1/**
2 * $RCSfile$
3 * $Revision$
4 * $Date$
5 *
6 * Copyright 2003-2007 Jive Software.
7 *
8 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 *     http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21package org.jivesoftware.smack.filter;
22
23import org.jivesoftware.smack.packet.Packet;
24
25/**
26 * Implements the logical NOT operation on a packet filter. In other words, packets
27 * pass this filter if they do not pass the supplied filter.
28 *
29 * @author Matt Tucker
30 */
31public class NotFilter implements PacketFilter {
32
33    private PacketFilter filter;
34
35    /**
36     * Creates a NOT filter using the specified filter.
37     *
38     * @param filter the filter.
39     */
40    public NotFilter(PacketFilter filter) {
41        if (filter == null) {
42            throw new IllegalArgumentException("Parameter cannot be null.");
43        }
44        this.filter = filter;
45    }
46
47    public boolean accept(Packet packet) {
48        return !filter.accept(packet);
49    }
50}
51