Merge branch 'Semenchikus-XEP-0280' into develop (thanks to @aelmahmoudy)

app/src/main/java/com/xabber/android/data/SettingsManager.java

@@ -35,6 +35,7 @@ import com.xabber.android.service.XabberService;
 import com.xabber.android.ui.adapter.ComparatorByName;
 import com.xabber.android.ui.adapter.ComparatorByStatus;
 import com.xabber.androiddev.R;
+import com.xabber.xmpp.carbon.CarbonManager;
 
 import java.util.Comparator;
 
@@ -557,6 +558,11 @@ public class SettingsManager implements OnInitializedListener,
                 R.bool.connection_load_vcard_default);
     }
 
+    public static boolean connectionUseCarbons() {
+        return getBoolean(R.string.connection_use_carbons_key,
+                R.bool.connection_use_carbons_default);
+    }
+
     public static boolean connectionAdjustPriority() {
         return getBoolean(R.string.connection_adjust_priority_key,
                 R.bool.connection_adjust_priority_default);
@@ -750,6 +756,9 @@ public class SettingsManager implements OnInitializedListener,
         } else if (key.equals(Application.getInstance().getString(
                 R.string.connection_wifi_lock_key))) {
             NetworkManager.getInstance().onWifiLockSettingsChanged();
+        } else if (key.equals(Application.getInstance().getString(
+                R.string.connection_use_carbons_key))) {
+            CarbonManager.getInstance().onUseCarbonsSettingsChanged();
         } else if (key.equals(Application.getInstance().getString(
                 R.string.events_show_text_key))) {
             NotificationManager.getInstance().onMessageNotification();
@@ -762,4 +771,4 @@ public class SettingsManager implements OnInitializedListener,
         }
     }
 
-}
+}
\ No newline at end of file

app/src/main/java/com/xabber/android/data/message/AbstractChat.java

@@ -30,6 +30,7 @@ import com.xabber.android.data.extension.otr.SecurityLevel;
 import com.xabber.android.data.message.chat.ChatManager;
 import com.xabber.android.data.notification.NotificationManager;
 import com.xabber.xmpp.archive.SaveMode;
+import com.xabber.xmpp.carbon.CarbonManager;
 
 import org.jivesoftware.smack.packet.Message;
 import org.jivesoftware.smack.packet.Message.Type;
@@ -579,6 +580,8 @@ public abstract class AbstractChat extends BaseEntity {
                         message);
                 ReceiptManager.getInstance().updateOutgoingMessage(this,
                         message, messageItem);
+                CarbonManager.getInstance().updateOutgoingMessage(this,
+                        message, messageItem);
                 if (messageItem != intent)
                     message.addExtension(new DelayInformation(messageItem
                             .getTimestamp()));
@@ -688,4 +691,4 @@ public abstract class AbstractChat extends BaseEntity {
     public boolean isLastMessageIncoming() {
         return isLastMessageIncoming;
     }
-}
+}
\ No newline at end of file

app/src/main/java/com/xabber/android/data/message/MessageManager.java

@@ -41,6 +41,7 @@ import com.xabber.android.data.roster.RosterManager;
 import com.xabber.android.utils.StringUtils;
 import com.xabber.androiddev.R;
 import com.xabber.xmpp.address.Jid;
+import com.xabber.xmpp.carbon.CarbonManager.Direction;
 import com.xabber.xmpp.delay.Delay;
 
 import org.jivesoftware.smack.packet.Message;
@@ -499,6 +500,56 @@ public class MessageManager implements OnLoadListener, OnPacketListener, OnDisco
         }
     }
 
+    public void displayForwardedMessage(ConnectionItem connection, Message message, Direction direction) {
+
+        if (!(connection instanceof AccountItem))
+            return;
+        String account = ((AccountItem) connection).getAccount();
+        if (MessageArchiveManager.getInstance().isModificationsSucceed(account)
+                && Delay.isOfflineMessage(Jid.getServer(account), message)) {
+            // Ignore offline message if modification from server side message
+            // archive have been received.
+            return;
+        }
+
+        if (direction == Direction.sent) {
+            String companion = Jid.getBareAddress(message.getTo());
+            if (companion == null) {
+                return;
+            }
+            AbstractChat chat = getChat(account, companion);
+            if (chat == null) {
+                chat = createChat(account, companion);
+            }
+            String body = message.getBody();
+            if (body == null) {
+                return;
+            }
+            chat.newMessage(body);
+            return;
+        }
+
+        String companion = Jid.getBareAddress(message.getFrom());
+        boolean processed = false;
+        for (AbstractChat chat : chats.getNested(account).values()) {
+            if (chat.onPacket(companion, message)) {
+                processed = true;
+                break;
+            }
+        }
+        if (getChat(account, companion) != null) {
+            return;
+        }
+        if (processed) {
+            return;
+        }
+        final String body = message.getBody();
+        if (body == null) {
+            return;
+        }
+        createChat(account, companion).onPacket(companion, message);
+
+    }
     @Override
     public void onRosterReceived(AccountItem accountItem) {
         String account = accountItem.getAccount();
@@ -618,4 +669,4 @@ public class MessageManager implements OnLoadListener, OnPacketListener, OnDisco
         }
     }
 
-}
+}
\ No newline at end of file

app/src/main/java/com/xabber/xmpp/carbon/CarbonManager.java

+package com.xabber.xmpp.carbon;
+
+import org.jivesoftware.smack.Connection;
+import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.PacketListener;
+import org.jivesoftware.smack.XMPPConnection;
+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.smack.packet.PacketExtension;
+import org.jivesoftware.smackx.ServiceDiscoveryManager;
+
+import com.xabber.android.data.Application;
+import com.xabber.android.data.LogManager;
+import com.xabber.android.data.SettingsManager;
+import com.xabber.android.data.SettingsManager.SecurityOtrMode;
+import com.xabber.android.data.account.AccountItem;
+import com.xabber.android.data.connection.ConnectionItem;
+import com.xabber.android.data.connection.OnPacketListener;
+import com.xabber.android.data.extension.capability.OnServerInfoReceivedListener;
+import com.xabber.android.data.extension.capability.ServerInfoManager;
+import com.xabber.android.data.extension.otr.OTRManager;
+import com.xabber.android.data.extension.otr.SecurityLevel;
+import com.xabber.android.data.message.AbstractChat;
+import com.xabber.android.data.message.MessageItem;
+import com.xabber.android.data.message.MessageManager;
+
+/**
+ * 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, Semyon Baranov
+ */
+public class CarbonManager implements OnServerInfoReceivedListener, OnPacketListener
+{
+	private final static CarbonManager instance;
+	private Connection connection;
+    private volatile boolean enabled_state = false;
+    public static final String NAMESPACE = "urn:xmpp:carbons:2";
+    
+    static {
+		instance = new CarbonManager();
+		Application.getInstance().addManager(instance);
+		
+		Connection.addConnectionCreationListener(new ConnectionCreationListener() {
+					@Override
+					public void connectionCreated(final Connection connection) {
+						
+						if (!(connection instanceof XMPPConnection)) {
+							return;
+						}
+						
+				        ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection);
+				        if (sdm != null) {
+				            sdm.addFeature(NAMESPACE);
+				            sdm.addFeature(Forwarded.NAMESPACE);
+				        }  
+				        instance.connection = connection;					        
+					}
+				});
+	}
+
+	public static CarbonManager getInstance() {
+		
+		return instance;
+	}
+    
+    private CarbonManager() {
+    }
+    
+    private IQ carbonsEnabledIQ(final boolean new_state) {
+    	
+    	if (!checkConnected()) {
+    		return null;
+    	}
+        IQ setIQ = new IQ() {
+            public String getChildElementXML() {
+                return String.format("<%s xmlns='%s'/>", new_state ? "enable" : "disable", NAMESPACE);
+            }
+        };
+        setIQ.setType(IQ.Type.SET);        
+        setIQ.setFrom(connection.getUser());
+        return setIQ;
+    }
+    
+    private boolean checkConnected() {
+    	
+    	if (connection == null) {
+        	LogManager.exception(this, new Exception("connection is null"));
+            return false;
+        }
+    	if (!connection.isConnected()) {
+        	LogManager.exception(this, new Exception("not connected"));
+            return false;
+        }
+    	return true;
+	}
+
+	/**
+     * Returns true if XMPP Carbons are supported by the server.
+     * 
+     * @return true if supported
+     */
+    public boolean isSupportedByServer() {
+        
+    	if (!checkConnected()) {
+    		return false;
+    	}
+    	boolean isCarbonSupported = ServerInfoManager.getInstance().isProtocolSupported(connection.getUser(), NAMESPACE);
+    	return isCarbonSupported;
+    }
+    
+    /**
+     * 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) {
+        
+    	LogManager.d(this, "sendCarbonsEnabled " + String.valueOf(new_state));
+                
+        if (!checkConnected()) {
+    		return;
+    	}
+        
+        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);
+    }
+    
+    /**
+     * Helper method to enable carbons.
+     */
+    public void enableCarbons() {
+
+        sendCarbonsEnabled(true);
+    }
+    
+    /**
+     * Helper method to disable carbons.
+     */
+    public void disableCarbons() {
+    	
+    	sendCarbonsEnabled(false);
+    }
+    
+    /**
+     * Check if carbons are enabled on this connection.
+     */
+    public boolean getCarbonsEnabled() {
+    	
+        return enabled_state;
+    }
+    
+    /**
+     * 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 Private());
+    }
+    
+	@Override
+	public void onPacket(ConnectionItem connection, String bareAddress,
+			Packet packet) {
+		
+		if (!(connection instanceof AccountItem)) {
+			return;
+		}
+		if (!SettingsManager.connectionUseCarbons()) {
+			return;
+		}
+		final String user = packet.getFrom();
+		if (user == null)
+			return;
+		if (!(packet instanceof Message))
+			return;
+		final Message message = (Message) packet;	
+		if (!getCarbonsEnabled()) {
+			return;
+		}
+		PacketExtension carbonExtension = null;
+		Direction dir = null;
+		for (PacketExtension packetExtension : message.getExtensions()) {
+		    if (packetExtension instanceof Received) {
+		        carbonExtension = packetExtension;
+		        dir = Direction.received;
+		    } else if (packetExtension instanceof Sent) {
+		        carbonExtension = packetExtension;
+		        dir = Direction.sent;		    
+		    } else {
+		        continue;
+		    }
+		}
+	    if (carbonExtension == null) {
+            return;
+        }	 
+        Forwarded forwarded = null;
+	    if (dir == Direction.sent) {
+	        Sent carbon = (Sent) carbonExtension;
+	        forwarded = carbon.getForwarded();
+	    } else {
+	        Received carbon = (Received) carbonExtension;
+	        forwarded = carbon.getForwarded();
+	    }
+	    if (forwarded == null) {
+	        return;
+	    }
+        Message forwardedMsg = (Message) forwarded.getForwardedPacket();
+        MessageManager.getInstance().displayForwardedMessage(connection, forwardedMsg, dir);
+		
+	}
+    @Override
+	public void onServerInfoReceived(ConnectionItem connection) {
+		
+		if (isSupportedByServer()) { 
+			onUseCarbonsSettingsChanged();
+        }
+	}
+	
+	/**
+	 * Sends the new state of message carbons to the server
+	 * when this setting has been changed
+	 */
+	public void onUseCarbonsSettingsChanged() {
+		
+		sendCarbonsEnabled(SettingsManager.connectionUseCarbons());
+	}
+
+	/**
+	 * Update outgoing message before sending.
+	 * Marks the message as non-carbon-copied in the following cases:
+	 * - Message Carbons is enabled and OTR mode is enabled.
+	 * - Message Carbons is enabled and OTR security level != plain.
+	 * @param abstractChat 
+	 * @param message the <tt>Message</tt> to be sent
+	 * @param messageItem 
+	 */
+	public void updateOutgoingMessage(AbstractChat abstractChat, Message message, MessageItem messageItem) {
+
+		if (!SettingsManager.connectionUseCarbons()) {
+			return;
+		}
+		if (SettingsManager.securityOtrMode() == SecurityOtrMode.disabled) {
+			return;		
+		}
+		if (OTRManager.getInstance().getSecurityLevel(abstractChat.getAccount(),
+                        abstractChat.getUser()) != SecurityLevel.plain) {
+		    return;
+		}
+		message.addExtension(new Private());
+	}
+	
+	public enum Direction {
+	    sent, received
+	}
+}
\ No newline at end of file

app/src/main/java/com/xabber/xmpp/carbon/Forwarded.java

+package com.xabber.xmpp.carbon;
+
+import java.io.IOException;
+
+import org.jivesoftware.smack.packet.Packet;
+import org.jivesoftware.smackx.packet.DelayInfo;
+import org.xmlpull.v1.XmlSerializer;
+
+import com.xabber.xmpp.Container;
+import com.xabber.xmpp.PacketExtension;
+
+/**
+ * Packet extension for XEP-0297: Stanza Forwarding. This class implements
+ * the packet extension to parse
+ * forwarded messages from a packet. The extension
+ * <a href="http://xmpp.org/extensions/xep-0297.html">XEP-0297</a> is
+ * a prerequisite for XEP-0280 (Message Carbons).
+ *
+ * @author Semyon Baranov
+ */
+public class Forwarded extends PacketExtension implements Container {
+        
+    public static final String NAMESPACE = "urn:xmpp:forward:0";
+    public static final String ELEMENT_NAME = "forwarded";
+    
+    private DelayInfo delay;
+    private Packet forwardedPacket;
+    
+    public Forwarded() {        
+    }
+    
+    /**
+     * Creates a new Forwarded packet extension.
+     *
+     * @param delay an optional {@link DelayInfo} timestamp of the packet.
+     * @param fwdPacket the packet that is forwarded (required).
+     */
+    public Forwarded(DelayInfo delay, Packet fwdPacket) {
+        this();
+        this.delay = delay;
+        this.forwardedPacket = fwdPacket;
+    }
+    
+    @Override
+    public String getElementName() {
+        return ELEMENT_NAME;
+    }
+    
+    @Override
+    public String getNamespace() {
+        return NAMESPACE;
+    }
+    
+    @Override
+    public boolean isValid() {
+
+        return forwardedPacket != null;
+    }
+
+    @Override
+    public void serialize(XmlSerializer serializer) throws IOException {
+    }
+
+    @Override
+    public void serializeContent(XmlSerializer serializer) throws IOException {
+    }
+    
+    /**
+     * get the packet forwarded by this stanza.
+     *
+     * @return the {@link Packet} instance (typically a message) that was forwarded.
+     */
+    public Packet getForwardedPacket() {
+        return forwardedPacket;
+    }
+    
+    /**
+     * get the timestamp of the forwarded packet.
+     *
+     * @return the {@link DelayInfo} representing the time when the original packet was sent. May be null.
+     */
+    public DelayInfo getDelayInfo() {
+        return delay;
+    }
+}
\ No newline at end of file

app/src/main/java/com/xabber/xmpp/carbon/ForwardedProvider.java

+package com.xabber.xmpp.carbon;
+
+import java.io.IOException;
+
+import org.jivesoftware.smack.packet.Packet;
+import org.jivesoftware.smack.provider.PacketExtensionProvider;
+import org.jivesoftware.smack.util.PacketParserUtils;
+import org.jivesoftware.smackx.packet.DelayInfo;
+import org.jivesoftware.smackx.provider.DelayInfoProvider;
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+
+import com.xabber.android.data.LogManager;
+import com.xabber.xmpp.AbstractExtensionProvider;
+
+/**
+ * Packet extension for XEP-0297: Stanza Forwarding. This class implements
+ * a {@link PacketExtensionProvider} to parse forwarded messages from a packet. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0297.html">XEP-0297</a> 
+ * is a prerequisite for XEP-0280 (Message Carbons).
+ *
+ * <p>The {@link ForwardedProvider} must be registered in the
+ * <b>smack.providers</b> file for the element <b>forwarded</b> with
+ * namespace <b>urn:xmpp:forwarded:0</b></p> to be used.
+ *
+ * @author Semyon Baranov
+ */
+public class ForwardedProvider extends AbstractExtensionProvider<Forwarded> {
+
+    DelayInfoProvider dip = new DelayInfoProvider();
+    
+    @Override
+    protected Forwarded createInstance(XmlPullParser parser) {
+
+        return new Forwarded(null, null);
+    }
+        
+    @Override
+    public Forwarded parseExtension(XmlPullParser parser) throws Exception {
+        DelayInfoProvider dip = new DelayInfoProvider();
+        DelayInfo di = null;
+        Packet packet = null;
+
+        boolean done = false;
+        while (!done) {
+            int eventType = parser.next();
+            if (eventType == XmlPullParser.START_TAG) {
+                if (parser.getName().equals("delay"))
+                    di = (DelayInfo)dip.parseExtension(parser);
+                else if (parser.getName().equals("message"))
+                    packet = PacketParserUtils.parseMessage(parser);
+                else throw new Exception("Unsupported forwarded packet type: " + parser.getName());
+            }
+            else if (eventType == XmlPullParser.END_TAG && parser.getName().equals(Forwarded.ELEMENT_NAME))
+                done = true;
+        }
+        if (packet == null)
+            throw new Exception("forwarded extension must contain a packet");
+        return new Forwarded(di, packet);
+    }
+}

app/src/main/java/com/xabber/xmpp/carbon/Private.java

+package com.xabber.xmpp.carbon;
+
+import java.io.IOException;
+
+import org.xmlpull.v1.XmlSerializer;
+
+import com.xabber.xmpp.PacketExtension;
+
+/**
+ * Packet extension for XEP-0280: Message Carbons. This class implements
+ * the packet extension to exclude a <message/> from being forwarded 
+ * to other Carbons-enabled resources. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0280.html">XEP-0280</a> 
+ * is meant to synchronize a message flow to multiple presences of a user.
+ *
+ * @author Semyon Baranov
+ */
+public class Private extends PacketExtension {
+    
+    public static final String ELEMENT_NAME = "private";
+    public static final String NAMESPACE = "urn:xmpp:carbons:2";
+    
+    @Override
+    public String getElementName() {
+        return ELEMENT_NAME;
+    }
+
+    @Override
+    public String getNamespace() {
+        return NAMESPACE;
+    }
+
+    @Override
+    public void serializeContent(XmlSerializer serializer) throws IOException {
+    }
+
+    @Override
+    public boolean isValid() {
+        return true;
+    }
+
+}

app/src/main/java/com/xabber/xmpp/carbon/PrivateProvider.java

+package com.xabber.xmpp.carbon;
+
+import org.jivesoftware.smack.provider.PacketExtensionProvider;
+import org.xmlpull.v1.XmlPullParser;
+
+import com.xabber.xmpp.AbstractExtensionProvider;
+
+/**
+ * Packet extension for XEP-0280: Message Carbons. This class implements
+ * a {@link PacketExtensionProvider} to exclude a <message/> from being 
+ * forwarded to other Carbons-enabled resources. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0280.html">XEP-0280</a> 
+ * is meant to synchronize a message flow to multiple presences of a user.
+ *
+ * @author Semyon Baranov
+ */
+public class PrivateProvider  extends AbstractExtensionProvider<Private> {
+
+    @Override
+    protected Private createInstance(XmlPullParser parser) {
+        return new Private();
+    }
+}

app/src/main/java/com/xabber/xmpp/carbon/Received.java

+package com.xabber.xmpp.carbon;
+
+import java.io.IOException;
+
+import org.xmlpull.v1.XmlSerializer;
+
+import com.xabber.xmpp.PacketExtension;
+
+/**
+ * Packet extension for XEP-0280: Message Carbons. This class implements
+ * the packet extension to parse a received message from a packet. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0280.html">XEP-0280</a> 
+ * is meant to synchronize a message flow to multiple presences of a user.
+ *
+ * @author Semyon Baranov
+ */
+public class Received extends PacketExtension {
+    public static final String ELEMENT_NAME = "received";
+    public static final String NAMESPACE = "urn:xmpp:carbons:2";
+    private Forwarded fwd;
+    
+    public Received() {
+    }
+
+    @Override
+    public String getElementName() {
+        return ELEMENT_NAME;
+    }
+
+    @Override
+    public String getNamespace() {
+        return NAMESPACE;
+    }
+
+    @Override
+    public void serializeContent(XmlSerializer serializer) throws IOException {   
+    }
+
+    @Override
+    public boolean isValid() {
+        return fwd != null;
+    }
+    
+    /**
+     * Gets the forwarded packet or null if the forwarded has not been set.
+     *
+     * @return the {@link Forwarded} message contained in this Carbon.
+     */
+    public Forwarded getForwarded() {
+        
+        return fwd;
+    }
+    
+    /**
+     * Sets the forwarded packet.
+     * @param fwd - the {@link Forwarded} message contained in this Carbon.
+     */
+    public void setForwarded(Forwarded fwd) {
+        
+        this.fwd = fwd;
+    }
+}

app/src/main/java/com/xabber/xmpp/carbon/ReceivedProvider.java

+package com.xabber.xmpp.carbon;
+
+import org.jivesoftware.smack.provider.PacketExtensionProvider;
+import org.jivesoftware.smack.util.PacketParserUtils;
+import org.xmlpull.v1.XmlPullParser;
+
+import com.xabber.android.data.LogManager;
+import com.xabber.xmpp.AbstractExtensionProvider;
+
+/**
+ * Packet extension for XEP-0280: Message Carbons. This class implements
+ * a {@link PacketExtensionProvider} to parse a received message from a packet. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0280.html">XEP-0280</a> 
+ * is meant to synchronize a message flow to multiple presences of a user.
+ *
+ * @author Semyon Baranov
+ */
+public class ReceivedProvider extends AbstractExtensionProvider<Received> {
+    @Override
+    protected Received createInstance(XmlPullParser parser) {
+        
+        return new Received();
+    }
+    
+    @Override
+    protected boolean parseInner(XmlPullParser parser, Received instance)
+            throws Exception {
+        
+        Forwarded forwarded = null;
+        if (parser.getName().equals(Forwarded.ELEMENT_NAME)) {
+            try {
+                forwarded = (Forwarded) PacketParserUtils.parsePacketExtension(Forwarded.ELEMENT_NAME, Forwarded.NAMESPACE, parser);
+            } catch (Exception e) {
+                LogManager.exception(this, e);
+            }
+        } 
+        
+        if (forwarded == null) {
+            LogManager.exception(this, new Exception("received extension must contain a forwarded extension"));
+            return false;
+        }
+        instance.setForwarded(forwarded);
+        return true;
+    }
+}

app/src/main/java/com/xabber/xmpp/carbon/Sent.java

+package com.xabber.xmpp.carbon;
+
+import java.io.IOException;
+
+import org.xmlpull.v1.XmlSerializer;
+
+import com.xabber.xmpp.PacketExtension;
+
+/**
+ * Packet extension for XEP-0280: Message Carbons. This class implements
+ * the packet extension to parse a sent message from a packet. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0280.html">XEP-0280</a> 
+ * is meant to synchronize a message flow to multiple presences of a user.
+ *
+ * @author Semyon Baranov
+ */
+public class Sent extends PacketExtension {
+    public static final String ELEMENT_NAME = "sent";
+    public static final String NAMESPACE = "urn:xmpp:carbons:2";
+    private Forwarded fwd;
+        
+    public Sent() {
+        
+    }
+
+    @Override
+    public String getElementName() {
+        return ELEMENT_NAME;
+    }
+
+    @Override
+    public String getNamespace() {
+        return NAMESPACE;
+    }
+
+    @Override
+    public void serializeContent(XmlSerializer serializer) throws IOException { 
+    }
+
+    @Override
+    public boolean isValid() {
+        return fwd != null;
+    }
+    
+    /**
+     * Gets the forwarded packet or null if the forwarded has not been set.
+     *
+     * @return the {@link Forwarded} message contained in this Carbon.
+     */
+    public Forwarded getForwarded() {
+        
+        return fwd;
+    }
+    
+    /**
+     * Sets the forwarded packet.
+     * @param fwd - the {@link Forwarded} message contained in this Carbon.
+     */
+    public void setForwarded(Forwarded fwd) {
+        
+        this.fwd = fwd;
+    }
+}

app/src/main/java/com/xabber/xmpp/carbon/SentProvider.java

+package com.xabber.xmpp.carbon;
+
+import org.jivesoftware.smack.provider.PacketExtensionProvider;
+import org.jivesoftware.smack.util.PacketParserUtils;
+import org.xmlpull.v1.XmlPullParser;
+
+import com.xabber.android.data.LogManager;
+import com.xabber.xmpp.AbstractExtensionProvider;
+
+/**
+ * Packet extension for XEP-0280: Message Carbons. This class implements
+ * a {@link PacketExtensionProvider} to parse a sent message from a packet. 
+ * The extension <a href="http://xmpp.org/extensions/xep-0280.html">XEP-0280</a> 
+ * is meant to synchronize a message flow to multiple presences of a user.
+ *
+ * @author Semyon Baranov
+ */
+public class SentProvider extends AbstractExtensionProvider<Sent> {
+
+    @Override
+    protected Sent createInstance(XmlPullParser parser) {
+        
+        return new Sent();
+    }
+    
+    @Override
+    protected boolean parseInner(XmlPullParser parser, Sent instance)
+            throws Exception {
+        
+        Forwarded forwarded = null;        
+        
+        if (parser.getName().equals(Forwarded.ELEMENT_NAME)) {
+            try {
+                forwarded = (Forwarded) PacketParserUtils.parsePacketExtension(Forwarded.ELEMENT_NAME, Forwarded.NAMESPACE, parser);
+            } catch (Exception e) {
+                LogManager.exception(this, e);
+            }
+        } 
+        
+        if (forwarded == null) {
+            LogManager.exception(this, new Exception("sent extension must contain a forwarded extension"));
+            return false;
+        }
+        instance.setForwarded(forwarded);
+        return true;
+    }
+}

app/src/main/res/raw/smack.providers

@@ -247,4 +247,29 @@
         <className>com.xabber.xmpp.attention.AttentionProvider</className>
     </extensionProvider>
 
+	<!-- Message Carbons -->
+    <extensionProvider>
+        <elementName>sent</elementName>
+        <namespace>urn:xmpp:carbons:2</namespace>
+        <className>com.xabber.xmpp.carbon.SentProvider</className>
+    </extensionProvider>
+
+    <extensionProvider>
+        <elementName>received</elementName>
+        <namespace>urn:xmpp:carbons:2</namespace>
+        <className>com.xabber.xmpp.carbon.ReceivedProvider</className>
+    </extensionProvider>
+    
+    <extensionProvider>
+        <elementName>private</elementName>
+        <namespace>urn:xmpp:carbons:2</namespace>
+        <className>com.xabber.xmpp.carbon.PrivateProvider</className>
+    </extensionProvider>
+    
+    <!-- Message Forwarding -->
+    <extensionProvider>
+        <elementName>forwarded</elementName>
+        <namespace>urn:xmpp:forward:0</namespace>
+        <className>com.xabber.xmpp.carbon.ForwardedProvider</className>
+    </extensionProvider>
 </smackProviders>
\ No newline at end of file

app/src/main/res/values-ru/preference_editor.xml

@@ -147,6 +147,7 @@
     <string name="chats_attention">Привлечение внимания\nОтзываться на запросы привлечения внимания</string>
     <string name="chats_attention_sound">Звук привлечения внимания\nВыберите мелодию звонка</string>
     <string name="connection_load_vcard">Загружать vCard\nЗагружать и обновлять персональную информацию и аватары контактов. Отключение поможет сэкономить трафик.</string>
+	<string name="connection_use_carbons">Сообщения carbons\nПринимать сообщения других сессий Вашей учетной записи. Отключение поможет сэкономить трафик.</string>
     <string name="events_phrases">Ключевые фразы\nНастройки уведомлений о сообщениях содержащих ключевые фразы</string>
     <!-- http://dl.dropbox.com/u/1029995/com.xabber.android/preference_editor_security_remove.png -->
     <string name="security_clear_certificate_warning">Вы действительно хотите удалить все игнорируемые сертификаты?</string>

app/src/main/res/values/preference_editor.xml

@@ -147,6 +147,7 @@
     <string name="chats_attention">Attention\nReact for the incoming attention requests</string>
     <string name="chats_attention_sound">Attention sound\nChoose ring-tone</string>
     <string name="connection_load_vcard">Load vCard\nLoad and update contact\'s personal info and avatar. Disable to reduce traffic usage.</string>
+	<string name="connection_use_carbons">Carbon-copied mode\nWill share the sessions for the same account on this client. Disable to reduce traffic usage.</string>
     <string name="events_phrases">Key phrases\nCustom sound notifications about messages with preset phrases</string>
     <!-- http://dl.dropbox.com/u/1029995/com.xabber.android/preference_editor_security_remove.png -->
     <string name="security_clear_certificate_warning">Do you really want to remove all the ignored certificates?</string>

app/src/main/res/values/preferences.xml

@@ -50,6 +50,7 @@
         <item>com.xabber.android.data.extension.capability.ServerInfoManager</item>
         <item>com.xabber.android.data.extension.time.TimeManager</item>
         <item>com.xabber.android.data.extension.attention.AttentionManager</item>
+        <item>com.xabber.xmpp.carbon.CarbonManager</item>
     </string-array>
 
     <string-array name="contact_managers">
@@ -127,10 +128,10 @@
 
     <string name="contacts_show_offline_key">contacts_show_offline</string>
     <bool name="contacts_show_offline_default">false</bool>
-            
+
     <string name="contacts_show_groups_key">contacts_show_groups</string>
     <bool name="contacts_show_groups_default">true</bool>
-            
+
     <string name="contacts_show_accounts_key">contacts_show_accounts</string>
     <bool name="contacts_show_accounts_default">true</bool>
 
@@ -142,7 +143,7 @@
 
     <string name="contacts_show_empty_groups_key">contacts_show_empty_groups</string>
     <bool name="contacts_show_empty_groups_default">false</bool>
-        
+
     <string name="contacts_order_key">contacts_order</string>
     <string name="contacts_order_status_value">status</string>
     <string name="contacts_order_alphabet_value">alphabet</string>
@@ -198,7 +199,7 @@
 
     <string name="events_visible_chat_key">events_visible_chat</string>
     <bool name="events_visible_chat_default">false</bool>
-    
+
     <string name="events_first_only_key">events_first_only</string>
     <bool name="events_first_only_default">false</bool>
 
@@ -362,6 +363,9 @@
     <string name="connection_load_vcard_key">connection_load_vcard</string>
     <bool name="connection_load_vcard_default">true</bool>
 
+    <string name="connection_use_carbons_key">connection_use_carbons</string>
+    <bool name="connection_use_carbons_default">true</bool>
+
 <!-- preference_cache -->
     <string name="cache_clear_key">cache_clear</string>
 

app/src/main/res/xml/preference_connection.xml

@@ -34,6 +34,11 @@
         android:key="@string/connection_load_vcard_key"
         android:defaultValue="@bool/connection_load_vcard_default"
         />
+    <CheckBoxPreference
+        android:title="@string/connection_use_carbons"
+        android:key="@string/connection_use_carbons_key"
+        android:defaultValue="@bool/connection_use_carbons_default"
+        />
     <PreferenceCategory
         android:title="@string/connection_priority"
         >