// PersonApplet.java

import  java.applet.*;
import  java.awt.*;
import  java.util.*;

public 
    class       PersonApplet
    extends     ObjectApplet
    implements  Observer
    {
    static final String oStringChangedAddress  = "changedAddress"  .intern();
    static final String oStringChangedName     = "changedName"     .intern();
    static final String oStringChangedPhone    = "changedPhone"    .intern();

    private TextField       oFieldName;
    private TextField       oFieldAddress;
    private TextField       oFieldPhone;
    private Person          oPerson;

//  CONSTRUCTORS

    public
        PersonApplet
        (
        )
        {
        init();
        }

//  PUBLIC METHODS

    public
        void    clear
        (
        )
        {
        setPerson(null);
        }

    public
        Object  getObject
        (
        )
        {
        return getPerson();
        }

    public
        Person getPerson
        (
        )
        {
        return oPerson;
        }

    public
        boolean handleEvent
        (
        Event poEvent
        )
        {
        Object      oObject;
        TextField   oTarget;

        if (    Event.ACTION_EVENT  == poEvent.id
            ||  Event.TAB           == poEvent.key)
            {
            oTarget = (TextField)poEvent.target;
            oObject = oPerson.objectForString(oTarget.getText());
            if (oFieldAddress == oTarget)
                getPerson().setAddress(oObject);
            else if (oFieldName == oTarget)
                getPerson().setName(oObject);
            else if (oFieldPhone == oTarget)
                getPerson().setPhone(oObject);
            }
        return super.handleEvent(poEvent);
        }

    public
        void    init
        (
        )
        {
        setLayout(new GridLayout(3,1,5,5));
        oFieldName       = new TextField(20);
        oFieldAddress    = new TextField(20);
        oFieldPhone      = new TextField(20);
        add(oFieldName);
        add(oFieldAddress);
        add(oFieldPhone);
        clear();
        }

    public
        void setObject
        (
        Object  poObject
        )
        {
        setPerson((Person)poObject);
        }

    public
        void setPerson
        (
        Person poPerson
        )
        {
        if (null != oPerson)
            oPerson.deleteObserver(this);
        oPerson = poPerson;
        if (null != oPerson)
            {
            oPerson.addObserver(this);
            oFieldName       .setText(oPerson.getName     ().toString());
            oFieldAddress    .setText(oPerson.getAddress  ().toString());
            oFieldPhone      .setText(oPerson.getPhone    ().toString());
            }
        else
            {
            oFieldName       .setText("");
            oFieldAddress    .setText("");
            oFieldPhone      .setText("");
            }
        }

    public
        void update
        (
        Observable  poPerson,
        Object      poString
        )
        {
        if (oPerson == poPerson)
            {
            if      (oStringChangedAddress == poString)
                oFieldAddress.setText(oPerson.getAddress().toString());
            else if (oStringChangedName    == poString)
                oFieldName.setText   (oPerson.getName   ().toString());
            else if (oStringChangedPhone   == poString)
                oFieldPhone.setText  (oPerson.getPhone  ().toString());
            }
        }
    }