public WizardPanel(String id) {
    super(id, false);
    // false deactivates the default style.
    setDefaultModel(new CompoundPropertyModel<WizardPanel>(this));
    WizardModel model = new WizardModel();
    model.add(new FirstStep());
    model.add(new SecondStep());
    model.add(new ThirdStep());
    model.add(new ConfirmationStep());

    Iterator<IWizardStep> iterator = model.stepIterator();
    for(int i = 1; iterator.hasNext(); i ++){
        System.out.println(String.valueOf(i));
    }
    init(model);
}

public class OverviewComponent extends Panel{
    private static final long serialVersionUID = 1L;
    private List<WizardStep> steps;
    private WizardModel model;

    public OverviewComponent(String id, WizardModel model) {
        super(id);
        this.model = model;
        steps = fillList();

        this.add(new ListView<WizardStep>("steps", steps) {
            private static final long serialVersionUID = 1L;
            /**
             * Wrap a markup container around the item append a css attribute to every item
             */
            @Override
            protected void populateItem(ListItem<WizardStep> item) {
                WebMarkupContainer stepOverviewItem;
                item.add(stepOverviewItem = new WebMarkupContainer("stepOverviewItem"));
                stepOverviewItem.add(new Label("index", Model.of(item.getIndex()+1)));
                stepOverviewItem.add(new AttributeModifier("class", getCSSProperty(item.getModelObject())));
                stepOverviewItem.setOutputMarkupId(true);
                stepOverviewItem.setOutputMarkupPlaceholderTag(true);
            }

        });
    }

    public String getCSSProperty(WizardStep step) {
        if (step.equals(model.getActiveStep())) {
            return "active";
        } else if (!step.isComplete()) {
            return "pending";
        } else if (step.isComplete()) {
            return "completed";
        }
        return "";
    }

    public List<WizardStep> fillList() {
        List<WizardStep> iSteps = new ArrayList<WizardStep>();
        Iterator<IWizardStep> iterator = model.stepIterator();
        while (iterator.hasNext()) {
            iSteps.add((WizardStep)iterator.next());
        }
        return iSteps;
    }
}