created first pages and bottom bar

lib/homepage.dart

+// ignore_for_file: prefer_const_constructors, prefer_const_literals_to_create_immutables
+
+import 'package:ambient/moodpage.dart';
+import 'package:flutter/material.dart';
+import 'dart:math' as math;
+import 'package:google_nav_bar/google_nav_bar.dart';
+
+class HomePage extends StatefulWidget {
+  const HomePage({Key? key}) : super(key: key);
+
+  @override
+  State<StatefulWidget> createState() => _HomePageState();
+}
+
+class _HomePageState extends State<HomePage> {
+  static Color color = Colors.black;
+
+  @override
+  Widget build(BuildContext context) {
+    color =
+        Color((math.Random().nextDouble() * 0xFFFFFF).toInt()).withOpacity(1.0);
+
+    return Scaffold(
+      bottomNavigationBar: Container(
+        color: color,
+        child: Padding(
+          padding: EdgeInsets.symmetric(horizontal: 15.0, vertical: 20),
+          child: GNav(
+            backgroundColor: color,
+            color: Colors.white,
+            activeColor: Colors.white,
+            tabBackgroundColor: Colors.grey,
+            gap: 8,
+            padding: EdgeInsets.all(16),
+            tabs: [
+              GButton(
+                icon: Icons.mood,
+                text: "Moods",
+              ),
+              GButton(
+                icon: Icons.home,
+                text: "Home",
+              ),
+              GButton(
+                icon: Icons.search,
+                text: "Suchen",
+              )
+            ],
+            onTabChange: (index) {
+              if (index == 0) {
+                Navigator.push(context,
+                    MaterialPageRoute(builder: (context) => MoodPage()));
+              }
+            },
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/main.dart

 import 'package:flutter/material.dart';
+import 'homepage.dart';
 
 void main() {
   runApp(const MyApp());
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+  const MyApp({Key? key}) : super(key: key);
 
-  // This widget is the root of your application.
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Ambient',
-      theme: ThemeData(
-        // This is the theme of your application.
-        //
-        // Try running your application with "flutter run". You'll see the
-        // application has a blue toolbar. Then, without quitting the app, try
-        // changing the primarySwatch below to Colors.green and then invoke
-        // "hot reload" (press "r" in the console where you ran "flutter run",
-        // or simply save your changes to "hot reload" in a Flutter IDE).
-        // Notice that the counter didn't reset back to zero; the application
-        // is not restarted.
-        primarySwatch: Colors.blue,
-      ),
-      home: const MyHomePage(title: 'Ambient Home Page'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
-
-  final String title;
-
-  @override
-  State<MyHomePage> createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
-    return Scaffold(
-      appBar: AppBar(
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
-        title: Text(widget.title),
-      ),
-      body: Center(
-        // Center is a layout widget. It takes a single child and positions it
-        // in the middle of the parent.
-        child: Column(
-          // Column is also a layout widget. It takes a list of children and
-          // arranges them vertically. By default, it sizes itself to fit its
-          // children horizontally, and tries to be as tall as its parent.
-          //
-          // Invoke "debug painting" (press "p" in the console, choose the
-          // "Toggle Debug Paint" action from the Flutter Inspector in Android
-          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
-          // to see the wireframe for each widget.
-          //
-          // Column has various properties to control how it sizes itself and
-          // how it positions its children. Here we use mainAxisAlignment to
-          // center the children vertically; the main axis here is the vertical
-          // axis because Columns are vertical (the cross axis would be
-          // horizontal).
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            const Text(
-              'You have pushed the button this many times:',
-            ),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headline4,
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
-      ), // This trailing comma makes auto-formatting nicer for build methods.
+    return const MaterialApp(
+      debugShowCheckedModeBanner: false,
+      home: HomePage(),
     );
   }
 }

lib/moodpage.dart

+import 'package:flutter/material.dart';
+
+class MoodPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("MoodPage"),
+      ),
+    );
+  }
+}

lib/searchpage.dart

+import 'package:flutter/material.dart';
+
+class SearchPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("Searchpage"),
+      ),
+    );
+  }
+}

pubspec.lock

@@ -67,6 +67,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  google_nav_bar:
+    dependency: "direct main"
+    description:
+      name: google_nav_bar
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "5.0.6"
   lints:
     dependency: transitive
     description:

pubspec.yaml

@@ -36,6 +36,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
+  google_nav_bar: ^5.0.6
 
 dev_dependencies:
   flutter_test: