Add user store

lib/app.dart

@@ -1,8 +1,10 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
 import 'package:thesis_shop/route_key.dart';
 import 'package:thesis_shop/screens/cart/cart_screen.dart';
 import 'package:thesis_shop/screens/product_list/product_list_screen.dart';
 import 'package:thesis_shop/service/product_service.dart';
+import 'package:thesis_shop/store/user_store.dart';
 import 'package:thesis_shop/utils/map_keys_extension.dart';
 
 class ThesisShopApp extends StatelessWidget {
@@ -12,18 +14,23 @@ class ThesisShopApp extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Thesis Shop',
-      theme: ThemeData(primarySwatch: Colors.red),
-      darkTheme: ThemeData(
-        primarySwatch: Colors.red,
-        brightness: Brightness.dark,
+    return MultiProvider(
+      providers: [
+        ChangeNotifierProvider(create: (context) => UserStore()),
+      ],
+      child: MaterialApp(
+        title: 'Thesis Shop',
+        theme: ThemeData(primarySwatch: Colors.red),
+        darkTheme: ThemeData(
+          primarySwatch: Colors.red,
+          brightness: Brightness.dark,
+        ),
+        routes: {
+          RouteKey.products: (context) => const ProductListScreen(),
+          RouteKey.cart: (context) => const CartScreen(),
+        }.mapKeys((key) => key.name),
+        initialRoute: 'products',
       ),
-      routes: {
-        RouteKey.products: (context) => const ProductListScreen(),
-        RouteKey.cart: (context) => const CartScreen(),
-      }.mapKeys((key) => key.name),
-      initialRoute: 'products',
     );
   }
 }

lib/screens/cart/cart_screen.dart

@@ -20,7 +20,7 @@ class CartScreen extends StatelessWidget {
     return Scaffold(
       appBar: AppBar(
         title: const Text('Warenkorb'),
-        actions: [UserSwitch(isOn: true, onChanged: (_) {})],
+        actions: const [UserSwitch()],
       ),
       body: Column(
         mainAxisSize: MainAxisSize.max,

lib/screens/product_list/product_list_screen.dart

@@ -21,7 +21,7 @@ class ProductListScreen extends StatelessWidget {
     return Scaffold(
       appBar: AppBar(
         title: const Text('Thesis Shop'),
-        actions: [UserSwitch(isOn: true, onChanged: (_) {})],
+        actions: const [UserSwitch()],
       ),
       body: const CartButtonOverlay(
         child: ProductList(products: products),

lib/store/user_store.dart

@@ -0,0 +1,11 @@
+import 'package:flutter/foundation.dart';
+
+class UserStore extends ChangeNotifier {
+  bool _isSignedIn = false;
+  bool get isSignedIn => _isSignedIn;
+
+  void changeSignIn(bool newValue) {
+    _isSignedIn = newValue;
+    notifyListeners();
+  }
+}

lib/widgets/user_switch.dart

@@ -1,24 +1,22 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
 import 'package:thesis_shop/benchmark_counter.dart';
+import 'package:thesis_shop/store/user_store.dart';
 
 class UserSwitch extends StatelessWidget {
-  final bool isOn;
-  final ValueChanged<bool> onChanged;
-  const UserSwitch({
-    required this.isOn,
-    required this.onChanged,
-  }) : super(key: const Key('user_switch'));
+  const UserSwitch() : super(key: const Key('user_switch'));
 
   @override
   Widget build(BuildContext context) {
+    final userStore = context.watch<UserStore>();
     BenchmarkCounters.userSwitch++;
     return Row(
       mainAxisSize: MainAxisSize.min,
       children: [
         const Icon(Icons.account_circle),
         Switch(
-          value: isOn,
-          onChanged: onChanged,
+          value: userStore.isSignedIn,
+          onChanged: userStore.changeSignIn,
           activeColor: Colors.green,
         )
       ],