package org.apidesign.friendpackage.impl;

 import javax.swing.event.ChangeListener;

 import org.apidesign.friendpackage.api.Item;

 /**

  *

  * @author Jaroslav Tulach

  */

 // BEGIN: design.less.friend.Accessor

 public abstract class Accessor {

     private static volatile Accessor DEFAULT;

     public static Accessor getDefault() {

         Accessor a = DEFAULT;

         if (a == null) {

             throw new IllegalStateException("Something is wrong: " + a);

         }

         return a;

     }

     public static void setDefault(Accessor accessor) {

         if (DEFAULT != null) {

             throw new IllegalStateException();

         }

         DEFAULT = accessor;

     }

     public Accessor() {

     }

     protected abstract Item newItem();

     protected abstract void addChangeListener(Item item, ChangeListener l);

 // FINISH: design.less.friend.Accessor

     // BEGIN: design.less.friend.InitAPI

     private static final Class<?> INIT_API_CLASS = loadClass(

         Item.class.getName()

     );

     private static Class<?> loadClass(String name) {

         try {

             return Class.forName(

                 name, true, Accessor.class.getClassLoader()

             );

         } catch (Exception ex) {

             throw new RuntimeException(ex);

         }

     }

     // END: design.less.friend.InitAPI

 }