Implements audio and visual chat notifications. Closes issue #7. Implements audio notifications for people joining and leaving. Closes issue #37.

app.js

         container = document.createElement('span');
         container.className = 'videocontainer';
         remotes.appendChild(container);
+        console.log("PLAY USER JOINEDDDDDDDD");
+        Util.playSoundNotification('userJoined');
     }
     var vid = document.createElement('video');
     var id = 'remoteVideo_' + sid + '_' + data.stream.id;
             if (pick) {
                  if (pick.src === localVideoSrc)
                  isLocalVideo = true;
-                 
+
                  updateLargeVideo(pick.src, isLocalVideo, pick.volume);
             }
         }
         $('#' + id).parent().remove();
+        Util.playSoundNotification('userLeft');
         resizeThumbnails();
     };
     sel.click(
     }
 }
 
-function resizeLarge() {
-    resizeChat();
+var resizeLarge = function () {
+    Chat.resizeChat();
     var availableHeight = window.innerHeight;
     var chatspaceWidth = $('#chatspace').is(":visible")
                             ? $('#chatspace').width()
     }
 
     resizeThumbnails();
-}
+};
 
 function resizeThumbnails() {
     // Calculate the available height, which is the inner window height minus 39px for the header
     $('#remoteVideos>span').height(availableHeight);
 }
 
-function resizeChat() {
-    var availableHeight = window.innerHeight;
-    var availableWidth = window.innerWidth;
-
-    var chatWidth = 200;
-    if (availableWidth*0.2 < 200)
-        chatWidth = availableWidth*0.2;
-
-    $('#chatspace').width(chatWidth);
-    $('#chatspace').height(availableHeight - 40);
-
-    resizeChatConversation();
-}
-
-function resizeChatConversation() {
-    var usermsgStyleHeight = document.getElementById("usermsg").style.height;
-    var usermsgHeight = usermsgStyleHeight.substring(0, usermsgStyleHeight.indexOf('px'));
-
-    $('#chatconversation').width($('#chatspace').width() - 10);
-    $('#chatconversation').height(window.innerHeight - 50 - parseInt(usermsgHeight));
-}
-
 $(document).ready(function () {
-    var storedDisplayName = window.localStorage.displayname;
-    if (storedDisplayName) {
-        nickname = storedDisplayName;
-
-        setChatConversationMode(true);
-    }
-
-    $('#nickinput').keydown(function(event) {
-        if (event.keyCode == 13) {
-            event.preventDefault();
-            var val = this.value;
-            this.value = '';
-            if (!nickname) {
-                nickname = val;
-                window.localStorage.displayname = nickname;
-
-                connection.emuc.addDisplayNameToPresence(nickname);
-                connection.emuc.sendPresence();
-
-                setChatConversationMode(true);
-
-                return;
-            }
-        }
-    });
-
-    $('#usermsg').keydown(function(event) {
-        if (event.keyCode == 13) {
-            event.preventDefault();
-            var message = this.value;
-            $('#usermsg').val('').trigger('autosize.resize');
-            this.focus();
-            connection.emuc.sendMessage(message, nickname);
-        }
-    });
-
-    var onTextAreaResize = function() {
-        resizeChatConversation();
-        scrollChatToBottom();
-    };
-    $('#usermsg').autosize({callback: onTextAreaResize});
+    Chat.init();
 
     // Set the defaults for prompt dialogs.
     jQuery.prompt.setDefaults({persistent: false});
     return false;
 }
 
-/*
- * Appends the given message to the chat conversation.
- */
-function updateChatConversation(nick, message)
-{
-    var divClassName = '';
-    if (nickname == nick)
-        divClassName = "localuser";
-    else
-        divClassName = "remoteuser";
-
-    //replace links and smileys
-    message = processReplacements(message);
-
-    $('#chatconversation').append('<div class="' + divClassName + '"><b>' + nick + ': </b>' + message + '</div>');
-    $('#chatconversation').animate({ scrollTop: $('#chatconversation')[0].scrollHeight}, 1000);
-}
-
 /*
  * Changes the style class of the element given by id.
  */
     buttonClick("#lockIcon", "fa fa-unlock fa-lg fa fa-lock fa-lg");
 }
 
-/*
- * Opens / closes the chat area.
- */
-function openChat() {
-    var chatspace = $('#chatspace');
-    var videospace = $('#videospace');
-
-    var onShow = function () {
-        resizeLarge();
-        $('#chatspace').show("slide", { direction: "right", duration: 500});
-    };
-    var onHide = function () {
-        $('#chatspace').hide("slide", { direction: "right", duration: 500});
-        resizeLarge();
-    };
-
-    if (chatspace.css("display") == 'block') {
-        videospace.animate({right: 0}, {queue: false, duration: 500, progress: onHide});
-    }
-    else {
-        videospace.animate({right: chatspace.width()},
-                           {queue: false,
-                            duration: 500,
-                            progress: onShow,
-                            complete: function() {
-                                scrollChatToBottom();
-                            }
-                           });
-    }
-
-    // Request the focus in the nickname field or the chat input field.
-    if ($('#nickname').css('visibility') == 'visible')
-        $('#nickinput').focus();
-    else {
-        $('#usermsg').focus();
-    }
-}
-
 /*
  * Shows the call main toolbar.
  */
     return container;
 }
 
-/*
+/**
  * Creates the element indicating the focus of the conference.
  */
 function createFocusIndicatorElement(parentElement) {
     parentElement.appendChild(focusIndicator);
 }
 
-function scrollChatToBottom() {
-    setTimeout(function() {
-        $('#chatconversation').scrollTop($('#chatconversation')[0].scrollHeight);
-    }, 5);
-}
-
-/*
+/**
  * Toggles the application in and out of full screen mode 
  * (a.k.a. presentation mode in Chrome).
  */
 }
 
 /**
- *
+ * Shows the display name for the given video.
  */
 function showDisplayName(videoSpanId, displayName) {
     var nameSpan = $('#' + videoSpanId + '>span.displayname');
                         connection.emuc.addDisplayNameToPresence(nickname);
                         connection.emuc.sendPresence();
 
-                        setChatConversationMode(true);
+                        Chat.setChatConversationMode(true);
                     }
 
                     if (!$('#localDisplayName').is(":visible")) {
     editButton.innerHTML = '<i class="fa fa-pencil"></i>';
 
     return editButton;
-}
-
-function setChatConversationMode(isConversationMode) {
-    if (isConversationMode) {
-        $('#nickname').css({visibility:"hidden"});
-        $('#chatconversation').css({visibility:'visible'});
-        $('#usermsg').css({visibility:'visible'});
-        $('#usermsg').focus();
-    }
-}
+}

chat.js

+/**
+ * Chat related user interface.
+ */
+var Chat = (function (my) {
+    var notificationInterval = false;
+    var unreadMessages = 0;
+
+    /**
+     * Initializes chat related interface.
+     */
+    my.init = function () {
+        var storedDisplayName = window.localStorage.displayname;
+        if (storedDisplayName) {
+            nickname = storedDisplayName;
+
+            Chat.setChatConversationMode(true);
+        }
+
+        $('#nickinput').keydown(function(event) {
+            if (event.keyCode == 13) {
+                event.preventDefault();
+                var val = this.value;
+                this.value = '';
+                if (!nickname) {
+                    nickname = val;
+                    window.localStorage.displayname = nickname;
+
+                    connection.emuc.addDisplayNameToPresence(nickname);
+                    connection.emuc.sendPresence();
+
+                    Chat.setChatConversationMode(true);
+
+                    return;
+                }
+            }
+        });
+
+        $('#usermsg').keydown(function(event) {
+            if (event.keyCode == 13) {
+                event.preventDefault();
+                var message = this.value;
+                $('#usermsg').val('').trigger('autosize.resize');
+                this.focus();
+                connection.emuc.sendMessage(message, nickname);
+            }
+        });
+
+        var onTextAreaResize = function() {
+            resizeChatConversation();
+            scrollChatToBottom();
+        };
+        $('#usermsg').autosize({callback: onTextAreaResize});
+
+        $("#chatspace").bind("shown",
+            function() {
+                unreadMessages = 0;
+                setVisualNotification(false);
+            });
+    };
+
+    /**
+     * Appends the given message to the chat conversation.
+     */
+    my.updateChatConversation = function (nick, message) {
+        var divClassName = '';
+
+        if (nickname == nick) {
+            divClassName = "localuser";
+        }
+        else {
+            divClassName = "remoteuser";
+
+            if (!$('#chatspace').is(":visible")) {
+                unreadMessages++;
+                Util.playSoundNotification('chatNotification');
+                setVisualNotification(true);
+            }
+        }
+
+        //replace links and smileys
+        message = processReplacements(message);
+
+        $('#chatconversation').append('<div class="' + divClassName + '"><b>'
+                                        + nick + ': </b>' + message + '</div>');
+        $('#chatconversation').animate(
+                { scrollTop: $('#chatconversation')[0].scrollHeight}, 1000);
+    };
+
+    /**
+     * Opens / closes the chat area.
+     */
+    my.toggleChat = function () {
+        var chatspace = $('#chatspace');
+        var videospace = $('#videospace');
+
+        var onShow = function () {
+            resizeLarge();
+            $('#chatspace').show("slide", { direction: "right", duration: 500});
+        };
+        var onHide = function () {
+            $('#chatspace').hide("slide", { direction: "right", duration: 500});
+            resizeLarge();
+        };
+
+        if (chatspace.is(":visible")) {
+            videospace.animate( {right: 0},
+                                {queue: false,
+                                duration: 500,
+                                progress: onHide});
+        }
+        else {
+            videospace.animate({right: chatspace.width()},
+                               {queue: false,
+                                duration: 500,
+                                progress: onShow,
+                                complete: function() {
+                                    scrollChatToBottom();
+                                    chatspace.trigger('shown');
+                                }
+                               });
+        }
+
+        // Request the focus in the nickname field or the chat input field.
+        if ($('#nickname').css('visibility') == 'visible')
+            $('#nickinput').focus();
+        else {
+            $('#usermsg').focus();
+        }
+    };
+
+    /**
+     * Sets the chat conversation mode.
+     */
+    my.setChatConversationMode = function (isConversationMode) {
+        if (isConversationMode) {
+            $('#nickname').css({visibility:"hidden"});
+            $('#chatconversation').css({visibility:'visible'});
+            $('#usermsg').css({visibility:'visible'});
+            $('#usermsg').focus();
+        }
+    };
+
+    /**
+     * Resizes the chat area.
+     */
+    my.resizeChat = function () {
+        var availableHeight = window.innerHeight;
+        var availableWidth = window.innerWidth;
+
+        var chatWidth = 200;
+        if (availableWidth*0.2 < 200)
+            chatWidth = availableWidth*0.2;
+
+        $('#chatspace').width(chatWidth);
+        $('#chatspace').height(availableHeight - 40);
+
+        resizeChatConversation();
+    };
+
+    /**
+     * Resizes the chat conversation.
+     */
+    function resizeChatConversation() {
+        var usermsgStyleHeight = document.getElementById("usermsg").style.height;
+        var usermsgHeight = usermsgStyleHeight
+            .substring(0, usermsgStyleHeight.indexOf('px'));
+
+        $('#chatconversation').width($('#chatspace').width() - 10);
+        $('#chatconversation')
+            .height(window.innerHeight - 50 - parseInt(usermsgHeight));
+    };
+
+    /**
+     * Shows/hides a visual notification, indicating that a message has arrived.
+     */
+    function setVisualNotification(show) {
+        var unreadMsgElement = document.getElementById('unreadMessages');
+
+        if (unreadMessages) {
+            unreadMsgElement.innerHTML = unreadMessages.toString();
+
+            var chatButtonElement
+                = document.getElementById('chat').parentNode;
+            var leftIndent = (Util.getTextWidth(chatButtonElement)
+                                - Util.getTextWidth(unreadMsgElement) - 5)/2;
+            var topIndent = (Util.getTextHeight(chatButtonElement)
+                                - Util.getTextHeight(unreadMsgElement))/2 - 2;
+
+            unreadMsgElement.setAttribute(
+                    'style',
+                    'top:' + Util.toInteger(topIndent)
+                     + '; left:' + Util.toInteger(leftIndent) +';');
+        }
+        else
+            unreadMsgElement.innerHTML = '';
+
+        var glower = $('#chat');
+
+        if (show && !notificationInterval) {
+            notificationInterval = window.setInterval(function() {
+                glower.toggleClass('active');
+            }, 800);
+        }
+        else if (!show && notificationInterval) {
+            window.clearInterval(notificationInterval);
+            notificationInterval = false;
+            glower.removeClass('active');
+        }
+    }
+
+    /**
+     * Scrolls chat to the bottom.
+     */
+    function scrollChatToBottom() {
+        setTimeout(function() {
+            $('#chatconversation').scrollTop(
+                    $('#chatconversation')[0].scrollHeight);
+        }, 5);
+    }
+
+    return my;
+}(Chat || {}));

css/main.css

     height:100%;
     color: #424242;
     font-family:'Helvetica Neue', Helvetica, sans-serif;
-	font-weight: 400;
+    font-weight: 400;
     background: #e9e9e9;
     overflow-x: hidden;
 }
 }
 
 #left {
-	display:block;
+    display:block;
     position: absolute;
-	left: 0px;
+    left: 0px;
     top: 0px;
     width: 100px;
     height: 39px;
-	background-image:url(../images/left1.png);
-	background-repeat:no-repeat;
-	margin: 0;
-	padding: 0;
+    background-image:url(../images/left1.png);
+    background-repeat:no-repeat;
+    margin: 0;
+    padding: 0;
 }
 
 #leftlogo {
     visibility: hidden;
 }
 
+.toolbar_span {
+    display: inline-block;
+    position: relative;
+}
+
 .button {
     display: inline-block;
     position: relative;
     font-size: 11pt;
     text-align: center;
     text-shadow: 0px 1px 0px rgba(255,255,255,.3), 0px -1px 0px rgba(0,0,0,.7);
+    z-index: 1;
+}
+
+.toolbar_span>span {
+    display: inline-block;
+    position: absolute;
+    font-size: 7pt;
+    color: #ffffff;
+    text-align:center;
+    cursor: pointer;
+}
+
+#chat {
+    font-size:1.65em;
+    -webkit-transition: all .5s ease-in-out;;
+       -moz-transition: all .5s ease-in-out;;
+            transition: all .5s ease-in-out;;
+}
+
+#chat.active {
+    -webkit-text-shadow: 0 0 10px #ffffff;
+    -moz-text-shadow: 0 0 10px #ffffff;
+    text-shadow: 0 0 10px #ffffff;
+    -webkit-transform: scale(1.1);
 }
 
 a.button:hover {
 }
 
 #right {
-	display:block;
+    display:block;
     position:absolute;
     right: 0px;
     top: 0px;
-	background-image:url(../images/right1.png);
-	background-repeat:no-repeat;
-	margin:0;
-	padding:0;
-	width:100px;
+    background-image:url(../images/right1.png);
+    background-repeat:no-repeat;
+    margin:0;
+    padding:0;
+    width:100px;
     height:39px;
 }
 

etherpad.js

 
             if (!name) {
                 // In case we're the focus we generate the name.
-                etherpadName = Math.random().toString(36).substring(7) + '_' + (new Date().getTime()).toString();
+                etherpadName = Math.random().toString(36).substring(7)
+                                + '_' + (new Date().getTime()).toString();
                 shareEtherpad();
             }
             else
         button.appendChild(buttonImage);
 
         var toolbar = document.getElementById('toolbar');
-        toolbar.insertBefore(button, toolbar.childNodes[toolbar.childNodes.length - 4]);
+        toolbar.insertBefore(button,
+                toolbar.childNodes[toolbar.childNodes.length - 4]);
         toolbar.insertBefore(separator, button);
     }
 

index.html

     <script src="muc.js?v=6"></script><!-- simple MUC library -->
     <script src="estos_log.js?v=2"></script><!-- simple stanza logger -->
     <script src="app.js?v=20"></script><!-- application logic -->
+    <script src="chat.js?v=1"></script><!-- chat logic -->
+    <script src="util.js?v=1"></script><!-- utility functions -->
     <script src="etherpad.js?v=2"></script><!-- etherpad plugin -->
     <script src="smileys.js?v=1"></script><!-- smiley images -->
     <script src="replacement.js?v=5"></script><!-- link and smiley replacement -->
         <a href="http://jitsi.org" target="_blank"><div id="leftlogo"></div></a>
         <a href="http://www.estos.com/" target="_blank"><div id="rightlogo"></div></a>
         <span id="toolbar">
-            <a class="button" onclick='buttonClick("#mute", "fa fa-microphone fa-lg fa fa-microphone-slash fa-lg");toggleAudio();'><i id="mute" title="Mute / unmute" class="fa fa-microphone fa-lg"></i></a>
+            <a class="button" onclick='buttonClick("#mute", "fa fa-microphone fa-lg fa fa-microphone-slash fa-lg");toggleAudio();'>
+                <i id="mute" title="Mute / unmute" class="fa fa-microphone fa-lg"></i></a>
             <div class="header_button_separator"></div>
-            <a class="button" onclick='buttonClick("#video", "fa fa-video-camera fa-lg fa fa-video-camera no-fa-video-camera fa-lg");toggleVideo();'><i id="video" title="Start / stop camera" class="fa fa-video-camera fa-lg"></i></a>
+            <a class="button" onclick='buttonClick("#video", "fa fa-video-camera fa-lg fa fa-video-camera no-fa-video-camera fa-lg");toggleVideo();'>
+                <i id="video" title="Start / stop camera" class="fa fa-video-camera fa-lg"></i></a>
             <div class="header_button_separator"></div>
             <a class="button" onclick="openLockDialog();"><i id="lockIcon" title="Lock/unlock room" class="fa fa-unlock fa-lg"></i></a>
             <div class="header_button_separator"></div>
             <a class="button" onclick="openLinkDialog();"><i title="Invite others" class="fa fa-link fa-lg"></i></a>
             <div class="header_button_separator"></div>
-            <a class="button" onclick='openChat();'><i id="chat" title="Open chat" class="fa fa-comments fa-lg"></i></a>
+            <span class="toolbar_span">
+                <a class="button" onclick='Chat.toggleChat();'><i id="chat" title="Open chat" class="fa fa-comments-o fa-lg"></i></a>
+                <span id="unreadMessages"></span>
+            </span>
             <div class="header_button_separator"></div>
-            <a class="button" onclick='openPreziDialog();'><i title="Share prezi" class="fa fa-desktop fa-lg"></i></a>
+            <a class="button" onclick='openPreziDialog();'><i title="Share prezi" class="fa fa-picture-o fa-lg"></i></a>
             <div class="header_button_separator"></div>
             <a class="button" onclick='toggleFullScreen();'><i title="Enter / Exit Full Screen" class="fa fa-arrows-alt fa-lg"></i></a>
         </span>
                 <video id="localVideo" autoplay oncontextmenu="return false;" muted></video>
                 <span class="focusindicator"></span>
             </span>
+            <audio id="userJoined" src="sounds/joined.wav" preload="auto"></audio>
+            <audio id="userLeft" src="sounds/left.wav" preload="auto"></audio>
         </div>
     </div>
     <div id="chatspace">
                 <input type='text' id="nickinput" placeholder='Choose a nickname' autofocus>
             </form>
         </div>
-        
+
         <!--div><i class="fa fa-comments">&nbsp;</i><span class='nick'></span>:&nbsp;<span class='chattext'></span></div-->
         <div id="chatconversation"></div>
+        <audio id="chatNotification" src="sounds/incomingMessage.wav" preload="auto"></audio>
         <textarea id="usermsg" placeholder='Enter text...' autofocus></textarea>
     </div>
     <a id="downloadlog" onclick='dump(event.target);'><i title="Download support information" class="fa fa-cloud-download"></i></a>

muc.js

         if (txt) {
             console.log('chat', nick, txt);
 
-            updateChatConversation(nick, txt);
+            Chat.updateChatConversation(nick, txt);
         }
         return true;
     },

util.js

+/**
+ * Utility functions.
+ */
+var Util = (function (my) {
+
+    /**
+     * Returns the text width for the given element.
+     *
+     * @param el the element
+     */
+    my.getTextWidth = function(el) {
+        return (el.clientWidth + 1);
+    };
+
+    /**
+     * Returns the text height for the given element.
+     *
+     * @param el the element
+     */
+    my.getTextHeight = function(el) {
+        return (el.clientHeight + 1);
+    };
+
+    /**
+     * Casts the given number to integer.
+     *
+     * @param number the number to cast
+     */
+    my.toInteger = function(number) {
+        return Math.round(Number(number));
+    };
+
+    /**
+     * Plays the sound given by id.
+     *
+     * @param id the identifier of the audio element.
+     */
+    my.playSoundNotification = function(id) {
+        document.getElementById(id).play();
+    };
+
+    return my;
+}(Util || {}));