Add private messages feature

JitsiConference.js

     }
 };
 
+/**
+ * Send private text message to another participant of the conference
+ * @param message the text message.
+ */
+JitsiConference.prototype.sendPrivateTextMessage = function(id, message) {
+    if (this.room) {
+        this.room.sendPrivateMessage(id, message);
+    }
+};
+
 /**
  * Send presence command.
  * @param name {String} the name of the command.

JitsiConferenceEventManager.js

                 id, txt, ts);
         });
 
+    chatRoom.addListener(
+        XMPPEvents.PRIVATE_MESSAGE_RECEIVED,
+
+        // eslint-disable-next-line max-params
+        (jid, displayName, txt, myJid, ts) => {
+            const id = Strophe.getResourceFromJid(jid);
+
+            conference.eventEmitter.emit(
+                JitsiConferenceEvents.PRIVATE_MESSAGE_RECEIVED,
+                id, txt, ts);
+        });
+
     chatRoom.addListener(XMPPEvents.PRESENCE_STATUS,
         (jid, status) => {
             const id = Strophe.getResourceFromJid(jid);

JitsiConferenceEvents.js

  */
 export const MESSAGE_RECEIVED = 'conference.messageReceived';
 
+/**
+ * New private text message was received.
+ */
+export const PRIVATE_MESSAGE_RECEIVED = 'conference.privateMessageReceived';
+
 /**
  * Event fired when JVB sends notification about interrupted/restored user's
  * ICE connection status or we detect local problem with the video track.

modules/xmpp/ChatRoom.js

     }
 
     /**
-     *
+     * Send text message to the other participants in the conference
      * @param body
      * @param nickname
      */
         this.eventEmitter.emit(XMPPEvents.SENDING_CHAT_MESSAGE, body);
     }
 
+    /**
+     * Send private text message to another participant of the conference
+     * @param id id/muc resource of the receiver
+     * @param body
+     * @param nickname
+     */
+    sendPrivateMessage(id, body, nickname) {
+        const msg = $msg({ to: `${this.roomjid}/${id}`,
+            type: 'chat' });
+
+        msg.c('body', body).up();
+        if (nickname) {
+            msg.c('nick', { xmlns: 'http://jabber.org/protocol/nick' })
+                .t(nickname)
+                .up()
+                .up();
+        }
+
+        this.connection.send(msg);
+        this.eventEmitter.emit(XMPPEvents.SENDING_PRIVATE_CHAT_MESSAGE, body);
+    }
+
+
     /**
      *
      * @param subject
         }
 
         if (txt) {
-            this.eventEmitter.emit(XMPPEvents.MESSAGE_RECEIVED,
-                from, nick, txt, this.myroomjid, stamp);
+            if (type === 'chat') {
+                logger.log('privatechat', nick, txt);
+                this.eventEmitter.emit(XMPPEvents.PRIVATE_MESSAGE_RECEIVED,
+                        from, nick, txt, this.myroomjid, stamp);
+            }
+            if (type === 'groupchat') {
+                logger.log('chat', nick, txt);
+                this.eventEmitter.emit(XMPPEvents.MESSAGE_RECEIVED,
+                        from, nick, txt, this.myroomjid, stamp);
+            }
         }
     }
 

service/xmpp/XMPPEvents.js

     // received.
     MESSAGE_RECEIVED: 'xmpp.message_received',
 
+    // Designates an event indicating that a private XMPP message in the MUC was
+    // received.
+    PRIVATE_MESSAGE_RECEIVED: 'xmpp.private_message_received',
+
     // Designates an event indicating that the XMPP MUC was destroyed.
     MUC_DESTROYED: 'xmpp.muc_destroyed',
 
     // Designates an event indicating that we sent an XMPP message to the MUC.
     SENDING_CHAT_MESSAGE: 'xmpp.sending_chat_message',
 
+    // Designates an event indicating that we sent a private XMPP message to
+    // a specific user of the muc.
+    SENDING_PRIVATE_CHAT_MESSAGE: 'xmpp.sending_private_chat_message',
+
     /**
      * Event fired when we do not get our 'session-accept' acknowledged by
      * Jicofo. It most likely means that there is serious problem with our