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

}