001/**
002 *
003 * Copyright 2020 Florian Schmaus
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 */
017package org.jivesoftware.smack.filter;
018
019import javax.xml.namespace.QName;
020
021import org.jivesoftware.smack.packet.ExtensionElement;
022import org.jivesoftware.smack.packet.Stanza;
023import org.jivesoftware.smack.util.XmppElementUtil;
024
025public class ExtensionElementFilter<E extends ExtensionElement> implements StanzaFilter {
026
027    private final Class<E> extensionElementClass;
028    private final QName extensionElementQName;
029
030    protected ExtensionElementFilter(Class<E> extensionElementClass) {
031        this.extensionElementClass = extensionElementClass;
032        extensionElementQName = XmppElementUtil.getQNameFor(extensionElementClass);
033    }
034
035    @Override
036    public final boolean accept(Stanza stanza) {
037        ExtensionElement extensionElement = stanza.getExtension(extensionElementQName);
038        if (extensionElement == null) {
039            return false;
040        }
041
042        if (!extensionElementClass.isInstance(extensionElement)) {
043            return false;
044        }
045
046        E specificExtensionElement = extensionElementClass.cast(extensionElement);
047        return accept(specificExtensionElement);
048    }
049
050    public boolean accept(E extensionElement) {
051        return true;
052    }
053}