/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cocoon.portal.pluto.om.common;

import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;

/**
 * 
 *
 * @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
 * 
 * @version CVS $Id$
 */
public class UnmodifiableSet implements Set, Serializable {

    // use serialVersionUID from JDK 1.2.2 for interoperability
    private static final long serialVersionUID = 1820017752578914078L;

    protected Set c;

    public UnmodifiableSet(Set c) {
        if (c == null) {
            throw new NullPointerException();
        }
        this.c = c;
    }

    public int size() {
        return c.size();
    }

    public boolean isEmpty() {
        return c.isEmpty();
    }

    public boolean contains(Object o) {
        return c.contains(o);
    }

    public Object[] toArray() {
        return c.toArray();
    }

    public Object[] toArray(Object[] a) {
        return c.toArray(a);
    }

    public String toString() {
        return c.toString();
    }

    public Iterator iterator() {
        return new Iterator() {
            Iterator i = c.iterator();

            public boolean hasNext() {
                return i.hasNext();
            }

            public Object next() {
                return i.next();
            }

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

    public boolean add(Object o) {
        throw new UnsupportedOperationException();
    }

    public boolean remove(Object o) {
        throw new UnsupportedOperationException();
    }

    public boolean containsAll(Collection coll) {
        return c.containsAll(coll);
    }

    public boolean addAll(Collection coll) {
        throw new UnsupportedOperationException();
    }

    public boolean removeAll(Collection coll) {
        throw new UnsupportedOperationException();
    }

    public boolean retainAll(Collection coll) {
        throw new UnsupportedOperationException();
    }

    public void clear() {
        throw new UnsupportedOperationException();
    }

    public boolean equals(Object o) {
        return c.equals(o);
    }

    public int hashCode() {
        return c.hashCode();
    }

    // additional methods.

    /**
     * This method is only used by the ControllerFactoryImpl
     * to unwrap the unmodifiable Set and allow to
     * modify the set via controllers
     * 
     * @return the modifiable set
     */
    public Set getModifiableSet() {
        return c;
    }
}