import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Split Screen App',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: SplitScreen(),
    );
  }
}

class SplitScreen extends StatefulWidget {
  @override
  _SplitScreenState createState() => _SplitScreenState();
}

class _SplitScreenState extends State<SplitScreen> {
  int _selectedIndex = 0;

  static const List<Widget> _views = [
    Center(child: Text('View 1')),
    Center(child: Text('View 2')),
    Center(child: Text('View 3')),
  ];

  void _onItemTapped(int index) {
    setState(() {
      _selectedIndex = index;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: [
          SliverAppBar(
            title: Text('Split Screen'),
            floating: true,
            actions: [
              IconButton(
                icon: Icon(Icons.emoji_emotions),
                onPressed: () {
                  _onItemTapped(0);
                },
              ),
              IconButton(
                icon: Icon(Icons.emoji_events),
                onPressed: () {
                  _onItemTapped(1);
                },
              ),
              IconButton(
                icon: Icon(Icons.emoji_flags),
                onPressed: () {
                  _onItemTapped(2);
                },
              ),
            ],
          ),
          SliverFillRemaining(
            child: AnimatedSwitcher(
              duration: Duration(milliseconds: 500),
              child: _views[_selectedIndex],
            ),
          ),
        ],
      ),
    );
  }
}