client/lib/main.dart

import 'package:flutter/material.dart';
import 'package:after_layout/after_layout.dart';
import 'package:shared_preferences/shared_preferences.dart';
// import 'lobby_screen.dart';
import  'setup_screen.dart';
import  'home_screen.dart';
import 'loading.dart';

/*
 * in flutter everything is a widget 
 */


void main() { // main function
  runApp(const MainApp());  // control starts here
}

class MainApp extends StatelessWidget { // statelessWidget means a class which will not have an persistent state
  const MainApp({super.key});

  @override
  Widget build(BuildContext context) {  // Every Widget has a build method
    return MaterialApp(
      title:'HapticLink',
      debugShowCheckedModeBanner: false,
      theme:ThemeData.dark(),
      // home: SetupScreen(),
      // home: Loading(),
      home: const Splash(), // Splash Screen
    );
  }
}

class Splash extends StatefulWidget { 
  const Splash({super.key});
  @override
  State<Splash> createState(){
    return SplashState();
  }
}

class SplashState extends State<Splash> with AfterLayoutMixin<Splash>{

  void checkFirstScreen() async{
    SharedPreferences prefs = await SharedPreferences.getInstance();  // this is the local storage of any device
    
    // if prefs:"setup_done" not set
    if(prefs.getBool('setup_done')==null){  // if we are using the app for the first time
      // go to Setup Screen
      Navigator.pushReplacement(
        context,
        MaterialPageRoute(
          builder: (context)=>SetupScreen() // go to SetupScreen
          )
        );
    }
    else{ 
      // otherwise go to Home Screen directly
      Navigator.pushReplacement(
        context,
        MaterialPageRoute(
          builder: (context)=>HomeScreen()  // go to HomeScreen
          )
        );
    }
  }
  @override
  void afterFirstLayout(BuildContext context){  // because of AfterLayoutMixin this method is called automatically after the build method
    checkFirstScreen();
  }
  @override
  Widget build(BuildContext context){
    return const Loading(); // by default show the loading Widget(Screen)
  }
}