Flutter Stepper

import 'package:flutter/material.dart';

void main() =>
    runApp(new MaterialApp(title: "Simple Material App", home: new MyHome()));

class MyHome extends StatefulWidget {
  @override
  State createState() => MyHomeState();
}

class MyHomeState extends State {
  int current_step = 0;
  List my_steps = [
    new Step(
        title: new Text("Step 1"), content: new Text("Hello"), isActive: true),
    new Step(
        title: new Text("Step 2"), content: new Text("World"), isActive: true),
    new Step(
        title: new Text("Step 3"),
        content: new Text("Hello World"),
        isActive: true)
  ];
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar:
          new AppBar(title: new Center(child: new Text("Simple Material App"))),
      body: new Container(
        child: new Stepper(
          currentStep: this.current_step,
          steps: my_steps,
          type: StepperType.vertical,
          onStepTapped: (step) {
            setState(() {
              current_step = step;
            });
          },
          onStepCancel: () {
            setState(() {
              if (current_step > 0) {
                current_step = current_step - 1;
              } else {
                current_step = 0;
              }
            });
          },
          onStepContinue: () {
            setState(() {
              if (current_step < my_steps.length - 1) {
                current_step = current_step + 1;
              } else {
                current_step = 0;
              }
            });
          },
        ),
      ),
    );
  }
}