Constant Dark Theme

lib/app_settings.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:witl/theme_manager.dart';
 
 class Settings extends StatelessWidget {
   const Settings({super.key});
@@ -7,8 +8,14 @@ class Settings extends StatelessWidget {
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
-        title: const Text("Settings Screen"),
+        title: const Text("Settings"),
       ),
+
+      body: ListView(
+        children: [
+          
+        ],
+      )
     );
   }
 }

lib/main.dart

@@ -15,8 +15,23 @@ class MyApp extends StatelessWidget {
       title: "Entry Point",
       theme: ThemeData(
         primarySwatch: Colors.blue,
+        primaryColor: Colors.white,
+        brightness: Brightness.light,
+        dividerColor: Colors.white54,
+        scaffoldBackgroundColor: Colors.white,
       ),
 
+      darkTheme: ThemeData(
+        primarySwatch: Colors.blue,
+        primaryColor: Colors.black,
+        brightness: Brightness.dark,
+        dividerColor: Colors.black12,
+        scaffoldBackgroundColor: Color(0xFF131313),
+
+      ),
+
+      themeMode: ThemeMode.system,
+
       // Navigashun with Routes
       // Base "Home" Route
       initialRoute: '/',

lib/storage_manager.dart

@@ -0,0 +1,27 @@
+import 'package:shared_preferences/shared_preferences.dart';
+
+class StorageManager {
+  static void saveData(String key, dynamic value) async {
+    final prefs = await SharedPreferences.getInstance();
+    if (value is int) {
+      prefs.setInt(key, value);
+    } else if (value is String) {
+      prefs.setString(key, value);
+    } else if (value is bool) {
+      prefs.setBool(key, value);
+    } else {
+      throw("Invalid Type (Shared Preference Error)");
+    }
+  }
+
+  static Future<dynamic> readData(String key) async {
+    final prefs = await SharedPreferences.getInstance();
+    dynamic obj = prefs.get(key);
+    return obj;
+  }
+
+  static Future<bool> deleteData(String key) async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.remove(key);
+  }
+}

lib/theme_manager.dart

@@ -0,0 +1,45 @@
+import 'package:flutter/material.dart';
+import 'package:witl/storage_manager.dart';
+
+class ThemeNotifier with ChangeNotifier {
+  final darkTheme = ThemeData(
+    primaryColor: Colors.black,
+    brightness: Brightness.dark,
+    dividerColor: Colors.black12, colorScheme: ColorScheme.fromSwatch(primarySwatch: Colors.grey).copyWith(background: const Color(0xFF212121)),
+  );
+
+  final lightTheme = ThemeData(
+    primaryColor: Colors.white,
+    brightness: Brightness.light,
+    dividerColor: Colors.white54, colorScheme: ColorScheme.fromSwatch(primarySwatch: Colors.grey).copyWith(background: const Color(0xFFE5E5E5)),
+  );
+
+  late ThemeData _themeData;
+  ThemeData getTheme() => _themeData;
+
+  ThemeNotifier() {
+    StorageManager.readData('themeMode').then((value) {
+      'value read from storage: ' + value.toString();
+      var themeMode = value ?? 'light';
+      if (themeMode == 'light') {
+        _themeData = lightTheme;
+      } else {
+        'setting dark theme';
+        _themeData = darkTheme;
+      }
+      notifyListeners();
+    });
+  }
+
+  void setDarkMode() async {
+    _themeData = darkTheme;
+    StorageManager.saveData('themeMode', 'dark');
+    notifyListeners();
+  }
+
+  void setLightMode() async {
+    _themeData = lightTheme;
+    StorageManager.saveData('themeMode', 'light');
+    notifyListeners();
+  }
+}