/*
 * ListFacades.java
 * Copyright 2010 Connor Petty <cpmeister@users.sourceforge.net>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * 
 * Created on Apr 25, 2010, 4:29:53 PM
 */
package pcgen.facade.util;

import java.util.AbstractList;
import java.util.Iterator;
import java.util.List;

import pcgen.facade.util.event.ListListener;

/**
 *
 * @author Connor Petty <cpmeister@users.sourceforge.net>
 */
public final class ListFacades
{

	private ListFacades()
	{
		//Do not instantiate Utility Class
	}

	public static final ListFacade EMPTY_LIST = new EmptyList();

	public static <T> ListFacade<T> emptyList()
	{
		return EMPTY_LIST;
	}

	public static <T> List<T> wrap(final ListFacade<T> list)
	{
		return new AbstractList<T>()
		{

			@Override
			public T get(int index)
			{
				return list.getElementAt(index);
			}

			@Override
			public int size()
			{
				return list.getSize();
			}

		};
	}

	private static class EmptyList implements ListFacade
	{

		private static Iterator iterator = new Iterator()
		{

            @Override
			public boolean hasNext()
			{
				return false;
			}

            @Override
			public Object next()
			{
				throw new UnsupportedOperationException();
			}

            @Override
			public void remove()
			{
				throw new UnsupportedOperationException();
			}

		};

        @Override
		public void addListListener(ListListener listener)
		{
			//This list never changes so there's no point in listening to it
		}

        @Override
		public Object getElementAt(int index)
		{
			throw new IndexOutOfBoundsException();
		}

        @Override
		public int getSize()
		{
			return 0;
		}

        @Override
		public void removeListListener(ListListener listener)
		{
			//This list never changes so there's no point in listening to it
		}

        @Override
		public Iterator iterator()
		{
			return iterator;
		}

        @Override
		public boolean isEmpty()
		{
			return true;
		}

        @Override
		public boolean containsElement(Object element)
		{
			return false;
		}

	}

}