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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      navigatorKey: Get.key,
      initialRoute: "/",
      navigatorObservers: [
        GetObserver(MiddleWare.observer),
      ],
      onGenerateRoute: Router.generateRoute,
    );
  }
}

class MiddleWare {
  static observer(Routing routing) {
    ///Trigger any event when a route is pushed or popped by Get. 
    /// You can listen in addition to the routes, the snackbars, dialogs and bottomsheets on each screen. 
    ///If you need to enter any of these 3 events directly here, 
    ///you must specify that the event is != Than you are trying to do.
    if (routing.current == '/second' && !routing.isSnackbar) {
      Get.snackbar("Hi", "You are on second route");
    } else if (routing.current =='/third'){
      print('last route called');
    }
  }
}

class First extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: Icon(Icons.add),
          onPressed: () {
            Get.snackbar("hi", "i am a modern snackbar");
          },
        ),
        title: Text('First Route'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Open route'),
          onPressed: () {
            Get.toNamed("/second");
          },
        ),
      ),
    );
  }
}

class Second extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: Icon(Icons.add),
          onPressed: () {
            Get.snackbar("hi", "i am a modern snackbar");
          },
        ),
        title: Text('second Route'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Open route'),
          onPressed: () {
            Get.toNamed("/third");
          },
        ),
      ),
    );
  }
}

class Third extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Third Route"),
      ),
      body: Center(
        child: RaisedButton(
          onPressed: () {
            Get.back();
          },
          child: Text('Go back!'),
        ),
      ),
    );
  }
}

class Router {
  static Route<dynamic> generateRoute(RouteSettings settings) {
    switch (settings.name) {
      case '/':
        return GetRoute(
          page: First(),
          settings: settings,
        );
      case '/second':
        return GetRoute(
            settings: settings, page: Second(), transition: Transition.fade);
      case '/third':
        return GetRoute(
            settings: settings,
            page: Third(),
            transition: Transition.rightToLeft);
      default:
        return GetRoute(
            settings: settings,
            transition: Transition.fade,
            page: Scaffold(
              body:
                  Center(child: Text('No route defined for ${settings.name}')),
            ));
    }
  }
}