Render UI with delay

main.dart

import 'package:flutter_web/material.dart';
import 'package:flutter_web_ui/ui.dart' as ui;

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Demo',
      home: Scaffold(
        appBar: AppBar(
          title: Text('Demo'),
        ),
        body: Center(
          child: FutureBuilder(
            future: Future.delayed(Duration(seconds: 5), () => true),
            builder: (context, snapshot){
              if(!snapshot.hasData)
              return CircularProgressIndicator();
              
              return Text("Yay");
            } 
          )
        ),
      ),
    );
  }
}


Future<void> main() async {
  await ui.webOnlyInitializePlatform();

  runApp(MyApp());
}