001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.hivemind.impl;
016
017import java.util.AbstractList;
018import java.util.List;
019
020import org.apache.hivemind.HiveMind;
021import org.apache.hivemind.events.RegistryShutdownListener;
022
023/**
024 * The List implementation visible to the client code. It defers
025 * to another inner implementation of List; initially this is
026 * a {@link org.apache.hivemind.impl.ElementsInnerProxyList}, but the
027 * inner proxy replaces itself with a real List implementation containing
028 * the actual configuration elements.
029 *
030 * @author Howard Lewis Ship
031 */
032public final class ElementsProxyList extends AbstractList implements RegistryShutdownListener
033{
034    private List _inner;
035    private boolean _shutdown;
036
037    public void registryDidShutdown()
038    {
039        _shutdown = true;
040        _inner = null;
041    }
042
043    private void checkShutdown()
044    {
045        if (_shutdown)
046            throw HiveMind.createRegistryShutdownException();
047    }
048
049    public Object get(int index)
050    {
051        checkShutdown();
052
053        return _inner.get(index);
054    }
055
056    public int size()
057    {
058        checkShutdown();
059
060        return _inner.size();
061    }
062
063    public String toString()
064    {
065        return _inner.toString();
066    }
067
068    public boolean equals(Object o)
069    {
070        return _inner.equals(o);
071    }
072
073    public int hashCode()
074    {
075        return _inner.hashCode();
076    }
077
078    public void setInner(List list)
079    {
080        _inner = list;
081    }
082
083}