Wizard.java

package pt.ist.vaadinframework.ui.wizard;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import com.vaadin.ui.CustomComponent;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.Window;

/**
 * @author David Martinho (davidmartinho@ist.utl.pt)
 */
public abstract class Wizard extends CustomComponent {

    public interface CloseListener {
        public void onWizardClose(Wizard wizard);
    }

    private Set<CloseListener> closeListenerSet = new HashSet<CloseListener>();

    private VerticalLayout container;

    private List<WizardStep> stepHistoryList;
    private int currentStep = 0;

    public Wizard(WizardStep initialStep) {
        stepHistoryList = new ArrayList<WizardStep>();
        initialStep.setWizard(this);
        stepHistoryList.add(initialStep);
        bindUi();
    }

    private void bindUi() {
        container = new VerticalLayout();
        container.setSpacing(true);
        setCompositionRoot(container);
    }

    public WizardStep getCurrentStep() {
        if (stepHistoryList.size() > 0) {
            return stepHistoryList.get(currentStep);
        } else {
            return null;
        }
    }

    public void startWizard() {
        setCurrentStep(getCurrentStep());
    }

    public void goToNextStep() {
        WizardStep nextStep = getCurrentStep().getNextStep();
        if (nextStep != null) {
            nextStep.setWizard(getCurrentStep().getWizard());
            stepHistoryList.add(nextStep);
            currentStep++;
            setCurrentStep(nextStep);
        }
    }

    public void goToPreviousStep() {
        stepHistoryList.remove(getCurrentStep());
        currentStep--;
        setCurrentStep(getCurrentStep());
    }

    private void setCurrentStep(WizardStep wizardStep) {
        container.removeAllComponents();
        container.addComponent(wizardStep);
    }

    public final void close() {
        for (CloseListener closeListener : closeListenerSet) {
            closeListener.onWizardClose(this);
        }
        Window subwindow = getWindow();
        (subwindow.getParent()).removeWindow(subwindow);
    }

    public void commit() {
        for (WizardStep wizardStep : stepHistoryList) {
            wizardStep.commit();
        }
    }

    public void addListener(CloseListener closeListener) {
        closeListenerSet.add(closeListener);
    }
}