The ClaimWizard uses an internal page field (of type Page enum) to determine which page the user is on; from this we determine which properties should be visible, and whether the previous(), next() and finish() actions are available.

package org.nakedobjects.examples.claims.dom.claim;

import java.util.Calendar;
import java.util.List;

import org.nakedobjects.applib.AbstractDomainObject;
import org.nakedobjects.applib.annotation.Disabled;
import org.nakedobjects.applib.annotation.Hidden;
import org.nakedobjects.applib.annotation.Ignore;
import org.nakedobjects.applib.annotation.MemberOrder;
import org.nakedobjects.applib.annotation.NotPersistable;
import org.nakedobjects.applib.annotation.TypicalLength;
import org.nakedobjects.applib.clock.Clock;
import org.nakedobjects.examples.claims.dom.employee.EmployeeRepository;
import org.starobjects.wicket.applib.WizardPageDescription;

@NotPersistable
public class ClaimWizard extends AbstractDomainObject {

    public enum Page {
        INTRO("This wizard will take you through the process of creating a claim"), 
        CLAIMANT("Enter the claimant that is making this claim"), 
        APPROVER("By default, the claimant's own approver will approve this claim.  " +
                 "Update here if another approver will approve this claim."), 
        DESCRIPTION("Update the description if required."), 
        SUMMARY("Confirm all details, or go back and amend if needed");

        private String description;
        private Page(String description) {
            this.description = description;
        }

        public String getDescription() {
            return description;
        }

        public boolean hasPrevious() {
            return ordinal() > 0;
        }
        public Page previous() {
            if (hasPrevious()) {
                return values()[ordinal() - 1];
            } else {
                return this;
            }
        }

        public boolean hasNext() {
            return ordinal() < values().length - 1;
        }
        public Page next() {
            if (hasNext()) {
                return values()[ordinal() + 1];
            } else {
                return this;
            }
        }

        @Ignore
        public boolean is(Page... pages) {
            for (Page page : pages) {
                if (page == this) {
                    return true;
                }
            }
            return false;
        }
    }

    // {{ Lifecycle
    public void created() {
        setPage(Page.INTRO);
        setDescription("Expenses for week #" + weekNum());
    }
    private int weekNum() {
        return getTimeAsCalendar().get(Calendar.WEEK_OF_YEAR);
    }
    protected Calendar getTimeAsCalendar() {
        return Clock.getTimeAsCalendar();
    }
    // }}

    // {{ Page
    private Page page;
    @Hidden
    public Page getPage() { ... }
    public void setPage(final Page page) { ... }
    // }}

    // {{ Page Description
    @WizardPageDescription
    @TypicalLength(60)
    @MemberOrder(sequence = "1")
    public String getPageDescription() {
        return getPage().getDescription();
    }
    // }}

    // {{ Claimant
    private Claimant claimant;
    @MemberOrder(sequence = "2")
    public Claimant getClaimant() { ... }
    public void setClaimant(final Claimant claimant) { ... }
    public void modifyClaimant(final Claimant claimant) { ... }
    public void clearClaimant() { ... }
    }
    protected void onModifyClaimant(final Claimant oldClaimant,
            final Claimant newClaimant) {
        setApprover(newClaimant.getApprover());
    }
    protected void onClearClaimant(final Claimant oldClaimant) {
    }
    @SuppressWarnings("unchecked")
    public List<Claimant> choicesClaimant() {
        return employeeRepository.allEmployees();
    }
    public String disableClaimant() {
        return coalesce(claimCreated(), confirmIfOnSummaryPage());
    }
    public boolean hideClaimant() {
        return !getPage().is(Page.CLAIMANT, Page.SUMMARY);
    }
    // }}

    // {{ Approver
    private Approver approver;
    @MemberOrder(sequence = "3")
    public Approver getApprover() { ... }
    public void setApprover(final Approver approver) { ... }
    public String disableApprover() {
        return coalesce(claimCreated(), confirmIfOnSummaryPage());
    }
    public boolean hideApprover() {
        return !getPage().is(Page.APPROVER, Page.SUMMARY);
    }
    // }}

    // {{ Description
    private String description;
    @MemberOrder(sequence = "4")
    public String getDescription() { ... }
    public void setDescription(final String description) { ... }
    public String disableDescription() {
        return coalesce(claimCreated(), confirmIfOnSummaryPage());
    }
    public boolean hideDescription() {
        return !getPage().is(Page.DESCRIPTION, Page.SUMMARY);
    }
    private String claimCreated() {
        return claim != null ? "Claim created" : null;
    }
    // }}

    // {{ Claim
    private Claim claim;
    @Disabled
    @MemberOrder(sequence = "5")
    public Claim getClaim() { ... }
    public void setClaim(final Claim claim) { ... }
    public boolean hideClaim() { ... }
    // }}

    // {{ previous
    @MemberOrder(sequence = "1")
    public void previous() {
        setPage(getPage().previous());
    }
    public String disablePrevious() {
        return coalesce(noPreviousPage(), confirmIfOnSummaryPage());
    }
    private String noPreviousPage() {
        return !getPage().hasPrevious() ? "no previous page" : null;
    }
    // }}

    // {{ next
    @MemberOrder(sequence = "2")
    public void next() {
        setPage(getPage().next());
    }
    public String disableNext() {
        return coalesce(noNextPage(), confirmIfOnSummaryPage());
    }
    private String noNextPage() {
        return !getPage().hasNext() ? "no next page" : null;
    }
    // }}

    // {{ finish
    @MemberOrder(sequence = "3")
    public Claim finish() {
        Claim claim = newTransientInstance(Claim.class);
        claim.setClaimant(getClaimant());
        claim.setApprover(getApprover());
        claim.setDescription(getDescription());
        setClaim(claim);
        persist(claim);
        return claim;
    }
    public String disableFinish() {
        if (getPage().hasNext()) {
            return "wizard has further pages to complete";
        }
        return getContainer().validate(this);
    }
    // }}

    // {{ helpers
    private String confirmIfOnSummaryPage() {
        return getPage().is(Page.SUMMARY) ? "confirm" : null;
    }
    private static String coalesce(String... strings) {
        for (String string : strings) {
            if (string != null)
                return string;
        }
        return null;
    }
    // }}

    // {{ injected: EmployeeRepository
    private EmployeeRepository employeeRepository;
    public void setEmployeeRepository(
            final EmployeeRepository employeeRepository) { ... }
    // }}
}

The ClaimExpenseSummary is used as a report object:

package org.nakedobjects.examples.claims.dom.claim;

import org.nakedobjects.applib.annotation.Disabled;
import org.nakedobjects.applib.annotation.Ignore;
import org.nakedobjects.applib.annotation.MemberOrder;
import org.nakedobjects.applib.annotation.NotPersistable;
import org.nakedobjects.applib.value.Money;
import org.starobjects.wicket.applib.PieChartable;

@NotPersistable
public class ClaimantExpenseSummary implements PieChartable,
        Comparable<ClaimantExpenseSummary> {

    // {{ Identification
    public String title() {
        return getClaimant() != null ? getClaimant().title() : "(untitled)";
    }
    // }}

    // {{ Claimant
    private Claimant claimant;
    @MemberOrder(sequence = "1")
    public Claimant getClaimant() { ... }
    public void setClaimant(final Claimant claimant) { ... }
    // }}

    // {{ Amount
    private Money amount;
    @Disabled
    @MemberOrder(sequence = "1")
    public Money getAmount() { ... }
    public void setAmount(final Money amount) { ... }
    // }}

    // {{ programmatic
    @Ignore
    public void addAmount(Money amount) {
        if (this.amount == null) {
            this.amount = amount;
        } else {
            this.amount = this.amount.add(amount);
        }
    }
    // }}

    // {{ PieChartable impl
    @Ignore
    @Override
    public double getPieChartValue() {
        return getAmount().doubleValue();
    }
    @Ignore
    @Override
    public String getPieChartLabel() {
        return title();
    }
    // }}

    @Override
    public int compareTo(ClaimantExpenseSummary o) {
        if (getPieChartValue() < o.getPieChartValue())
            return -1;
        if (getPieChartValue() > o.getPieChartValue())
            return +1;
        return 0;
    }
}

Note that it implements the (rather horribly named) PieChartable, which is picked up by the googlecharts custom component (see Section 5.3, “Google Charts”).