A Decision Making App

main.dart

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

void main() => runApp(
      MaterialApp(
        home: Scaffold(
          backgroundColor: Colors.blueAccent,
          appBar: AppBar(
            title: Text("Ask Me Anything"),
          ),
          body: MagicBall(),
        ),
      ),
    );

class MagicBall extends StatefulWidget {
  @override
  _MagicBallState createState() => _MagicBallState();
}

class _MagicBallState extends State<MagicBall> {
  var ballNumber = 1;

  void changeMagicNumber() {
    setState(() {
      ballNumber = Random().nextInt(5) + 1;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Center(
      child: FlatButton(
        onPressed: () {
          changeMagicNumber();
        },
        child: Image.asset('images/ball$ballNumber.png'),
      ),
    );
  }
}