001/**
002 *
003 * Copyright 2020 Paul Schaub
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.smackx.message_retraction;
018
019import java.util.Map;
020import java.util.WeakHashMap;
021
022import org.jivesoftware.smack.ConnectionCreationListener;
023import org.jivesoftware.smack.Manager;
024import org.jivesoftware.smack.SmackException;
025import org.jivesoftware.smack.XMPPConnection;
026import org.jivesoftware.smack.XMPPConnectionRegistry;
027import org.jivesoftware.smack.packet.MessageBuilder;
028
029import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
030import org.jivesoftware.smackx.message_fastening.element.FasteningElement;
031import org.jivesoftware.smackx.message_retraction.element.RetractElement;
032import org.jivesoftware.smackx.sid.element.OriginIdElement;
033
034/**
035 * Smacks API for XEP-0424: Message Retraction.
036 *
037 * To enable / disable auto-announcing support for this feature, call {@link #setEnabledByDefault(boolean)}.
038 * Auto-announcing is enabled by default.
039 *
040 * To retract a message, call {@link #retractMessage(OriginIdElement)}, passing in the {@link OriginIdElement Origin ID}
041 * of the message to be retracted.
042 */
043public final class MessageRetractionManager extends Manager {
044
045    private static final Map<XMPPConnection, MessageRetractionManager> INSTANCES = new WeakHashMap<>();
046
047    private static boolean ENABLED_BY_DEFAULT = false;
048
049    static {
050        XMPPConnectionRegistry.addConnectionCreationListener(new ConnectionCreationListener() {
051            @Override
052            public void connectionCreated(XMPPConnection connection) {
053                if (ENABLED_BY_DEFAULT) {
054                    getInstanceFor(connection).announceSupport();
055                }
056            }
057        });
058    }
059
060    private MessageRetractionManager(XMPPConnection connection) {
061        super(connection);
062    }
063
064    public static synchronized MessageRetractionManager getInstanceFor(XMPPConnection connection) {
065        MessageRetractionManager manager = INSTANCES.get(connection);
066        if (manager == null) {
067            manager = new MessageRetractionManager(connection);
068            INSTANCES.put(connection, manager);
069        }
070        return manager;
071    }
072
073    /**
074     * Enable or disable auto-announcing support for Message Retraction.
075     * Default is disabled.
076     *
077     * @param enabled enabled
078     */
079    public static synchronized void setEnabledByDefault(boolean enabled) {
080        ENABLED_BY_DEFAULT = enabled;
081    }
082
083    /**
084     * Announce support for Message Retraction to the server.
085     *
086     * @see <a href="https://xmpp.org/extensions/xep-0424.html#disco">XEP-0424: Message Retraction: ยง2. Discovering Support</a>
087     */
088    public void announceSupport() {
089        ServiceDiscoveryManager.getInstanceFor(connection()).addFeature(RetractElement.NAMESPACE);
090    }
091
092    /**
093     * Stop announcing support for Message Retraction.
094     */
095    public void stopAnnouncingSupport() {
096        ServiceDiscoveryManager.getInstanceFor(connection()).removeFeature(RetractElement.NAMESPACE);
097    }
098
099    /**
100     * Append a {@link RetractElement} wrapped inside a {@link FasteningElement} which contains
101     * the {@link OriginIdElement Origin-ID} of the message that will be retracted to the given {@link MessageBuilder}.
102     *
103     * @param retractedMessageId {@link OriginIdElement OriginID} of the message that the user wants to retract
104     * @param carrierMessageBuilder message used to transmit the message retraction to the recipient
105     */
106    public static void addRetractionElementToMessage(OriginIdElement retractedMessageId, MessageBuilder carrierMessageBuilder) {
107        FasteningElement fasteningElement = FasteningElement.builder()
108                .setOriginId(retractedMessageId)
109                .addWrappedPayload(new RetractElement())
110                .build();
111        fasteningElement.applyTo(carrierMessageBuilder);
112    }
113
114    /**
115     * Retract a message by appending a {@link RetractElement} wrapped inside a {@link FasteningElement} which contains
116     * the {@link OriginIdElement Origin-ID} of the message that will be retracted to a new message and send it to the
117     * server.
118     *
119     * @param retractedMessageId {@link OriginIdElement OriginID} of the message that the user wants to retract
120     * @throws SmackException.NotConnectedException in case the connection is not connected.
121     * @throws InterruptedException if the thread gets interrupted.
122     */
123    public void retractMessage(OriginIdElement retractedMessageId)
124            throws SmackException.NotConnectedException, InterruptedException {
125        MessageBuilder message = connection().getStanzaFactory().buildMessageStanza();
126        addRetractionElementToMessage(retractedMessageId, message);
127        connection().sendStanza(message.build());
128    }
129}