import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(MaterialApp(
    title: 'Named Routes Demo',
    // Start the app with the "/" named route. In this case, the app starts
    // on the FirstScreen widget.
    initialRoute: '/',
    routes: {
      // When navigating to the "/" route, build the FirstScreen widget.
      '/': (context) => FirstScreen(),
      // When navigating to the "/second" route, build the SecondScreen widget.
      '/second': (context) => SecondScreen(),
    },
  ));
}

class FirstScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final systemUiOverlayStyle = const SystemUiOverlayStyle(
      statusBarColor: Colors.transparent,
      statusBarIconBrightness: Brightness.dark,
    );

    return AnnotatedRegion<SystemUiOverlayStyle>(
      value: systemUiOverlayStyle,
      child: Container(
        color: Colors.white,
        child: Center(
          child: RaisedButton(
            child: Text('Launch screen'),
            onPressed: () {
              // Navigate to the second screen using a named route.
              Navigator.pushNamed(context, '/second');
            },
          ),
        ),
      ),
    );
  }
}

class SecondScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        brightness: Brightness.dark,
        backgroundColor: Colors.black,
        title: Text("Second Screen"),
      ),
      body: Center(
        child: RaisedButton(
          onPressed: () {
            // Navigate back to the first screen by popping the current route
            // off the stack.
            Navigator.pop(context);
          },
          child: Text('Go back!'),
        ),
      ),
    );
  }
}