Two steps widget loader

main.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool isFirstStepFinished = false;
  bool isSecondStepFinished = false;

  int _counter = 0;

  @override
  void initState() {
    super.initState();
    loadFuturesStepByStep();
  }

  Future<void> loadFuturesStepByStep() async {
    await Future<void>.delayed(Duration(seconds: 2), () {});
    isFirstStepFinished = true;
    if (mounted) setState(() {});
    await Future<void>.delayed(Duration(seconds: 2), () {});
    isSecondStepFinished = true;
    if (mounted) setState(() {});
  }

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: AnimatedSwitcher(
          duration: kTabScrollDuration,
          child: isFirstStepFinished
              ? Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    AnimatedSwitcher(
                      duration: kTabScrollDuration,
                      child: isSecondStepFinished
                          ? Text(
                              'You have pushed the button this many times:',
                            )
                          : Text('Not finished yet, wait a sec...'),
                    ),
                    Text(
                      '$_counter',
                      style: Theme.of(context).textTheme.headline4,
                    ),
                  ],
                )
              : CircularProgressIndicator(),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}