/**
* Copyright 2013 Georg Lukas
*
* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jivesoftware.smackx.carbons;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import org.jivesoftware.smack.Connection;
import org.jivesoftware.smack.ConnectionCreationListener;
import org.jivesoftware.smack.PacketCollector;
import org.jivesoftware.smack.PacketListener;
import org.jivesoftware.smack.SmackConfiguration;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.filter.PacketIDFilter;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smackx.ServiceDiscoveryManager;
import org.jivesoftware.smackx.packet.DiscoverInfo;
/**
* Packet extension for XEP-0280: Message Carbons. This class implements
* the manager for registering {@link Carbon} support, enabling and disabling
* message carbons.
*
* You should call enableCarbons() before sending your first undirected
* presence.
*
* @author Georg Lukas
*/
public class CarbonManager {
private static Map<Connection, CarbonManager> instances =
Collections.synchronizedMap(new WeakHashMap<Connection, CarbonManager>());
static {
Connection.addConnectionCreationListener(new ConnectionCreationListener() {
public void connectionCreated(Connection connection) {
new CarbonManager(connection);
}
});
}
private Connection connection;
private volatile boolean enabled_state = false;
private CarbonManager(Connection connection) {
ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection);
sdm.addFeature(Carbon.NAMESPACE);
this.connection = connection;
instances.put(connection, this);
}
/**
* Obtain the CarbonManager responsible for a connection.
*
* @param connection the connection object.
*
* @return a CarbonManager instance
*/
public static CarbonManager getInstanceFor(Connection connection) {
CarbonManager carbonManager = instances.get(connection);
if (carbonManager == null) {
carbonManager = new CarbonManager(connection);
}
return carbonManager;
}
private IQ carbonsEnabledIQ(final boolean new_state) {
IQ setIQ = new IQ() {
public String getChildElementXML() {
return "<" + (new_state? "enable" : "disable") + " xmlns='" + Carbon.NAMESPACE + "'/>";
}
};
setIQ.setType(IQ.Type.SET);
return setIQ;
}
/**
* Returns true if XMPP Carbons are supported by the server.
*
* @return true if supported
*/
public boolean isSupportedByServer() {
try {
DiscoverInfo result = ServiceDiscoveryManager
.getInstanceFor(connection).discoverInfo(connection.getServiceName());
return result.containsFeature(Carbon.NAMESPACE);
}
catch (XMPPException e) {
return false;
}
}
/**
* Notify server to change the carbons state. This method returns
* immediately and changes the variable when the reply arrives.
*
* You should first check for support using isSupportedByServer().
*
* @param new_state whether carbons should be enabled or disabled
*/
public void sendCarbonsEnabled(final boolean new_state) {
IQ setIQ = carbonsEnabledIQ(new_state);
connection.addPacketListener(new PacketListener() {
public void processPacket(Packet packet) {
IQ result = (IQ)packet;
if (result.getType() == IQ.Type.RESULT) {
enabled_state = new_state;
}
connection.removePacketListener(this);
}
}, new PacketIDFilter(setIQ.getPacketID()));
connection.sendPacket(setIQ);
}
/**
* Notify server to change the carbons state. This method blocks
* some time until the server replies to the IQ and returns true on
* success.
*
* You should first check for support using isSupportedByServer().
*
* @param new_state whether carbons should be enabled or disabled
*
* @return true if the operation was successful
*/
public boolean setCarbonsEnabled(final boolean new_state) {
if (enabled_state == new_state)
return true;
IQ setIQ = carbonsEnabledIQ(new_state);
PacketCollector collector =
connection.createPacketCollector(new PacketIDFilter(setIQ.getPacketID()));
connection.sendPacket(setIQ);
IQ result = (IQ) collector.nextResult(SmackConfiguration.getPacketReplyTimeout());
collector.cancel();
if (result != null && result.getType() == IQ.Type.RESULT) {
enabled_state = new_state;
return true;
}
return false;
}
/**
* Helper method to enable carbons.
*
* @return true if the operation was successful
*/
public boolean enableCarbons() {
return setCarbonsEnabled(true);
}
/**
* Helper method to disable carbons.
*
* @return true if the operation was successful
*/
public boolean disableCarbons() {
return setCarbonsEnabled(false);
}
/**
* Check if carbons are enabled on this connection.
*/
public boolean getCarbonsEnabled() {
return this.enabled_state;
}
/**
* Obtain a Carbon from a message, if available.
*
* @param msg Message object to check for carbons
*
* @return a Carbon if available, null otherwise.
*/
public static Carbon getCarbon(Message msg) {
Carbon cc = (Carbon)msg.getExtension("received", Carbon.NAMESPACE);
if (cc == null)
cc = (Carbon)msg.getExtension("sent", Carbon.NAMESPACE);
return cc;
}
/**
* Mark a message as "private", so it will not be carbon-copied.
*
* @param msg Message object to mark private
*/
public static void disableCarbons(Message msg) {
msg.addExtension(new Carbon.Private());
}
}