Stepper({Key key, List<Step> steps, StepperType type: StepperType.vertical, int currentStep: 0, ValueChanged<int> onStepTapped, VoidCallback onStepContinue, VoidCallback onStepCancel })

Creates a stepper from a list of steps.

This widget is not meant to be rebuilt with a different list of steps unless a key is provided in order to distinguish the old stepper from the new one.

The steps, type, and currentStep arguments must not be null.

Source 

Stepper({
  Key key,
  this.steps,
  this.type: StepperType.vertical,
  this.currentStep: 0,
  this.onStepTapped,
  this.onStepContinue,
  this.onStepCancel
}) : super(key: key) {
  assert(this.steps != null);
  assert(this.type != null);
  assert(this.currentStep != null);
  assert(0 <= currentStep && currentStep < this.steps.length);
}