001/**
002 *
003 * Copyright 2003-2007 Jive Software.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.jivesoftware.smack.filter;
019
020import org.jivesoftware.smack.packet.Packet;
021
022/**
023 * Implements the logical NOT operation on a packet filter. In other words, packets
024 * pass this filter if they do not pass the supplied filter.
025 *
026 * @author Matt Tucker
027 */
028public class NotFilter implements PacketFilter {
029
030    private PacketFilter filter;
031
032    /**
033     * Creates a NOT filter using the specified filter.
034     *
035     * @param filter the filter.
036     */
037    public NotFilter(PacketFilter filter) {
038        if (filter == null) {
039            throw new IllegalArgumentException("Parameter must not be null.");
040        }
041        this.filter = filter;
042    }
043
044    public boolean accept(Packet packet) {
045        return !filter.accept(packet);
046    }
047}