refactor: split app wrapper from focused example code (complex apps)

Convert the final 12 multi-screen apps to the validated pattern:
lib/main.dart keeps only the MaterialApp bootstrap (plus firebase init where
that is genuine bootstrap), and a new lib/example.dart holds the entry screen
and focused example code, importing existing supporting files. firebase_crash
keeps its runZonedGuarded bootstrap in main.dart and extracts only CrashApp.

Apps: bmi_calculator, covid19_mobile_app, expense_planner,
firebase_crash_reporting, firebase_google_authentication, lunch_app,
navigation_drawer, news_memes_app, save_data_locally_with_sqlite,
todo_list_using_provider, unit_testing, using_firebase_db

bmi_calculator/lib/example.dart

@@ -0,0 +1,12 @@
+import 'package:bmi_calculator/calculator/calculator_page.dart';
+import 'package:flutter/material.dart';
+
+// Example: BMI calculator entry screen.
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return CalculatorPage(title: 'BMI CALCULATOR');
+  }
+}

bmi_calculator/lib/main.dart

@@ -1,7 +1,8 @@
-import 'package:bmi_calculator/calculator/calculator_page.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
+import 'example.dart';
+
 void main() {
   WidgetsFlutterBinding.ensureInitialized();
 
@@ -20,7 +21,7 @@ class MyApp extends StatelessWidget {
   Widget build(BuildContext context) {
     return MaterialApp(
       title: 'BMI Calculator',
-      home: CalculatorPage(title: 'BMI CALCULATOR'),
+      home: const Example(),
     );
   }
 }

covid19_mobile_app/lib/example.dart

@@ -0,0 +1,12 @@
+// Example: World Wide COVID-19 cases with daily charts
+import 'package:flutter/material.dart';
+import 'screens/home.dart';
+
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Home();
+  }
+}

covid19_mobile_app/lib/main.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'screens/home.dart';
+import 'example.dart';
 
 void main() => runApp(MyApp());
 
@@ -18,7 +18,7 @@ class MyApp extends StatelessWidget {
         ).copyWith(secondary: Color(0xfff4796b)),
         brightness: Brightness.dark,
       ),
-      home: Home(),
+      home: const Example(),
     );
   }
 }

expense_planner/lib/example.dart

@@ -0,0 +1,93 @@
+// Example: Track personal expenses with a chart and a list of transactions.
+
+import 'package:flutter/material.dart';
+
+import './models/transaction.dart';
+import './widgets/chart.dart';
+import './widgets/new_transaction.dart';
+import './widgets/transaction_list.dart';
+
+class Example extends StatefulWidget {
+  const Example({super.key});
+
+  @override
+  _ExampleState createState() => _ExampleState();
+}
+
+class _ExampleState extends State<Example> {
+  final List<Transaction> _userTransactions = [];
+
+  List<Transaction> get _recentTransactions {
+    return _userTransactions.where((tx) {
+      return tx.date.isAfter(
+        DateTime.now().subtract(
+          Duration(days: 7),
+        ),
+      );
+    }).toList();
+  }
+
+  void _addNewTransaction(
+      String txTitle, double txAmount, DateTime chosenDate) {
+    final newTx = Transaction(
+      title: txTitle,
+      amount: txAmount,
+      date: chosenDate,
+      id: DateTime.now().toString(),
+    );
+
+    setState(() {
+      _userTransactions.add(newTx);
+    });
+  }
+
+  void _startAddNewTransaction(BuildContext ctx) {
+    showModalBottomSheet(
+      context: ctx,
+      builder: (_) {
+        return GestureDetector(
+          onTap: () {},
+          behavior: HitTestBehavior.opaque,
+          child: NewTransaction(_addNewTransaction),
+        );
+      },
+    );
+  }
+
+  void _deleteTransaction(String id) {
+    setState(() {
+      _userTransactions.removeWhere((tx) => tx.id == id);
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(
+          'Personal Expenses',
+        ),
+        actions: <Widget>[
+          IconButton(
+            icon: Icon(Icons.add),
+            onPressed: () => _startAddNewTransaction(context),
+          ),
+        ],
+      ),
+      body: SingleChildScrollView(
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: <Widget>[
+            Chart(_recentTransactions),
+            TransactionList(_userTransactions, _deleteTransaction),
+          ],
+        ),
+      ),
+      floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
+      floatingActionButton: FloatingActionButton(
+        child: Icon(Icons.add),
+        onPressed: () => _startAddNewTransaction(context),
+      ),
+    );
+  }
+}

expense_planner/lib/main.dart

@@ -1,11 +1,8 @@
 import 'package:flutter/material.dart';
 
-import './widgets/new_transaction.dart';
-import './widgets/transaction_list.dart';
-import './widgets/chart.dart';
-import './models/transaction.dart';
+import 'example.dart';
 
-void main() => runApp(MyApp());
+void main() => runApp(const MyApp());
 
 class MyApp extends StatelessWidget {
   const MyApp({super.key});
@@ -34,92 +31,7 @@ class MyApp extends StatelessWidget {
               fontWeight: FontWeight.bold,
             ),
           )),
-      home: MyHomePage(),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key});
-
-  @override
-  _MyHomePageState createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  final List<Transaction> _userTransactions = [];
-
-  List<Transaction> get _recentTransactions {
-    return _userTransactions.where((tx) {
-      return tx.date.isAfter(
-        DateTime.now().subtract(
-          Duration(days: 7),
-        ),
-      );
-    }).toList();
-  }
-
-  void _addNewTransaction(
-      String txTitle, double txAmount, DateTime chosenDate) {
-    final newTx = Transaction(
-      title: txTitle,
-      amount: txAmount,
-      date: chosenDate,
-      id: DateTime.now().toString(),
-    );
-
-    setState(() {
-      _userTransactions.add(newTx);
-    });
-  }
-
-  void _startAddNewTransaction(BuildContext ctx) {
-    showModalBottomSheet(
-      context: ctx,
-      builder: (_) {
-        return GestureDetector(
-          onTap: () {},
-          behavior: HitTestBehavior.opaque,
-          child: NewTransaction(_addNewTransaction),
-        );
-      },
-    );
-  }
-
-  void _deleteTransaction(String id) {
-    setState(() {
-      _userTransactions.removeWhere((tx) => tx.id == id);
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: Text(
-          'Personal Expenses',
-        ),
-        actions: <Widget>[
-          IconButton(
-            icon: Icon(Icons.add),
-            onPressed: () => _startAddNewTransaction(context),
-          ),
-        ],
-      ),
-      body: SingleChildScrollView(
-        child: Column(
-          crossAxisAlignment: CrossAxisAlignment.stretch,
-          children: <Widget>[
-            Chart(_recentTransactions),
-            TransactionList(_userTransactions, _deleteTransaction),
-          ],
-        ),
-      ),
-      floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
-      floatingActionButton: FloatingActionButton(
-        child: Icon(Icons.add),
-        onPressed: () => _startAddNewTransaction(context),
-      ),
+      home: const Example(),
     );
   }
 }

firebase_crash_reporting/lib/example.dart

@@ -0,0 +1,31 @@
+import 'package:firebase_crashlytics/firebase_crashlytics.dart';
+import 'package:flutter/material.dart';
+
+// Example: Two buttons to test Crashlytics custom logging and crash reporting.
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          ElevatedButton(
+              onPressed: () {
+                //custom Crashlytics log message
+                FirebaseCrashlytics.instance.log("It's a bug");
+              },
+              child: Text("Custom Log")),
+          const SizedBox(height: 10),
+          ElevatedButton(
+            child: Text('Crash the app'),
+            onPressed: () {
+              FirebaseCrashlytics.instance.crash();
+            },
+          ),
+        ],
+      ),
+    );
+  }
+}

firebase_crash_reporting/lib/main.dart

@@ -4,6 +4,8 @@ import 'package:firebase_core/firebase_core.dart';
 import 'package:firebase_crashlytics/firebase_crashlytics.dart';
 import 'package:flutter/material.dart';
 
+import 'example.dart';
+
 void main() {
   WidgetsFlutterBinding.ensureInitialized();
   runZonedGuarded(() {
@@ -17,12 +19,12 @@ void main() {
 class App extends StatelessWidget {
   const App({super.key});
 
-
   //initialise firebase and crashlytics
   Future<void> _initializeFirebase() async {
     await Firebase.initializeApp();
     await FirebaseCrashlytics.instance.setCrashlyticsCollectionEnabled(true);
   }
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -40,7 +42,7 @@ class App extends StatelessWidget {
             }
             //firebase and crashlytics initialise complete
             if (snapshot.connectionState == ConnectionState.done) {
-              return CrashApp();
+              return const Example();
             }
             return Center(
               child: Column(
@@ -56,31 +58,3 @@ class App extends StatelessWidget {
     );
   }
 }
-
-class CrashApp extends StatelessWidget {
-  const CrashApp({super.key});
-
-  @override
-  Widget build(BuildContext context) {
-    return Center(
-      child: Column(
-        mainAxisAlignment: MainAxisAlignment.center,
-        children: [
-          ElevatedButton(
-              onPressed: () {
-                //custom Crashlytics log message
-                FirebaseCrashlytics.instance.log("It's a bug");
-              },
-              child: Text("Custom Log")),
-          const SizedBox(height: 10),
-          ElevatedButton(
-            child: Text('Crash the app'),
-            onPressed: () {
-              FirebaseCrashlytics.instance.crash();
-            },
-          ),
-        ],
-      ),
-    );
-  }
-}

firebase_google_authentication/lib/example.dart

@@ -0,0 +1,13 @@
+// Example: Google sign-in flow with login, signup, and an authenticated info page.
+
+import 'package:firebase_google_authentication/Screens/HomePage.dart';
+import 'package:flutter/material.dart';
+
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const HomePage();
+  }
+}

firebase_google_authentication/lib/main.dart

@@ -1,13 +1,13 @@
 import 'package:firebase_core/firebase_core.dart';
-import 'package:firebase_google_authentication/Screens/HomePage.dart';
 import 'package:firebase_google_authentication/Services/google_auth.dart';
+import 'package:firebase_google_authentication/example.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
-void main() async{
+void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   await Firebase.initializeApp();
-  runApp(MyApp());
+  runApp(const MyApp());
 }
 
 class MyApp extends StatelessWidget {
@@ -19,7 +19,7 @@ class MyApp extends StatelessWidget {
       create: (context) => GoogleSignInProvider(),
       child: MaterialApp(
         debugShowCheckedModeBanner: false,
-        home: HomePage(),
+        home: const Example(),
       ),
     );
   }

lunch_app/lib/example.dart

@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+import 'package:lunch_app/views/prototype/home.dart';
+
+// Example: Lunch app entry screen with category, option, and food listing.
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const Home();
+  }
+}

lunch_app/lib/main.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
 
-import 'views/prototype/home.dart';
+import 'example.dart';
 
 void main() => runApp(LunchApp());
 
@@ -23,7 +23,7 @@ class LunchApp extends StatelessWidget {
           ),
         ),
       ),
-      home: Home(),
+      home: const Example(),
     );
   }
 }

navigation_drawer/lib/example.dart

@@ -0,0 +1,13 @@
+// Example: A home screen with a navigation drawer to switch between settings and account screens.
+
+import 'package:flutter/material.dart';
+import 'package:navigation_drawer/screens/home.dart';
+
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const HomeScreen();
+  }
+}

navigation_drawer/lib/main.dart

@@ -1,16 +1,25 @@
 import 'package:flutter/material.dart';
+import 'package:navigation_drawer/example.dart';
 import 'package:navigation_drawer/screens/account.dart';
-import 'package:navigation_drawer/screens/home.dart';
 import 'package:navigation_drawer/screens/settings.dart';
 
 void main() {
-  runApp(MaterialApp(
-    debugShowCheckedModeBanner: false,
-    home: HomeScreen(), // route for home is '/' implicitly
-    routes: <String, WidgetBuilder>{
-      // define the routes
-      SettingsScreen.routeName: (BuildContext context) => SettingsScreen(),
-      AccountScreen.routeName: (BuildContext context) => AccountScreen(),
-    },
-  ));
+  runApp(const MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      debugShowCheckedModeBanner: false,
+      home: const Example(), // route for home is '/' implicitly
+      routes: <String, WidgetBuilder>{
+        // define the routes
+        SettingsScreen.routeName: (BuildContext context) => SettingsScreen(),
+        AccountScreen.routeName: (BuildContext context) => AccountScreen(),
+      },
+    );
+  }
 }

news_memes_app/lib/example.dart

@@ -0,0 +1,12 @@
+// Example: Home page with news and memes navigation
+import 'package:flutter/material.dart';
+import 'package:news_memes_app/Screens/HomePage.dart';
+
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const HomePage();
+  }
+}

news_memes_app/lib/main.dart

@@ -1,8 +1,17 @@
 import 'package:flutter/material.dart';
-import 'package:news_memes_app/Screens/HomePage.dart';
+import 'example.dart';
 
 void main() {
-  runApp(MaterialApp(
-    home: HomePage(),
-  ));
+  runApp(MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: const Example(),
+    );
+  }
 }

save_data_locally_with_sqlite/lib/example.dart

@@ -0,0 +1,12 @@
+// Example: Save data locally using sqlite
+import 'package:flutter/material.dart';
+import 'package:save_data_locally_with_sqlite/screens/homescreen/homescreen.dart';
+
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const HomeScreen();
+  }
+}

save_data_locally_with_sqlite/lib/main.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:save_data_locally_with_sqlite/screens/homescreen/homescreen.dart';
+import 'example.dart';
 
 void main() {
   runApp(MyApp());
@@ -16,7 +16,7 @@ class MyApp extends StatelessWidget {
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: HomeScreen(),
+      home: const Example(),
     );
   }
 }

todo_list_using_provider/lib/example.dart

@@ -0,0 +1,18 @@
+// Example: Todo list using provider
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import 'notifiers/todo_list.dart';
+import 'views/home.dart';
+
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return ChangeNotifierProvider<TodoList>(
+      create: (context) => TodoList(),
+      child: const MyHomePage(title: 'Flutter Demo Home Page'),
+    );
+  }
+}

todo_list_using_provider/lib/main.dart

@@ -1,8 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:provider/provider.dart';
-
-import 'notifiers/todo_list.dart';
-import 'views/home.dart';
+import 'example.dart';
 
 void main() {
   runApp(MyApp());
@@ -20,10 +17,7 @@ class MyApp extends StatelessWidget {
         primarySwatch: Colors.blue,
         visualDensity: VisualDensity.adaptivePlatformDensity,
       ),
-      home: ChangeNotifierProvider<TodoList>(
-        create: (context) => TodoList(),
-        child: MyHomePage(title: 'Flutter Demo Home Page'),
-      ),
+      home: const Example(),
     );
   }
-}
+}

unit_testing/lib/example.dart

@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+import 'package:unit_testing/screens/sign_in_screen.dart';
+
+// Example: Sign-in entry screen with email and password validation.
+class Example extends StatelessWidget {
+  const Example({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const SignInScreen();
+  }
+}

unit_testing/lib/main.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 import 'package:unit_testing/screens/home_screen.dart';
 import 'package:unit_testing/screens/sign_in_screen.dart';
 
+import 'example.dart';
+
 void main() => runApp(MyApp());
 
 class MyApp extends StatelessWidget {
@@ -13,6 +15,7 @@ class MyApp extends StatelessWidget {
       debugShowCheckedModeBanner: false,
       title: 'Material App',
       initialRoute: "/",
+      home: const Example(),
       routes: {
         "/": (context) => SignInScreen(),
         "/homeScreen": (context) => HomeScreen(),

using_firebase_db/lib/example.dart

@@ -0,0 +1,128 @@
+// Example: Store and manage notes in a Firebase Realtime Database.
+
+import 'dart:async';
+import 'package:firebase_database/firebase_database.dart';
+
+import 'package:flutter/material.dart';
+
+class Note {
+  late String id;
+  late String content;
+  late String createdOn;
+
+  Note(this.content) {
+    createdOn = DateTime.now().toString();
+  }
+}
+
+class Example extends StatefulWidget {
+  const Example({super.key});
+
+  @override
+  _ExampleState createState() => _ExampleState();
+}
+
+class _ExampleState extends State<Example> {
+  final notesRef = FirebaseDatabase.instance.ref().child('notes');
+  final inputController = TextEditingController();
+  late StreamSubscription<DatabaseEvent> _noteAddedStream;
+  List<Note> items = [];
+
+  @override
+  void initState() {
+    super.initState();
+
+    _noteAddedStream =
+        notesRef.orderByChild("created_on").onChildAdded.listen(_onNoteAdded);
+  }
+
+  // Creates a new child under notes in the database
+  void _addNote() {
+    var note = Note(inputController.text);
+    inputController.text = "";
+    if (note.content.isNotEmpty) {
+      notesRef.push().set({
+        'content': note.content,
+        'created_on': note.createdOn,
+      });
+    }
+  }
+
+  // Fired whenever the database sees a new child under the notes
+  // database reference
+  void _onNoteAdded(DatabaseEvent event) {
+    setState(() {
+      final value = event.snapshot.value as Map;
+      var note = Note(value["content"] as String);
+      note.id = event.snapshot.key!;
+      note.createdOn = value["created_on"] as String;
+      items.add(note);
+    });
+  }
+
+  @override
+  void dispose() {
+    _noteAddedStream.cancel();
+    super.dispose();
+  }
+
+  // The note has to be cleared from the database and the local list
+  void _deleteNote(int position) {
+    String id = items[position].id;
+    notesRef.child(id).remove().then((_) {
+      setState(() {
+        items.removeAt(position);
+      });
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("Using Firebase DB"),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            Container(
+              padding: EdgeInsets.all(15.0),
+              child: TextField(
+                style:
+                    TextStyle(fontSize: 24.0, height: 2.0, color: Colors.black),
+                decoration: InputDecoration(
+                    border: InputBorder.none, hintText: 'Add a note'),
+                controller: inputController,
+              ),
+            ),
+            Expanded(
+              child: SizedBox(
+                height: 200.0,
+                child: ListView.builder(
+                    itemCount: items.length,
+                    padding: const EdgeInsets.all(10.0),
+                    itemBuilder: (context, position) {
+                      return Card(
+                        child: ListTile(
+                          leading: Icon(Icons.note),
+                          title: Text(items[position].content),
+                          onLongPress: () {
+                            _deleteNote(position);
+                          },
+                        ),
+                      );
+                    }),
+              ),
+            ),
+          ],
+        ),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: _addNote,
+        tooltip: 'Add Note',
+        child: Icon(Icons.add),
+      ),
+    );
+  }
+}

using_firebase_db/lib/main.dart

@@ -1,19 +1,8 @@
-import 'dart:async';
-import 'package:firebase_database/firebase_database.dart';
-
 import 'package:flutter/material.dart';
 
-class Note {
-  late String id;
-  late String content;
-  late String createdOn;
+import 'example.dart';
 
-  Note(this.content) {
-    createdOn = DateTime.now().toString();
-  }
-}
-
-void main() => runApp(MyApp());
+void main() => runApp(const MyApp());
 
 class MyApp extends StatelessWidget {
   const MyApp({super.key});
@@ -25,120 +14,7 @@ class MyApp extends StatelessWidget {
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: MyHomePage(title: 'Firebase demo'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  final String title;
-  @override
-  _MyHomePageState createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  final notesRef = FirebaseDatabase.instance.ref().child('notes');
-  final inputController = TextEditingController();
-  late StreamSubscription<DatabaseEvent> _noteAddedStream;
-  List<Note> items = [];
-
-  @override
-  void initState() {
-    super.initState();
-
-    _noteAddedStream =
-        notesRef.orderByChild("created_on").onChildAdded.listen(_onNoteAdded);
-  }
-
-  // Creates a new child under notes in the database
-  void _addNote() {
-    var note = Note(inputController.text);
-    inputController.text = "";
-    if (note.content.isNotEmpty) {
-      notesRef.push().set({
-        'content': note.content,
-        'created_on': note.createdOn,
-      });
-    }
-  }
-
-  // Fired whenever the database sees a new child under the notes
-  // database reference
-  void _onNoteAdded(DatabaseEvent event) {
-    setState(() {
-      final value = event.snapshot.value as Map;
-      var note = Note(value["content"] as String);
-      note.id = event.snapshot.key!;
-      note.createdOn = value["created_on"] as String;
-      items.add(note);
-    });
-  }
-
-  @override
-  void dispose() {
-    _noteAddedStream.cancel();
-    super.dispose();
-  }
-
-  // The note has to be cleared from the database and the local list
-  void _deleteNote(int position) {
-    String id = items[position].id;
-    notesRef.child(id).remove().then((_) {
-      setState(() {
-        items.removeAt(position);
-      });
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: Text("Using Firebase DB"),
-      ),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            Container(
-              padding: EdgeInsets.all(15.0),
-              child: TextField(
-                style:
-                    TextStyle(fontSize: 24.0, height: 2.0, color: Colors.black),
-                decoration: InputDecoration(
-                    border: InputBorder.none, hintText: 'Add a note'),
-                controller: inputController,
-              ),
-            ),
-            Expanded(
-              child: SizedBox(
-                height: 200.0,
-                child: ListView.builder(
-                    itemCount: items.length,
-                    padding: const EdgeInsets.all(10.0),
-                    itemBuilder: (context, position) {
-                      return Card(
-                        child: ListTile(
-                          leading: Icon(Icons.note),
-                          title: Text(items[position].content),
-                          onLongPress: () {
-                            _deleteNote(position);
-                          },
-                        ),
-                      );
-                    }),
-              ),
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _addNote,
-        tooltip: 'Add Note',
-        child: Icon(Icons.add),
-      ),
+      home: const Example(),
     );
   }
 }