/*

  * Created on Jul 3, 2004

  *

  * To change the template for this generated file go to

  * Window - Preferences - Java - Code Generation - Code and Comments

  */

 package biz.xsoftware.examples.listener;

 import java.util.HashSet;

 import java.util.Set;

 import javax.swing.event.EventListenerList;

 /**

  * 

  * @author Dean Hiller

  */

 public class UserServiceImpl implements UserService {

         private EventListenerList listenerList = new EventListenerList();

         private Set<String> names = new HashSet<String>();

         public UserServiceImpl() {

         }

         /**

      * @see biz.xsoftware.examples.listener.UserService#addUser(java.lang.String)

      */

         public void addUser(String userName) {

                 if(names.contains(userName))

                         throw new IllegalArgumentException("The user="+userName+" is already in the system");

                 names.add(userName);

                 fireUserAdded(userName);

         }

         /**

      * @see biz.xsoftware.examples.listener.UserService#deleteUser(java.lang.String)

      */

         public void deleteUser(String userName) {                

                 boolean isRemoved = names.remove(userName);

                 if(!isRemoved)

                         throw new IllegalArgumentException("The user="+userName+" is not in the system");

                 fireUserDeleted(userName);

         }

         /**

      * @see biz.xsoftware.examples.listener.UserService#addUserListener(biz.xsoftware.examples.listener.UserListener)

      */

         public void addUserListener(UserListener l) {

                 listenerList.add(UserListener.class, l);

         }

         /**

      * @see biz.xsoftware.examples.listener.UserService#removeUserListener(biz.xsoftware.examples.listener.UserListener)

      */

         public void removeUserListener(UserListener l) {

                 listenerList.remove(UserListener.class, l);

         }

         protected void fireUserAdded(String userName) {

                 // Guaranteed to return a non-null array

                 Object[] listeners = listenerList.getListenerList();

                 // Process the listeners last to first, notifying

                 // those that are interested in this event

                 for (int i = listeners.length-2; i>=0; i-=2) {

                         if (listeners[i]==UserListener.class) {

                                 // Lazily create the event:

                                 ((UserListener)listeners[i+1]).userAdded(userName);

                         }

                 }

         }        

         protected void fireUserDeleted(String userName) {

                 // Guaranteed to return a non-null array

                 Object[] listeners = listenerList.getListenerList();

                 // Process the listeners last to first, notifying

                 // those that are interested in this event

                 for (int i = listeners.length-2; i>=0; i-=2) {

                         if (listeners[i]==UserListener.class) {

                                 // Lazily create the event:

                                 ((UserListener)listeners[i+1]).userDeleted(userName);

                         }

                 }

         }        

 }