main.dart

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


// final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
Stream<int> stream;

StreamController<int> myStreamController = StreamController.broadcast();

void main() {
  MyClass myClass = MyClass();

  WidgetsFlutterBinding.ensureInitialized();
  SystemChrome.setPreferredOrientations([DeviceOrientation.landscapeLeft])
      .then((_) {
    runApp(new MyApp());
  });
}


class MyClass {
  MyClass() {
    stream = Stream<int>.periodic(Duration(seconds: 1), (t) => t + 1).take(1);
    myStreamController.addStream(stream).then(
      (done) {
      Future.delayed(Duration(seconds: 1), () { // wait 2 seconds before Showing HomePage
            myStreamController.addStream( Stream.value(42) ); 

            // navigatorKey.currentState.pushNamed("/home");            
           // Navigator.push(context, route)  // But we do not have context in this class!!

          });
      }
    );
    // stream.pipe(myStreamController.sink);

  }
}

class ScaleRotateRoute extends PageRouteBuilder {
  final Widget page;
  ScaleRotateRoute({this.page})
      : super(
          pageBuilder: (
            BuildContext context,
            Animation<double> animation,
            Animation<double> secondaryAnimation,
          ) =>
              page,
          transitionDuration: Duration(seconds: 1),
          transitionsBuilder: (
            BuildContext context,
            Animation<double> animation,
            Animation<double> secondaryAnimation,
            Widget child,
          ) =>
              ScaleTransition(
                scale: Tween<double>(
                  begin: 0.0,
                  end: 1.0,
                ).animate(
                  CurvedAnimation(
                    parent: animation,
                    curve: Curves.fastOutSlowIn,
                  ),
                ),
                child: RotationTransition(
                  turns: Tween<double>(
                    begin: 0.0,
                    end: 1.0,
                  ).animate(
                    CurvedAnimation(
                      parent: animation,
                      curve: Curves.linear,
                    ),
                  ),
                  child: child,
                ),
              ),
        );
}


class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(title: "Hello", 
    routes: 
      {
        '/': (context) => SplashScreen(),
        '/home': (context) => HomePage(),
      },
      // navigatorKey: navigatorKey, 
    );

  }
}

class HomePage extends StatelessWidget {

  Bloc _bloc = Bloc();

  @override
  Widget build(BuildContext context)
  {
    return Scaffold(
      appBar: AppBar(),
      body: Container(
        child: 
        StreamBuilder(
          stream: _bloc.counter,
          initialData: 0,
          builder: (BuildContext context, AsyncSnapshot<int> _snapshot)
          {
            return Column(
              children: <Widget>[
                Text("Pressed: ${_snapshot.data}"),
                RaisedButton(child: Text("inc"), onPressed: () => { _bloc.eventSink.add(IncrementEvent()) },),
                RaisedButton(child: Text("dec"), onPressed: () => { _bloc.eventSink.add(DecrementEvent()) },)
                
              ],
            );
          }

        )


      ),
    );


  }

    @override
    dispose()
    {
      super.dispose();
      _bloc.dispose();
    }

}

class SplashScreen extends StatefulWidget {
  @override
  SplashScreenState createState() => SplashScreenState();
}

class SplashScreenState extends State<SplashScreen> {

  @override
  void initState() {
    myStreamController.stream.where((d) => d == 42).listen((_) { 
      // Navigator.pushNamed(context,  '/home');       
      Navigator.push(context,  ScaleRotateRoute(page: HomePage()));       

    });
    
    //  listen((data) {
    //   if (data == 42)
    //   {
    //     Navigator.pushNamed(context, '/home');
    //   }
    // });

    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(),
        body: Center(
          child: Container(
            child: DefaultTextStyle(
              style: TextStyle(
                fontSize: 34,
                color: Colors.black54
              ),
              child: StreamBuilder(
                  stream: myStreamController.stream,
                  builder: (context, snapshot) {
                    if (snapshot.hasData) {
                      switch (snapshot.data) {
                        case 1:
                          return Text("${snapshot.data}");
                        case 2:
                          return Text("${snapshot.data}");
                        case 3:
                          return Text("${snapshot.data}");
                        default:
                          return Text("${snapshot.data}");                          
                      }
                    } else
                      return CircularProgressIndicator();
                  })
            )
                  ),
        ));

    // return
  }
}