignment: CrossAxisAlignment.center,
+            crossAxisAlignment: CrossAxisAlignment.start,
             children: [
-            Text(
+              Padding(
+                padding: titlePadding,
+                child: Text(
                   AppLocalizations.of(context)!.appData,
                   style: Theme.of(context).textTheme.titleLarge,
                 ),
-            ElevatedButton(
-              onPressed: () => onActivateJsonImportPressed(),
-              child: Text(AppLocalizations.of(context)!.import),
               ),
-            ElevatedButton(
+              SizedBox(height: tileSpacing),
-              onPressed: () => onActivateJsonExportPressed(),
+              ListTile(
-              child: Text(AppLocalizations.of(context)!.export),
+                title: Text('Grant storage permisson'),
+                subtitle: 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,
+              ),
+              SizedBox(height: tileSpacing),
+              ListTile(
+                title: Text(AppLocalizations.of(context)!.import),
+                subtitle: Text('Import app-data from a json file.'),
+                onTap: () => onActivateJsonImportPressed(),
+                trailing: Icon(Icons.arrow_forward_ios_rounded),
+                enabled: storagePermissionIsGranted,
+              ),
+              SizedBox(height: tileSpacing),
+              ListTile(
+                title: Text(AppLocalizations.of(context)!.export),
+                subtitle: Text(
+                  'Export app-data to a json file in the selected directory.',
+                ),
+                onTap: () => onActivateJsonExportPressed(),
+                trailing: Icon(Icons.arrow_forward_ios_rounded),
+                enabled: storagePermissionIsGranted,
               ),
             ],
           ),
         ),
+      ),
     );
   }
 
   void onActivateJsonExportPressed() async {
-    if (!await checkStoragePermission) return;
+    if (!await PermissionService.storagePermissionStatus.isGranted) return;
-
     Storage.exportToJsonFile().then(showExportInfo);
   }
 
   void onActivateJsonImportPressed() async {
-    if (!await checkStoragePermission) return;
+    if (!await PermissionService.storagePermissionStatus.isGranted) return;
     Storage.importFromJsonFile().then(showImportInfo);
   }
 
-  Future<bool> get checkStoragePermission async {
+  Future<void> get checkStoragePermission async {
-    if (!(await PermissionService.requestStoragePermission).isGranted) {
+    PermissionService.storagePermissionStatus.then((value) {
-      if (mounted) {
+      storagePermissionIsGranted = value.isGranted;
-        Notifying.showErrorSnackbar(
+      if (context.mounted && value.isGranted != storagePermissionIsGranted) {
-          context,
+        setState(() {});
-          AppLocalizations.of(context)!.errorStoragePermisson,
-        );
-        return false;
       }
-    }
+    });
-    return true;
   }
 
   void showExportInfo(bool success) => Notifying.showSnackbar(
@@ -73,7 +107,7 @@ class _SettingsPageState extends State<SettingsPage> {
     text: success
         ? AppLocalizations.of(context)!.exportSuccess
         : AppLocalizations.of(context)!.exportFailed,
-    isError: success,
+    isError: !success,
   );
 
   void showImportInfo(bool success) => Notifying.showSnackbar(
@@ -81,6 +115,6 @@ class _SettingsPageState extends State<SettingsPage> {
     text: success
         ? AppLocalizations.of(context)!.importSuccess
         : AppLocalizations.of(context)!.importFailed,
-    isError: success,
+    isError: !success,
   );
 }

lib/service/json_file_service.dart

@@ -32,7 +32,7 @@ class JsonFileService {
     } catch (e) {
       return false;
     }
-    return false;
+    return true;
   }
 
   static Future<({List<Collection> collections, List<Bookmark> bookmarks})>

lib/service/notifying.dart

@@ -12,7 +12,7 @@ class Notifying {
     ScaffoldMessenger.of(context).hideCurrentSnackBar();
     ScaffoldMessenger.of(context).showSnackBar(
       SnackBar(
-        backgroundColor: Theme.of(context).colorScheme.error,
+        backgroundColor: isError ? Theme.of(context).colorScheme.error : null,
         content: SizedBox(
           height: 30,
           child: Row(
@@ -29,7 +29,7 @@ class Notifying {
                     ScaffoldMessenger.of(context).hideCurrentSnackBar(),
                 icon: Icon(
                   Icons.close_rounded,
-                  color: Theme.of(context).colorScheme.onError,
+                  color: isError ? Theme.of(context).colorScheme.onError : null,
                 ),
               ),
             ],

lib/service/settings_provider.dart

@@ -0,0 +1,20 @@
+import 'package:flutter/material.dart';
+
+import '../model/settings.dart';
+import 'storage.dart';
+
+class SettingsProvider extends ChangeNotifier {
+  SettingsProvider() : _settings = Storage.loadSettings();
+
+  Settings _settings;
+
+  Settings get settings => _settings;
+
+  void setExportDirectoryPath(String path, {bool silent = false}) {
+    _settings = _settings.copyWith(exportDirectoryPath: path);
+    _saveSettings();
+    if (!silent) notifyListeners();
+  }
+
+  void _saveSettings() => Storage.saveSettings(_settings);
+}

lib/service/storage.dart

@@ -4,22 +4,46 @@ import 'package:shared_preferences/shared_preferences.dart';
 
 import '../model/bookmark.dart';
 import '../model/collection.dart';
+import '../model/settings.dart';
 import 'json_file_service.dart';
 
 class Storage {
   static const String _bookmarksKey = 'bookmarks';
   static const String _collectionsKey = 'collections';
   static SharedPreferencesWithCache? _prefsWithCache;
+  static const String _settingsKey = 'settings';
   static const String _statsKey = 'stats';
 
   static Future<void> initialize() async {
     _prefsWithCache = await SharedPreferencesWithCache.create(
       cacheOptions: const SharedPreferencesWithCacheOptions(
-        allowList: <String>{_collectionsKey, _bookmarksKey, _statsKey},
+        allowList: <String>{
+          _collectionsKey,
+          _bookmarksKey,
+          _statsKey,
+          _settingsKey,
+        },
       ),
     );
   }
 
+  static Settings loadSettings() {
+    final jsonString = _prefs.getString(_settingsKey);
+    if (jsonString != null) {
+      final json = jsonDecode(jsonString) as Map<String, dynamic>;
+      return Settings.fromJson(json);
+    } else {
+      final settings = Settings.defaults();
+      saveSettings(settings);
+      return settings;
+    }
+  }
+
+  static Future<void> saveSettings(Settings settings) {
+    final json = jsonEncode(settings.toJson());
+    return _prefs.setString(_settingsKey, json);
+  }
+
   static List<Collection> loadCollections() {
     final jsonString = _prefs.getString(_collectionsKey) ?? '[]';
     final jsonList = jsonDecode(jsonString) as List;
@@ -156,15 +180,6 @@ class Storage {
     await _prefs.setString(_statsKey, jsonEncode(stats));
   }
 
-  static SharedPreferencesWithCache get _prefs {
-    if (_prefsWithCache == null) {
-      throw StateError(
-        'BookmarkStorage not initialized. Call initialize() first.',
-      );
-    }
-    return _prefsWithCache!;
-  }
-
   static Future<bool> exportToJsonFile() => JsonFileService.exportToJson(
     collections: loadCollections(),
     bookmarks: loadBookmarks(),
@@ -180,4 +195,13 @@ class Storage {
     }
     return false;
   }
+
+  static SharedPreferencesWithCache get _prefs {
+    if (_prefsWithCache == null) {
+      throw StateError(
+        'BookmarkStorage not initialized. Call initialize() first.',
+      );
+    }
+    return _prefsWithCache!;
+  }
 }

lib/theme.dart

@@ -22,5 +22,6 @@ ThemeData _baseTheme(ColorScheme scheme) =>
         shape: RoundedRectangleBorder(
           borderRadius: BorderRadiusGeometry.circular(12),
         ),
+        contentPadding: EdgeInsetsDirectional.only(start: 16.0, end: 24.0),
       ),
     );