annotate core.js @ 1316:279930a008ca

All interfaces support comment boxes. Comment box identification matches presented tag (for instance, AB will be Comment on fragment A, rather than 1). Tighter buffer loading protocol, audioObjects register with the buffer rather than checking for buffer existence (which can be buggy depending on the buffer state). Buffers now have a state to ensure exact location in loading chain (downloading, decoding, LUFS, ready).

/**
 * core.js
 * 
 * Main script to run, calls all other core functions and manages loading/store to backend.
 * Also contains all global variables.
 */

/* create the web audio API context and store in audioContext*/
var audioContext; // Hold the browser web audio API
var projectXML; // Hold the parsed setup XML
var schemaXSD; // Hold the parsed schema XSD
var specification;
var interfaceContext;
var storage;
var popup; // Hold the interfacePopup object
var testState;
var currentTrackOrder = []; // Hold the current XML tracks in their (randomised) order
var audioEngineContext; // The custome AudioEngine object
var projectReturn; // Hold the URL for the return


// Add a prototype to the bufferSourceNode to reference to the audioObject holding it
AudioBufferSourceNode.prototype.owner = undefined;
// Add a prototype to the bufferNode to hold the desired LINEAR gain
AudioBuffer.prototype.playbackGain = undefined;
// Add a prototype to the bufferNode to hold the computed LUFS loudness
AudioBuffer.prototype.lufs = undefined;

// Firefox does not have an XMLDocument.prototype.getElementsByName
// and there is no searchAll style command, this custom function will
// search all children recusrively for the name. Used for XSD where all
// element nodes must have a name and therefore can pull the schema node
XMLDocument.prototype.getAllElementsByName = function(name)
{
    name = String(name);
    var selected = this.documentElement.getAllElementsByName(name);
    return selected;
}

Element.prototype.getAllElementsByName = function(name)
{
    name = String(name);
    var selected = [];
    var node = this.firstElementChild;
    while(node != null)
    {
        if (node.getAttribute('name') == name)
        {
            selected.push(node);
        }
        if (node.childElementCount > 0)
        {
            selected = selected.concat(node.getAllElementsByName(name));
        }
        node = node.nextElementSibling;
    }
    return selected;
}

XMLDocument.prototype.getAllElementsByTagName = function(name)
{
    name = String(name);
    var selected = this.documentElement.getAllElementsByTagName(name);
    return selected;
}

Element.prototype.getAllElementsByTagName = function(name)
{
    name = String(name);
    var selected = [];
    var node = this.firstElementChild;
    while(node != null)
    {
        if (node.nodeName == name)
        {
            selected.push(node);
        }
        if (node.childElementCount > 0)
        {
            selected = selected.concat(node.getAllElementsByTagName(name));
        }
        node = node.nextElementSibling;
    }
    return selected;
}

// Firefox does not have an XMLDocument.prototype.getElementsByName
if (typeof XMLDocument.prototype.getElementsByName != "function") {
    XMLDocument.prototype.getElementsByName = function(name)
    {
        name = String(name);
        var node = this.documentElement.firstElementChild;
        var selected = [];
        while(node != null)
        {
            if (node.getAttribute('name') == name)
            {
                selected.push(node);
            }
            node = node.nextElementSibling;
        }
        return selected;
    }
}

window.onload = function() {
	// Function called once the browser has loaded all files.
	// This should perform any initial commands such as structure / loading documents
	
	// Create a web audio API context
	// Fixed for cross-browser support
	var AudioContext = window.AudioContext || window.webkitAudioContext;
	audioContext = new AudioContext;
	
	// Create test state
	testState = new stateMachine();
	
	// Create the popup interface object
	popup = new interfacePopup();
	
	// Create the specification object
	specification = new Specification();
	
	// Create the interface object
	interfaceContext = new Interface(specification);
	
	// Create the storage object
	storage = new Storage();
	// Define window callbacks for interface
	window.onresize = function(event){interfaceContext.resizeWindow(event);};
};

function loadProjectSpec(url) {
	// Load the project document from the given URL, decode the XML and instruct audioEngine to get audio data
	// If url is null, request client to upload project XML document
	var xmlhttp = new XMLHttpRequest();
	xmlhttp.open("GET",'test-schema.xsd',true);
	xmlhttp.onload = function()
	{
		schemaXSD = xmlhttp.response;
		var parse = new DOMParser();
		specification.schema = parse.parseFromString(xmlhttp.response,'text/xml');
		var r = new XMLHttpRequest();
		r.open('GET',url,true);
		r.onload = function() {
			loadProjectSpecCallback(r.response);
		};
		r.send();
	};
	xmlhttp.send();
};

function loadProjectSpecCallback(response) {
	// Function called after asynchronous download of XML project specification
	//var decode = $.parseXML(response);
	//projectXML = $(decode);
	
	// First perform XML schema validation
	var Module = {
		xml: response,
		schema: schemaXSD,
		arguments:["--noout", "--schema", 'test-schema.xsd','document.xml']
	};
	
	var xmllint = validateXML(Module);
	console.log(xmllint);
	if(xmllint != 'document.xml validates\n')
	{
		document.getElementsByTagName('body')[0].innerHTML = null;
		var msg = document.createElement("h3");
		msg.textContent = "FATAL ERROR";
		var span = document.createElement("h4");
		span.textContent = "The XML validator returned the following errors when decoding your XML file";
		document.getElementsByTagName('body')[0].appendChild(msg);
		document.getElementsByTagName('body')[0].appendChild(span);
		xmllint = xmllint.split('\n');
		for (var i in xmllint)
		{
			document.getElementsByTagName('body')[0].appendChild(document.createElement('br'));
			var span = document.createElement("span");
			span.textContent = xmllint[i];
			document.getElementsByTagName('body')[0].appendChild(span);
		}
		return;
	}
	
	var parse = new DOMParser();
	projectXML = parse.parseFromString(response,'text/xml');
	var errorNode = projectXML.getElementsByTagName('parsererror');
	if (errorNode.length >= 1)
	{
		var msg = document.createElement("h3");
		msg.textContent = "FATAL ERROR";
		var span = document.createElement("span");
		span.textContent = "The XML parser returned the following errors when decoding your XML file";
		document.getElementsByTagName('body')[0].innerHTML = null;
		document.getElementsByTagName('body')[0].appendChild(msg);
		document.getElementsByTagName('body')[0].appendChild(span);
		document.getElementsByTagName('body')[0].appendChild(errorNode[0]);
		return;
	}
	
	// Build the specification
	specification.decode(projectXML);
	storage.initialise();
	/// CHECK FOR SAMPLE RATE COMPATIBILITY
	if (specification.sampleRate != undefined) {
		if (Number(specification.sampleRate) != audioContext.sampleRate) {
			var errStr = 'Sample rates do not match! Requested '+Number(specification.sampleRate)+', got '+audioContext.sampleRate+'. Please set the sample rate to match before completing this test.';
			alert(errStr);
			return;
		}
	}
	
	// Detect the interface to use and load the relevant javascripts.
	var interfaceJS = document.createElement('script');
	interfaceJS.setAttribute("type","text/javascript");
	switch(specification.interface)
	{
		case "APE":
		interfaceJS.setAttribute("src","interfaces/ape.js");
		
		// APE comes with a css file
		var css = document.createElement('link');
		css.rel = 'stylesheet';
		css.type = 'text/css';
		css.href = 'interfaces/ape.css';
		
		document.getElementsByTagName("head")[0].appendChild(css);
		break;
		
		case "MUSHRA":
		interfaceJS.setAttribute("src","interfaces/mushra.js");
		
		// MUSHRA comes with a css file
		var css = document.createElement('link');
		css.rel = 'stylesheet';
		css.type = 'text/css';
		css.href = 'interfaces/mushra.css';
		
		document.getElementsByTagName("head")[0].appendChild(css);
		break;
		
		case "AB":
		interfaceJS.setAttribute("src","interfaces/AB.js");
		
		// AB comes with a css file
		var css = document.createElement('link');
		css.rel = 'stylesheet';
		css.type = 'text/css';
		css.href = 'interfaces/AB.css';
		
		document.getElementsByTagName("head")[0].appendChild(css);
		break;
		case "Bipolar":
		case "ACR":
		case "DCR":
		case "CCR":
		case "ABC":
		// Above enumerate to horizontal sliders
		interfaceJS.setAttribute("src","interfaces/horizontal-sliders.js");
		
		// horizontal-sliders comes with a css file
		var css = document.createElement('link');
		css.rel = 'stylesheet';
		css.type = 'text/css';
		css.href = 'interfaces/horizontal-sliders.css';
		
		document.getElementsByTagName("head")[0].appendChild(css);
		break;
		case "discrete":
		case "likert":
		// Above enumerate to horizontal discrete radios
		interfaceJS.setAttribute("src","interfaces/discrete.js");
		
		// horizontal-sliders comes with a css file
		var css = document.createElement('link');
		css.rel = 'stylesheet';
		css.type = 'text/css';
		css.href = 'interfaces/discrete.css';
		
		document.getElementsByTagName("head")[0].appendChild(css);
		break;
	}
	document.getElementsByTagName("head")[0].appendChild(interfaceJS);
	
	// Create the audio engine object
	audioEngineContext = new AudioEngine(specification);
	
	$(specification.pages).each(function(index,elem){
		$(elem.audioElements).each(function(i,audioElem){
			var URL = elem.hostURL + audioElem.url;
			var buffer = null;
			for (var i=0; i<audioEngineContext.buffers.length; i++)
			{
				if (URL == audioEngineContext.buffers[i].url)
				{
					buffer = audioEngineContext.buffers[i];
					break;
				}
			}
			if (buffer == null)
			{
				buffer = new audioEngineContext.bufferObj();
				buffer.getMedia(URL);
				audioEngineContext.buffers.push(buffer);
			}
		});
	});
}

function createProjectSave(destURL) {
	// Save the data from interface into XML and send to destURL
	// If destURL is null then download XML in client
	// Now time to render file locally
	var xmlDoc = interfaceXMLSave();
	var parent = document.createElement("div");
	parent.appendChild(xmlDoc);
	var file = [parent.innerHTML];
	if (destURL == "null" || destURL == undefined) {
		var bb = new Blob(file,{type : 'application/xml'});
		var dnlk = window.URL.createObjectURL(bb);
		var a = document.createElement("a");
		a.hidden = '';
		a.href = dnlk;
		a.download = "save.xml";
		a.textContent = "Save File";
		
		popup.showPopup();
		popup.popupContent.innerHTML = "</span>Please save the file below to give to your test supervisor</span><br>";
		popup.popupContent.appendChild(a);
	} else {
		var xmlhttp = new XMLHttpRequest;
		xmlhttp.open("POST",destURL,true);
		xmlhttp.setRequestHeader('Content-Type', 'text/xml');
		xmlhttp.onerror = function(){
			console.log('Error saving file to server! Presenting download locally');
			createProjectSave(null);
		};
		xmlhttp.onreadystatechange  = function() {
			console.log(xmlhttp.status);
			if (xmlhttp.status != 200 && xmlhttp.readyState == 4) {
				createProjectSave(null);
			} else {
				if (xmlhttp.responseXML == null)
				{
					createProjectSave('null');
				}
				var response = xmlhttp.responseXML.childNodes[0];
				if (response.getAttribute('state') == "OK")
				{
					var file = response.getElementsByTagName('file')[0];
					console.log('Save OK: Filename '+file.textContent+','+file.getAttribute('bytes')+'B');
					popup.showPopup();
					popup.popupContent.innerHTML = null;
					popup.popupContent.textContent = "Thank you!";
				} else {
					var message = response.getElementsByTagName('message')[0];
					errorSessionDump(message.textContent);
				}
			}
		};
		xmlhttp.send(file);
		popup.showPopup();
		popup.popupContent.innerHTML = null;
		popup.popupContent.textContent = "Submitting. Please Wait";
	}
}

function errorSessionDump(msg){
	// Create the partial interface XML save
	// Include error node with message on why the dump occured
	popup.showPopup();
	popup.popupContent.innerHTML = null;
	var err = document.createElement('error');
	var parent = document.createElement("div");
	if (typeof msg === "object")
	{
		err.appendChild(msg);
		popup.popupContent.appendChild(msg);
		
	} else {
		err.textContent = msg;
		popup.popupContent.innerHTML = "ERROR : "+msg;
	}
	var xmlDoc = interfaceXMLSave();
	xmlDoc.appendChild(err);
	parent.appendChild(xmlDoc);
	var file = [parent.innerHTML];
	var bb = new Blob(file,{type : 'application/xml'});
	var dnlk = window.URL.createObjectURL(bb);
	var a = document.createElement("a");
	a.hidden = '';
	a.href = dnlk;
	a.download = "save.xml";
	a.textContent = "Save File";
	
	
	
	popup.popupContent.appendChild(a);
}

// Only other global function which must be defined in the interface class. Determines how to create the XML document.
function interfaceXMLSave(){
	// Create the XML string to be exported with results
	return storage.finish();
}

function linearToDecibel(gain)
{
	return 20.0*Math.log10(gain);
}

function decibelToLinear(gain)
{
	return Math.pow(10,gain/20.0);
}

function interfacePopup() {
	// Creates an object to manage the popup
	this.popup = null;
	this.popupContent = null;
	this.popupTitle = null;
	this.popupResponse = null;
	this.buttonProceed = null;
	this.buttonPrevious = null;
	this.popupOptions = null;
	this.currentIndex = null;
	this.node = null;
	this.store = null;
	$(window).keypress(function(e){
			if (e.keyCode == 13 && popup.popup.style.visibility == 'visible')
			{
				console.log(e);
				popup.buttonProceed.onclick();
				e.preventDefault();
			}
		});
	
	this.createPopup = function(){
		// Create popup window interface
		var insertPoint = document.getElementById("topLevelBody");
		var blank = document.createElement('div');
		blank.className = 'testHalt';
		
		this.popup = document.createElement('div');
		this.popup.id = 'popupHolder';
		this.popup.className = 'popupHolder';
		this.popup.style.position = 'absolute';
		this.popup.style.left = (window.innerWidth/2)-250 + 'px';
		this.popup.style.top = (window.innerHeight/2)-125 + 'px';
		
		this.popupContent = document.createElement('div');
		this.popupContent.id = 'popupContent';
		this.popupContent.style.marginTop = '20px';
		this.popupContent.style.marginBottom = '5px';
		this.popup.appendChild(this.popupContent);
		
		var titleHolder = document.createElement('div');
		titleHolder.id = 'popupTitleHolder';
		titleHolder.align = 'center';
		titleHolder.style.width = 'inherit';
		titleHolder.style.minHeight = '25px';
		titleHolder.style.maxHeight = '250px';
		titleHolder.style.overflow = 'auto';
		titleHolder.style.marginBottom = '5px';
		
		this.popupTitle = document.createElement('span');
		this.popupTitle.id = 'popupTitle';
		titleHolder.appendChild(this.popupTitle);
		this.popupContent.appendChild(titleHolder);
		
		this.popupResponse = document.createElement('div');
		this.popupResponse.id = 'popupResponse';
		this.popupResponse.align = 'center';
		this.popupResponse.style.width = 'inherit';
		this.popupResponse.style.minHeight = '50px';
		this.popupResponse.style.maxHeight = '320px';
		this.popupResponse.style.overflow = 'auto';
		this.popupContent.appendChild(this.popupResponse);
		
		this.buttonProceed = document.createElement('button');
		this.buttonProceed.className = 'popupButton';
		this.buttonProceed.position = 'relative';
		this.buttonProceed.style.left = '390px';
		this.buttonProceed.innerHTML = 'Next';
		this.buttonProceed.onclick = function(){popup.proceedClicked();};
		
		this.buttonPrevious = document.createElement('button');
		this.buttonPrevious.className = 'popupButton';
		this.buttonPrevious.position = 'relative';
		this.buttonPrevious.style.left = '10px';
		this.buttonPrevious.innerHTML = 'Back';
		this.buttonPrevious.onclick = function(){popup.previousClick();};
		
		this.popupContent.appendChild(this.buttonPrevious);
		this.popupContent.appendChild(this.buttonProceed);
		
		this.popup.style.zIndex = -1;
		this.popup.style.visibility = 'hidden';
		blank.style.zIndex = -2;
		blank.style.visibility = 'hidden';
		insertPoint.appendChild(this.popup);
		insertPoint.appendChild(blank);
	};
	
	this.showPopup = function(){
		if (this.popup == null) {
			this.createPopup();
		}
		this.popup.style.zIndex = 3;
		this.popup.style.visibility = 'visible';
		var blank = document.getElementsByClassName('testHalt')[0];
		blank.style.zIndex = 2;
		blank.style.visibility = 'visible';
	};
	
	this.hidePopup = function(){
		this.popup.style.zIndex = -1;
		this.popup.style.visibility = 'hidden';
		var blank = document.getElementsByClassName('testHalt')[0];
		blank.style.zIndex = -2;
		blank.style.visibility = 'hidden';
		this.buttonPrevious.style.visibility = 'inherit';
	};
	
	this.postNode = function() {
		// This will take the node from the popupOptions and display it
		var node = this.popupOptions[this.currentIndex];
		this.popupResponse.innerHTML = null;
		this.popupTitle.textContent = node.specification.statement;
		if (node.specification.type == 'question') {
			var textArea = document.createElement('textarea');
			switch (node.specification.boxsize) {
			case 'small':
				textArea.cols = "20";
				textArea.rows = "1";
				break;
			case 'normal':
				textArea.cols = "30";
				textArea.rows = "2";
				break;
			case 'large':
				textArea.cols = "40";
				textArea.rows = "5";
				break;
			case 'huge':
				textArea.cols = "50";
				textArea.rows = "10";
				break;
			}
            if (node.response == undefined) {
                node.response = "";
            } else {
                textArea.value = node.response;
            }
			this.popupResponse.appendChild(textArea);
			textArea.focus();
		} else if (node.specification.type == 'checkbox') {
            if (node.response == undefined) {
                node.response = Array(node.specification.options.length);
            }
            var index = 0;
			for (var option of node.specification.options) {
				var input = document.createElement('input');
				input.id = option.name;
				input.type = 'checkbox';
				var span = document.createElement('span');
				span.textContent = option.text;
				var hold = document.createElement('div');
				hold.setAttribute('name','option');
				hold.style.padding = '4px';
				hold.appendChild(input);
				hold.appendChild(span);
				this.popupResponse.appendChild(hold);
                if (node.response[index] != undefined){
                    if (node.response[index].checked == true) {
                        input.checked = "true";
                    }
                }
                index++;
			}
		} else if (node.specification.type == 'radio') {
            if (node.response == undefined) {
                node.response = {name: "", text: ""};
            }
            var index = 0;
			for (var option of node.specification.options) {
				var input = document.createElement('input');
				input.id = option.name;
				input.type = 'radio';
				input.name = node.specification.id;
				var span = document.createElement('span');
				span.textContent = option.text;
				var hold = document.createElement('div');
				hold.setAttribute('name','option');
				hold.style.padding = '4px';
				hold.appendChild(input);
				hold.appendChild(span);
				this.popupResponse.appendChild(hold);
                if (input.id == node.response.name) {
                    input.checked = "true";
                }
			}
		} else if (node.specification.type == 'number') {
			var input = document.createElement('input');
			input.type = 'textarea';
			if (node.min != null) {input.min = node.specification.min;}
			if (node.max != null) {input.max = node.specification.max;}
			if (node.step != null) {input.step = node.specification.step;}
            if (node.response != undefined) {
                input.value = node.response;
            }
			this.popupResponse.appendChild(input);
		}
		var content_height = Number(this.popup.offsetHeight.toFixed());
		content_height -= Number(this.popupContent.offsetHeight.toFixed());
		content_height -=Number(this.buttonProceed.offsetHeight.toFixed());
		content_height = content_height + "px";
		this.buttonProceed.style.top = content_height;
		this.buttonPrevious.style.top = content_height;
		if(this.currentIndex+1 == this.popupOptions.length) {
			if (this.node.location == "pre") {
				this.buttonProceed.textContent = 'Start';
			} else {
				this.buttonProceed.textContent = 'Submit';
			}
		} else {
			this.buttonProceed.textContent = 'Next';
		}
		if(this.currentIndex > 0)
			this.buttonPrevious.style.visibility = 'visible';
		else
			this.buttonPrevious.style.visibility = 'hidden';
	};
	
	this.initState = function(node,store) {
		//Call this with your preTest and postTest nodes when needed to
		// initialise the popup procedure.
		if (node.options.length > 0) {
			this.popupOptions = [];
			this.node = node;
			this.store = store;
			for (var opt of node.options)
			{
				this.popupOptions.push({
					specification: opt,
					response: null
				});
			}			
			this.currentIndex = 0;
			this.showPopup();
			this.postNode();
		} else {
			advanceState();
		}
	};
	
	this.proceedClicked = function() {
		// Each time the popup button is clicked!
		var node = this.popupOptions[this.currentIndex];
		if (node.specification.type == 'question') {
			// Must extract the question data
			var textArea = $(popup.popupContent).find('textarea')[0];
			if (node.specification.mandatory == true && textArea.value.length == 0) {
				alert('This question is mandatory');
				return;
			} else {
				// Save the text content
				console.log("Question: "+ node.specification.statement);
				console.log("Question Response: "+ textArea.value);
				node.response = textArea.value;
			}
		} else if (node.specification.type == 'checkbox') {
			// Must extract checkbox data
			console.log("Checkbox: "+ node.specification.statement);
			var inputs = this.popupResponse.getElementsByTagName('input');
			node.response = [];
			for (var i=0; i<node.specification.options.length; i++) {
				node.response.push({
					name: node.specification.options[i].name,
					text: node.specification.options[i].text,
					checked: inputs[i].checked
				});
				console.log(node.specification.options[i].name+": "+ inputs[i].checked);
			}
		} else if (node.specification.type == "radio") {
			var optHold = this.popupResponse;
			console.log("Radio: "+ node.specification.statement);
			node.response = null;
			var i=0;
			var inputs = optHold.getElementsByTagName('input');
			while(node.response == null) {
				if (i == inputs.length)
				{
					if (node.specification.mandatory == true)
					{
						alert("This radio is mandatory");
					} else {
						node.response = -1;
					}
					return;
				}
				if (inputs[i].checked == true) {
					node.response = node.specification.options[i];
					console.log("Selected: "+ node.specification.options[i].name);
				}
				i++;
			}
		} else if (node.specification.type == "number") {
			var input = this.popupContent.getElementsByTagName('input')[0];
			if (node.mandatory == true && input.value.length == 0) {
				alert('This question is mandatory. Please enter a number');
				return;
			}
			var enteredNumber = Number(input.value);
			if (isNaN(enteredNumber)) {
				alert('Please enter a valid number');
				return;
			}
			if (enteredNumber < node.min && node.min != null) {
				alert('Number is below the minimum value of '+node.min);
				return;
			}
			if (enteredNumber > node.max && node.max != null) {
				alert('Number is above the maximum value of '+node.max);
				return;
			}
			node.response = input.value;
		}
		this.currentIndex++;
		if (this.currentIndex < this.popupOptions.length) {
			this.postNode();
		} else {
			// Reached the end of the popupOptions
			this.hidePopup();
			for (var node of this.popupOptions)
			{
				this.store.postResult(node);
			}
			advanceState();
		}
	};
	
	this.previousClick = function() {
		// Triggered when the 'Back' button is clicked in the survey
		if (this.currentIndex > 0) {
			this.currentIndex--;
			this.postNode();
		}
	};
	
	this.resize = function(event)
	{
		// Called on window resize;
		if (this.popup != null) {
			this.popup.style.left = (window.innerWidth/2)-250 + 'px';
			this.popup.style.top = (window.innerHeight/2)-125 + 'px';
			var blank = document.getElementsByClassName('testHalt')[0];
			blank.style.width = window.innerWidth;
			blank.style.height = window.innerHeight;
		}
	};
}

function advanceState()
{
	// Just for complete clarity
	testState.advanceState();
}

function stateMachine()
{
	// Object prototype for tracking and managing the test state
	this.stateMap = [];
	this.preTestSurvey = null;
	this.postTestSurvey = null;
	this.stateIndex = null;
	this.currentStateMap = null;
	this.currentStatePosition = null;
    this.currentStore = null;
	this.initialise = function(){
		
		// Get the data from Specification
		var pageHolder = [];
		for (var page of specification.pages)
		{
			pageHolder.push(page);
		}
		if (specification.randomiseOrder)
		{
			pageHolder = randomiseOrder(pageHolder);
		}
		for (var i=0; i<pageHolder.length; i++)
		{
			pageHolder[i].presentedId = i;
		}
		for (var i=0; i<specification.pages.length; i++)
		{
			if (specification.testPages < i && specification.testPages != 0) {break;}
			this.stateMap.push(pageHolder[i]);
			
		}
		if (specification.preTest != null) {this.preTestSurvey = specification.preTest;}
		if (specification.postTest != null) {this.postTestSurvey = specification.postTest;}
		
		if (this.stateMap.length > 0) {
			if(this.stateIndex != null) {
				console.log('NOTE - State already initialise');
			}
			this.stateIndex = -1;
		} else {
			console.log('FATAL - StateMap not correctly constructed. EMPTY_STATE_MAP');
		}
	};
	this.advanceState = function(){
		if (this.stateIndex == null) {
			this.initialise();
		}
		if (this.stateIndex == -1) {
			this.stateIndex++;
			console.log('Starting test...');
			if (this.preTestSurvey != null)
			{
				popup.initState(this.preTestSurvey,storage.globalPreTest);
			} else {
				this.advanceState();
			}
		} else if (this.stateIndex == this.stateMap.length)
		{
			// All test pages complete, post test
			console.log('Ending test ...');
			this.stateIndex++;
			if (this.postTestSurvey == null) {
				this.advanceState();
			} else {
				popup.initState(this.postTestSurvey,storage.globalPostTest);
			}
		} else if (this.stateIndex > this.stateMap.length)
		{
			createProjectSave(specification.projectReturn);
		}
		else
		{
			if (this.currentStateMap == null)
			{
				this.currentStateMap = this.stateMap[this.stateIndex];
				if (this.currentStateMap.randomiseOrder)
				{
					this.currentStateMap.audioElements = randomiseOrder(this.currentStateMap.audioElements);
				}
                this.currentStore = storage.createTestPageStore(this.currentStateMap);
				if (this.currentStateMap.preTest != null)
				{
					this.currentStatePosition = 'pre';
					popup.initState(this.currentStateMap.preTest,storage.testPages[this.stateIndex].preTest);
				} else {
					this.currentStatePosition = 'test';
				}
				interfaceContext.newPage(this.currentStateMap,storage.testPages[this.stateIndex]);
				return;
			}
			switch(this.currentStatePosition)
			{
			case 'pre':
				this.currentStatePosition = 'test';
				break;
			case 'test':
				this.currentStatePosition = 'post';
				// Save the data
				this.testPageCompleted();
				if (this.currentStateMap.postTest == null)
				{
					this.advanceState();
					return;
				} else {
					popup.initState(this.currentStateMap.postTest,storage.testPages[this.stateIndex].postTest);
				}
				break;
			case 'post':
				this.stateIndex++;
				this.currentStateMap = null;
				this.advanceState();
				break;
			};
		}
	};
	
	this.testPageCompleted = function() {
		// Function called each time a test page has been completed
		var storePoint = storage.testPages[this.stateIndex];
		// First get the test metric
		
		var metric = storePoint.XMLDOM.getElementsByTagName('metric')[0];
		if (audioEngineContext.metric.enableTestTimer)
		{
			var testTime = storePoint.parent.document.createElement('metricresult');
			testTime.id = 'testTime';
			testTime.textContent = audioEngineContext.timer.testDuration;
			metric.appendChild(testTime);
		}
		
		var audioObjects = audioEngineContext.audioObjects;
		for (var ao of audioEngineContext.audioObjects) 
		{
			ao.exportXMLDOM();
		}
		for (var element of interfaceContext.commentQuestions)
		{
			element.exportXMLDOM(storePoint);
		}
		pageXMLSave(storePoint.XMLDOM, this.currentStateMap);
	};
}

function AudioEngine(specification) {
	
	// Create two output paths, the main outputGain and fooGain.
	// Output gain is default to 1 and any items for playback route here
	// Foo gain is used for analysis to ensure paths get processed, but are not heard
	// because web audio will optimise and any route which does not go to the destination gets ignored.
	this.outputGain = audioContext.createGain();
	this.fooGain = audioContext.createGain();
	this.fooGain.gain = 0;
	
	// Use this to detect playback state: 0 - stopped, 1 - playing
	this.status = 0;
	
	// Connect both gains to output
	this.outputGain.connect(audioContext.destination);
	this.fooGain.connect(audioContext.destination);
	
	// Create the timer Object
	this.timer = new timer();
	// Create session metrics
	this.metric = new sessionMetrics(this,specification);
	
	this.loopPlayback = false;
	
	this.pageStore = null;
	
	// Create store for new audioObjects
	this.audioObjects = [];
	
	this.buffers = [];
	this.bufferObj = function()
	{
		this.url = null;
		this.buffer = null;
		this.xmlRequest = new XMLHttpRequest();
		this.xmlRequest.parent = this;
		this.users = [];
        this.progress = 0;
        this.status = 0;
		this.ready = function()
		{
            if (this.status >= 2)
            {
                this.status = 3;
            }
			for (var i=0; i<this.users.length; i++)
			{
				this.users[i].state = 1;
				if (this.users[i].interfaceDOM != null)
				{
					this.users[i].bufferLoaded(this);
				}
			}
		};
		this.getMedia = function(url) {
			this.url = url;
			this.xmlRequest.open('GET',this.url,true);
			this.xmlRequest.responseType = 'arraybuffer';
			
			var bufferObj = this;
			
			// Create callback to decode the data asynchronously
			this.xmlRequest.onloadend = function() {
                // Use inbuilt WAVE decoder first
                var waveObj = new WAVE();
                if (waveObj.open(bufferObj.xmlRequest.response) == 0)
                {
                    bufferObj.buffer = audioContext.createBuffer(waveObj.num_channels,waveObj.num_samples,waveObj.sample_rate);
                    for (var c=0; c<waveObj.num_channels; c++)
                    {
                        var buffer_ptr = bufferObj.buffer.getChannelData(c);
                        for (var n=0; n<waveObj.num_samples; n++)
                        {
                            buffer_ptr[n] = waveObj.decoded_data[c][n];
                        }
                    }
                    
                    delete waveObj;
                } else {
                    audioContext.decodeAudioData(bufferObj.xmlRequest.response, function(decodedData) {
                        bufferObj.buffer = decodedData;
                    }, function(e){
                        // Should only be called if there was an error, but sometimes gets called continuously
                        // Check here if the error is genuine
                        if (bufferObj.xmlRequest.response == undefined) {
                            // Genuine error
                            console.log('FATAL - Error loading buffer on '+audioObj.id);
                            if (request.status == 404)
                            {
                                console.log('FATAL - Fragment '+audioObj.id+' 404 error');
                                console.log('URL: '+audioObj.url);
                                errorSessionDump('Fragment '+audioObj.id+' 404 error');
                            }
                            this.status = -1;
                        }
                    });
                }
                if (bufferObj.buffer != undefined)
                {
                    bufferObj.status = 2;
                    calculateLoudness(bufferObj,"I");
                }
			};
			this.progress = 0;
			this.progressCallback = function(event){
				if (event.lengthComputable)
				{
					this.parent.progress = event.loaded / event.total;
					for (var i=0; i<this.parent.users.length; i++)
					{
						if(this.parent.users[i].interfaceDOM != null)
						{
							if (typeof this.parent.users[i].interfaceDOM.updateLoading === "function")
							{
								this.parent.users[i].interfaceDOM.updateLoading(this.parent.progress*100);
							}
						}
					}
				}
			};
			this.xmlRequest.addEventListener("progress", this.progressCallback);
            this.status = 1;
			this.xmlRequest.send();
		};
        
        this.registerAudioObject = function(audioObject)
        {
            // Called by an audioObject to register to the buffer for use
            // First check if already in the register pool
            for (var objects of this.users)
            {
                if (audioObject.id == objects.id){return 0;}
            }
            this.users.push(audioObject);
            if (this.status == 3)
            {
                // The buffer is already ready, trigger bufferLoaded
                audioObject.bufferLoaded(this);
            }
        }
	};
	
	this.play = function(id) {
		// Start the timer and set the audioEngine state to playing (1)
		if (this.status == 0 && this.loopPlayback) {
			// Check if all audioObjects are ready
			if(this.checkAllReady())
			{
				this.status = 1;
				this.setSynchronousLoop();
			}
		}
		else
		{
			this.status = 1;
		}
		if (this.status== 1) {
			this.timer.startTest();
			if (id == undefined) {
				id = -1;
				console.log('FATAL - Passed id was undefined - AudioEngineContext.play(id)');
				return;
			} else {
				interfaceContext.playhead.setTimePerPixel(this.audioObjects[id]);
			}
			if (this.loopPlayback) {
                var setTime = audioContext.currentTime+2;
				for (var i=0; i<this.audioObjects.length; i++)
				{
					this.audioObjects[i].play(setTime-2);
					if (id == i) {
						this.audioObjects[i].loopStart(setTime);
					} else {
						this.audioObjects[i].loopStop(setTime);
					}
				}
			} else {
                var setTime = audioContext.currentTime+0.1;
				for (var i=0; i<this.audioObjects.length; i++)
				{
					if (i != id) {
						this.audioObjects[i].stop(setTime);
					} else if (i == id) {
						this.audioObjects[id].play(setTime);
					}
				}
			}
			interfaceContext.playhead.start();
		}
	};
	
	this.stop = function() {
		// Send stop and reset command to all playback buffers and set audioEngine state to stopped (1)
		if (this.status == 1) {
            var setTime = audioContext.currentTime+0.1;
			for (var i=0; i<this.audioObjects.length; i++)
			{
				this.audioObjects[i].stop(setTime);
			}
			interfaceContext.playhead.stop();
			this.status = 0;
		}
	};
	
	this.newTrack = function(element) {
		// Pull data from given URL into new audio buffer
		// URLs must either be from the same source OR be setup to 'Access-Control-Allow-Origin'
		
		// Create the audioObject with ID of the new track length;
		audioObjectId = this.audioObjects.length;
		this.audioObjects[audioObjectId] = new audioObject(audioObjectId);

		// Check if audioObject buffer is currently stored by full URL
		var URL = testState.currentStateMap.hostURL + element.url;
		var buffer = null;
		for (var i=0; i<this.buffers.length; i++)
		{
			if (URL == this.buffers[i].url)
			{
				buffer = this.buffers[i];
				break;
			}
		}
		if (buffer == null)
		{
			console.log("[WARN]: Buffer was not loaded in pre-test! "+URL);
			buffer = new this.bufferObj();
            this.buffers.push(buffer);
			buffer.getMedia(URL);
		}
		this.audioObjects[audioObjectId].specification = element;
		this.audioObjects[audioObjectId].url = URL;
		// Obtain store node
		var aeNodes = this.pageStore.XMLDOM.getElementsByTagName('audioelement');
		for (var i=0; i<aeNodes.length; i++)
		{
			if(aeNodes[i].id == element.id)
			{
				this.audioObjects[audioObjectId].storeDOM = aeNodes[i];
				break;
			}
		}
        buffer.registerAudioObject(this.audioObjects[audioObjectId]);
		return this.audioObjects[audioObjectId];
	};
	
	this.newTestPage = function(store) {
		this.pageStore = store;
		this.state = 0;
		this.audioObjectsReady = false;
		this.metric.reset();
		for (var i=0; i < this.buffers.length; i++)
		{
			this.buffers[i].users = [];
		}
		this.audioObjects = [];
	};
	
	this.checkAllPlayed = function() {
		arr = [];
		for (var id=0; id<this.audioObjects.length; id++) {
			if (this.audioObjects[id].metric.wasListenedTo == false) {
				arr.push(this.audioObjects[id].id);
			}
		}
		return arr;
	};
	
	this.checkAllReady = function() {
		var ready = true;
		for (var i=0; i<this.audioObjects.length; i++) {
			if (this.audioObjects[i].state == 0) {
				// Track not ready
				console.log('WAIT -- audioObject '+i+' not ready yet!');
				ready = false;
			};
		}
		return ready;
	};
	
	this.setSynchronousLoop = function() {
		// Pads the signals so they are all exactly the same length
		var length = 0;
		var maxId;
		for (var i=0; i<this.audioObjects.length; i++)
		{
			if (length < this.audioObjects[i].buffer.buffer.length)
			{
				length = this.audioObjects[i].buffer.buffer.length;
				maxId = i;
			}
		}
		// Extract the audio and zero-pad
		for (var i=0; i<this.audioObjects.length; i++)
		{
			var orig = this.audioObjects[i].buffer.buffer;
			var hold = audioContext.createBuffer(orig.numberOfChannels,length,orig.sampleRate);
			for (var c=0; c<orig.numberOfChannels; c++)
			{
				var inData = hold.getChannelData(c);
				var outData = orig.getChannelData(c);
				for (var n=0; n<orig.length; n++)
				{inData[n] = outData[n];}
			}
			hold.playbackGain = orig.playbackGain;
			hold.lufs = orig.lufs;
			this.audioObjects[i].buffer.buffer = hold;
		}
	};
	
}

function audioObject(id) {
	// The main buffer object with common control nodes to the AudioEngine
	
	this.specification;
	this.id = id;
	this.state = 0; // 0 - no data, 1 - ready
	this.url = null; // Hold the URL given for the output back to the results.
	this.metric = new metricTracker(this);
	this.storeDOM = null;
	
	// Bindings for GUI
	this.interfaceDOM = null;
	this.commentDOM = null;
	
	// Create a buffer and external gain control to allow internal patching of effects and volume leveling.
	this.bufferNode = undefined;
	this.outputGain = audioContext.createGain();
	
	this.onplayGain = 1.0;
	
	// Connect buffer to the audio graph
	this.outputGain.connect(audioEngineContext.outputGain);
	
	// the audiobuffer is not designed for multi-start playback
	// When stopeed, the buffer node is deleted and recreated with the stored buffer.
	this.buffer;
	
	this.bufferLoaded = function(callee)
	{
		// Called by the associated buffer when it has finished loading, will then 'bind' the buffer to the
		// audioObject and trigger the interfaceDOM.enable() function for user feedback
		if (audioEngineContext.loopPlayback){
			// First copy the buffer into this.buffer
			this.buffer = new audioEngineContext.bufferObj();
			this.buffer.url = callee.url;
			this.buffer.buffer = audioContext.createBuffer(callee.buffer.numberOfChannels, callee.buffer.length, callee.buffer.sampleRate);
			for (var c=0; c<callee.buffer.numberOfChannels; c++)
			{
				var src = callee.buffer.getChannelData(c);
				var dst = this.buffer.buffer.getChannelData(c);
				for (var n=0; n<src.length; n++)
				{
					dst[n] = src[n];
				}
			}
		} else {
			this.buffer = callee;
		}
		this.state = 1;
		this.buffer.buffer.playbackGain = callee.buffer.playbackGain;
		this.buffer.buffer.lufs = callee.buffer.lufs;
		var targetLUFS = this.specification.parent.loudness || specification.loudness;
		if (typeof targetLUFS === "number")
		{
			this.buffer.buffer.playbackGain = decibelToLinear(targetLUFS - this.buffer.buffer.lufs);
		} else {
			this.buffer.buffer.playbackGain = 1.0;
		}
		if (this.interfaceDOM != null) {
			this.interfaceDOM.enable();
		}
		this.onplayGain = decibelToLinear(this.specification.gain)*this.buffer.buffer.playbackGain;
		this.storeDOM.setAttribute('playGain',linearToDecibel(this.onplayGain));
	};
	
	this.bindInterface = function(interfaceObject)
	{
		this.interfaceDOM = interfaceObject;
		this.metric.initialise(interfaceObject.getValue());
		if (this.state == 1)
		{
			this.interfaceDOM.enable();
		}
		this.storeDOM.setAttribute('presentedId',interfaceObject.getPresentedId());
	};
    
	this.loopStart = function(setTime) {
		this.outputGain.gain.linearRampToValueAtTime(this.onplayGain,setTime);
		this.metric.startListening(audioEngineContext.timer.getTestTime());
        this.interfaceDOM.startPlayback();
	};
	
	this.loopStop = function(setTime) {
		if (this.outputGain.gain.value != 0.0) {
			this.outputGain.gain.linearRampToValueAtTime(0.0,setTime);
			this.metric.stopListening(audioEngineContext.timer.getTestTime());
		}
        this.interfaceDOM.stopPlayback();
	};
	
	this.play = function(startTime) {
		if (this.bufferNode == undefined && this.buffer.buffer != undefined) {
			this.bufferNode = audioContext.createBufferSource();
			this.bufferNode.owner = this;
			this.bufferNode.connect(this.outputGain);
			this.bufferNode.buffer = this.buffer.buffer;
			this.bufferNode.loop = audioEngineContext.loopPlayback;
			this.bufferNode.onended = function(event) {
				// Safari does not like using 'this' to reference the calling object!
				//event.currentTarget.owner.metric.stopListening(audioEngineContext.timer.getTestTime(),event.currentTarget.owner.getCurrentPosition());
				event.currentTarget.owner.stop(audioContext.currentTime+1);
			};
			if (this.bufferNode.loop == false) {
				this.metric.startListening(audioEngineContext.timer.getTestTime());
                this.outputGain.gain.setValueAtTime(this.onplayGain,startTime);
                this.interfaceDOM.startPlayback();
			} else {
                 this.outputGain.gain.setValueAtTime(0.0,startTime);
            }
			this.bufferNode.start(startTime);
		}
	};
	
	this.stop = function(stopTime) {
        this.outputGain.gain.cancelScheduledValues(audioContext.currentTime);
		if (this.bufferNode != undefined)
		{
			this.metric.stopListening(audioEngineContext.timer.getTestTime(),this.getCurrentPosition());
			this.bufferNode.stop(stopTime);
			this.bufferNode = undefined;
		}
        this.outputGain.gain.value = 0.0;
        this.interfaceDOM.stopPlayback();
	};
	
	this.getCurrentPosition = function() {
		var time = audioEngineContext.timer.getTestTime();
		if (this.bufferNode != undefined) {
			if (this.bufferNode.loop == true) {
				if (audioEngineContext.status  == 1) {
					return (time-this.metric.listenStart)%this.buffer.buffer.duration;
				} else {
					return 0;
				}
			} else {
				if (this.metric.listenHold) {
					return time - this.metric.listenStart;
				} else {
					return 0;
				}
			}
		} else {
			return 0;
		}
	};
	
	this.exportXMLDOM = function() {
		var file = storage.document.createElement('file');
		file.setAttribute('sampleRate',this.buffer.buffer.sampleRate);
		file.setAttribute('channels',this.buffer.buffer.numberOfChannels);
		file.setAttribute('sampleCount',this.buffer.buffer.length);
		file.setAttribute('duration',this.buffer.buffer.duration);
		this.storeDOM.appendChild(file);
		if (this.specification.type != 'outside-reference') {
			var interfaceXML = this.interfaceDOM.exportXMLDOM(this);
			if (interfaceXML != null)
			{
				if (interfaceXML.length == undefined) {
					this.storeDOM.appendChild(interfaceXML);
				} else {
					for (var i=0; i<interfaceXML.length; i++)
					{
						this.storeDOM.appendChild(interfaceXML[i]);
					}
				}
			}
			if (this.commentDOM != null) {
				this.storeDOM.appendChild(this.commentDOM.exportXMLDOM(this));
			}
		}
		var nodes = this.metric.exportXMLDOM();
		var mroot = this.storeDOM.getElementsByTagName('metric')[0];
		for (var i=0; i<nodes.length; i++)
		{
			mroot.appendChild(nodes[i]);
		}
	};
}

function timer()
{
	/* Timer object used in audioEngine to keep track of session timings
	 * Uses the timer of the web audio API, so sample resolution
	 */
	this.testStarted = false;
	this.testStartTime = 0;
	this.testDuration = 0;
	this.minimumTestTime = 0; // No minimum test time
	this.startTest = function()
	{
		if (this.testStarted == false)
		{
			this.testStartTime = audioContext.currentTime;
			this.testStarted = true;
			this.updateTestTime();
			audioEngineContext.metric.initialiseTest();
		}
	};
	this.stopTest = function()
	{
		if (this.testStarted)
		{
			this.testDuration = this.getTestTime();
			this.testStarted = false;
		} else {
			console.log('ERR: Test tried to end before beginning');
		}
	};
	this.updateTestTime = function()
	{
		if (this.testStarted)
		{
			this.testDuration = audioContext.currentTime - this.testStartTime;
		}
	};
	this.getTestTime = function()
	{
		this.updateTestTime();
		return this.testDuration;
	};
}

function sessionMetrics(engine,specification)
{
	/* Used by audioEngine to link to audioObjects to minimise the timer call timers;
	 */
	this.engine = engine;
	this.lastClicked = -1;
	this.data = -1;
	this.reset = function() {
		this.lastClicked = -1;
		this.data = -1;
	};
	
	this.enableElementInitialPosition = false;
	this.enableElementListenTracker = false;
	this.enableElementTimer = false;
	this.enableElementTracker = false;
	this.enableFlagListenedTo = false;
	this.enableFlagMoved = false;
	this.enableTestTimer = false;
	// Obtain the metrics enabled
	for (var i=0; i<specification.metrics.enabled.length; i++)
	{
		var node = specification.metrics.enabled[i];
		switch(node)
		{
		case 'testTimer':
			this.enableTestTimer = true;
			break;
		case 'elementTimer':
			this.enableElementTimer = true;
			break;
		case 'elementTracker':
			this.enableElementTracker = true;
			break;
		case 'elementListenTracker':
			this.enableElementListenTracker = true;
			break;
		case 'elementInitialPosition':
			this.enableElementInitialPosition = true;
			break;
		case 'elementFlagListenedTo':
			this.enableFlagListenedTo = true;
			break;
		case 'elementFlagMoved':
			this.enableFlagMoved = true;
			break;
		case 'elementFlagComments':
			this.enableFlagComments = true;
			break;
		}
	}
	this.initialiseTest = function(){};
}

function metricTracker(caller)
{
	/* Custom object to track and collect metric data
	 * Used only inside the audioObjects object.
	 */
	
	this.listenedTimer = 0;
	this.listenStart = 0;
	this.listenHold = false;
	this.initialPosition = -1;
	this.movementTracker = [];
	this.listenTracker =[];
	this.wasListenedTo = false;
	this.wasMoved = false;
	this.hasComments = false;
	this.parent = caller;
	
	this.initialise = function(position)
	{
		if (this.initialPosition == -1) {
			this.initialPosition = position;
			this.moved(0,position);
		}
	};
	
	this.moved = function(time,position)
	{
		if (time > 0) {this.wasMoved = true;}
		this.movementTracker[this.movementTracker.length] = [time, position];
	};
	
	this.startListening = function(time)
	{
		if (this.listenHold == false)
		{
			this.wasListenedTo = true;
			this.listenStart = time;
			this.listenHold = true;
			
			var evnt = document.createElement('event');
			var testTime = document.createElement('testTime');
			testTime.setAttribute('start',time);
			var bufferTime = document.createElement('bufferTime');
			bufferTime.setAttribute('start',this.parent.getCurrentPosition());
			evnt.appendChild(testTime);
			evnt.appendChild(bufferTime);
			this.listenTracker.push(evnt);
			
			console.log('slider ' + this.parent.id + ' played (' + time + ')'); // DEBUG/SAFETY: show played slider id
		}
	};
	
	this.stopListening = function(time,bufferStopTime)
	{
		if (this.listenHold == true)
		{
			var diff = time - this.listenStart;
			this.listenedTimer += (diff);
			this.listenStart = 0;
			this.listenHold = false;
			
			var evnt = this.listenTracker[this.listenTracker.length-1];
			var testTime = evnt.getElementsByTagName('testTime')[0];
			var bufferTime = evnt.getElementsByTagName('bufferTime')[0];
			testTime.setAttribute('stop',time);
			if (bufferStopTime == undefined) {
				bufferTime.setAttribute('stop',this.parent.getCurrentPosition());
			} else {
				bufferTime.setAttribute('stop',bufferStopTime);
			}
			console.log('slider ' + this.parent.id + ' played for (' + diff + ')'); // DEBUG/SAFETY: show played slider id
		}
	};
	
	this.exportXMLDOM = function() {
		var storeDOM = [];
		if (audioEngineContext.metric.enableElementTimer) {
			var mElementTimer = storage.document.createElement('metricresult');
			mElementTimer.setAttribute('name','enableElementTimer');
			mElementTimer.textContent = this.listenedTimer;
			storeDOM.push(mElementTimer);
		}
		if (audioEngineContext.metric.enableElementTracker) {
			var elementTrackerFull = storage.document.createElement('metricResult');
			elementTrackerFull.setAttribute('name','elementTrackerFull');
			for (var k=0; k<this.movementTracker.length; k++)
			{
				var timePos = storage.document.createElement('timePos');
				timePos.id = k;
				var time = storage.document.createElement('time');
				time.textContent = this.movementTracker[k][0];
				var position = document.createElement('position');
				position.textContent = this.movementTracker[k][1];
				timePos.appendChild(time);
				timePos.appendChild(position);
				elementTrackerFull.appendChild(timePos);
			}
			storeDOM.push(elementTrackerFull);
		}
		if (audioEngineContext.metric.enableElementListenTracker) {
			var elementListenTracker = storage.document.createElement('metricResult');
			elementListenTracker.setAttribute('name','elementListenTracker');
			for (var k=0; k<this.listenTracker.length; k++) {
				elementListenTracker.appendChild(this.listenTracker[k]);
			}
			storeDOM.push(elementListenTracker);
		}
		if (audioEngineContext.metric.enableElementInitialPosition) {
			var elementInitial = storage.document.createElement('metricResult');
			elementInitial.setAttribute('name','elementInitialPosition');
			elementInitial.textContent = this.initialPosition;
			storeDOM.push(elementInitial);
		}
		if (audioEngineContext.metric.enableFlagListenedTo) {
			var flagListenedTo = storage.document.createElement('metricResult');
			flagListenedTo.setAttribute('name','elementFlagListenedTo');
			flagListenedTo.textContent = this.wasListenedTo;
			storeDOM.push(flagListenedTo);
		}
		if (audioEngineContext.metric.enableFlagMoved) {
			var flagMoved = storage.document.createElement('metricResult');
			flagMoved.setAttribute('name','elementFlagMoved');
			flagMoved.textContent = this.wasMoved;
			storeDOM.push(flagMoved);
		}
		if (audioEngineContext.metric.enableFlagComments) {
			var flagComments = storage.document.createElement('metricResult');
			flagComments.setAttribute('name','elementFlagComments');
			if (this.parent.commentDOM == null)
				{flag.textContent = 'false';}
			else if (this.parent.commentDOM.textContent.length == 0) 
				{flag.textContent = 'false';}
			else 
				{flag.textContet = 'true';}
			storeDOM.push(flagComments);
		}
		return storeDOM;
	};
}

function randomiseOrder(input)
{
	// This takes an array of information and randomises the order
	var N = input.length;
	
	var inputSequence = []; // For safety purposes: keep track of randomisation
	for (var counter = 0; counter < N; ++counter) 
		inputSequence.push(counter) // Fill array
	var inputSequenceClone = inputSequence.slice(0);
	
	var holdArr = [];
	var outputSequence = [];
	for (var n=0; n<N; n++)
	{
		// First pick a random number
		var r = Math.random();
		// Multiply and floor by the number of elements left
		r = Math.floor(r*input.length);
		// Pick out that element and delete from the array
		holdArr.push(input.splice(r,1)[0]);
		// Do the same with sequence
		outputSequence.push(inputSequence.splice(r,1)[0]);
	}
	console.log(inputSequenceClone.toString()); // print original array to console
	console.log(outputSequence.toString()); 	// print randomised array to console
	return holdArr;
}

function returnDateNode()
{
	// Create an XML Node for the Date and Time a test was conducted
	// Structure is
	// <datetime> 
	//	<date year="##" month="##" day="##">DD/MM/YY</date>
	//	<time hour="##" minute="##" sec="##">HH:MM:SS</time>
	// </datetime>
	var dateTime = new Date();
	var year = document.createAttribute('year');
	var month = document.createAttribute('month');
	var day = document.createAttribute('day');
	var hour = document.createAttribute('hour');
	var minute = document.createAttribute('minute');
	var secs = document.createAttribute('secs');
	
	year.nodeValue = dateTime.getFullYear();
	month.nodeValue = dateTime.getMonth()+1;
	day.nodeValue = dateTime.getDate();
	hour.nodeValue = dateTime.getHours();
	minute.nodeValue = dateTime.getMinutes();
	secs.nodeValue = dateTime.getSeconds();
	
	var hold = document.createElement("datetime");
	var date = document.createElement("date");
	date.textContent = year.nodeValue+'/'+month.nodeValue+'/'+day.nodeValue;
	var time = document.createElement("time");
	time.textContent = hour.nodeValue+':'+minute.nodeValue+':'+secs.nodeValue;
	
	date.setAttributeNode(year);
	date.setAttributeNode(month);
	date.setAttributeNode(day);
	time.setAttributeNode(hour);
	time.setAttributeNode(minute);
	time.setAttributeNode(secs);
	
	hold.appendChild(date);
	hold.appendChild(time);
	return hold;
	
}

function Specification() {
	// Handles the decoding of the project specification XML into a simple JavaScript Object.
	
	this.interface = null;
	this.projectReturn = null;
	this.randomiseOrder = null;
	this.testPages = null;
	this.pages = [];
	this.metrics = null;
	this.interfaces = null;
	this.loudness = null;
	this.errors = [];
	this.schema = null;
	
	this.randomiseOrder = function(input)
	{
		// This takes an array of information and randomises the order
		var N = input.length;
		
		var inputSequence = []; // For safety purposes: keep track of randomisation
		for (var counter = 0; counter < N; ++counter) 
			inputSequence.push(counter) // Fill array
		var inputSequenceClone = inputSequence.slice(0);
		
		var holdArr = [];
		var outputSequence = [];
		for (var n=0; n<N; n++)
		{
			// First pick a random number
			var r = Math.random();
			// Multiply and floor by the number of elements left
			r = Math.floor(r*input.length);
			// Pick out that element and delete from the array
			holdArr.push(input.splice(r,1)[0]);
			// Do the same with sequence
			outputSequence.push(inputSequence.splice(r,1)[0]);
		}
		console.log(inputSequenceClone.toString()); // print original array to console
		console.log(outputSequence.toString()); 	// print randomised array to console
		return holdArr;
	};
	
	this.processAttribute = function(attribute,schema)
	{
		// attribute is the string returned from getAttribute on the XML
		// schema is the <xs:attribute> node
		if (schema.getAttribute('name') == undefined && schema.getAttribute('ref') != undefined)
		{
			schema = this.schema.getAllElementsByName(schema.getAttribute('ref'))[0];
		}
		var defaultOpt = schema.getAttribute('default');
		if (attribute == null) {
			attribute = defaultOpt;
		}
		var dataType = schema.getAttribute('type');
		if (typeof dataType == "string") { dataType = dataType.substr(3);}
		else {dataType = "string";}
		if (attribute == null)
		{
			return attribute;
		}
		switch(dataType)
		{
		case "boolean":
			if (attribute == 'true'){attribute = true;}else{attribute=false;}
			break;
		case "negativeInteger":
		case "positiveInteger":
		case "nonNegativeInteger":
		case "nonPositiveInteger":
		case "integer":
		case "decimal":
		case "short":
			attribute = Number(attribute);
			break;
		case "string":
		default:
			attribute = String(attribute);
			break;
		}
		return attribute;
	};
	
	this.decode = function(projectXML) {
		this.errors = [];
		// projectXML - DOM Parsed document
		this.projectXML = projectXML.childNodes[0];
		var setupNode = projectXML.getElementsByTagName('setup')[0];
		var schemaSetup = this.schema.getAllElementsByName('setup')[0];
		// First decode the attributes
		var attributes = schemaSetup.getAllElementsByTagName('xs:attribute');
		for (var i in attributes)
		{
			if (isNaN(Number(i)) == true){break;}
			var attributeName = attributes[i].getAttribute('name');
			var projectAttr = setupNode.getAttribute(attributeName);
			projectAttr = this.processAttribute(projectAttr,attributes[i]);
			switch(typeof projectAttr)
			{
			case "number":
			case "boolean":
				eval('this.'+attributeName+' = '+projectAttr);
				break;
			case "string":
				eval('this.'+attributeName+' = "'+projectAttr+'"');
				break;
			}
			
		}
		
		this.metrics = {
			enabled: [],
			decode: function(parent, xml) {
				var children = xml.getElementsByTagName('metricenable');
				for (var i in children) { 
					if (isNaN(Number(i)) == true){break;}
					this.enabled.push(children[i].textContent);
				}
			},
			encode: function(root) {
				var node = root.createElement('metric');
				for (var i in this.enabled)
				{
					if (isNaN(Number(i)) == true){break;}
					var child = root.createElement('metricenable');
					child.textContent = this.enabled[i];
					node.appendChild(child);
				}
				return node;
			}
		};
		
		this.metrics.decode(this,setupNode.getElementsByTagName('metric')[0]);
		
		// Now process the survey node options
		var survey = setupNode.getElementsByTagName('survey');
		var surveySchema = specification.schema.getAllElementsByName('survey')[0];
		for (var i in survey) {
			if (isNaN(Number(i)) == true){break;}
			var location = survey[i].getAttribute('location');
			if (location == 'pre' || location == 'before')
			{
				if (this.preTest != null){this.errors.push("Already a pre/before test survey defined! Ignoring second!!");}
				else {
					this.preTest = new this.surveyNode();
					this.preTest.decode(this,survey[i],surveySchema);
				}
			} else if (location == 'post' || location == 'after') {
				if (this.postTest != null){this.errors.push("Already a post/after test survey defined! Ignoring second!!");}
				else {
					this.postTest = new this.surveyNode();
					this.postTest.decode(this,survey[i],surveySchema);
				}
			}
		}
		
		var interfaceNode = setupNode.getElementsByTagName('interface');
		if (interfaceNode.length > 1)
		{
			this.errors.push("Only one <interface> node in the <setup> node allowed! Others except first ingnored!");
		}
		this.interfaces = new this.interfaceNode();
		if (interfaceNode.length != 0)
		{
			interfaceNode = interfaceNode[0];
			this.interfaces.decode(this,interfaceNode,this.schema.getAllElementsByName('interface')[1]);
		}
		
		// Page tags
		var pageTags = projectXML.getElementsByTagName('page');
		var pageSchema = this.schema.getAllElementsByName('page')[0];
		for (var i=0; i<pageTags.length; i++)
		{
			var node = new this.page();
			node.decode(this,pageTags[i],pageSchema);
			this.pages.push(node);
		}
	};
	
	this.encode = function()
	{
		var root = document.implementation.createDocument(null,"waet");
		
		// Build setup node
		
		return root;
	};
	
	this.surveyNode = function() {
		this.location = null;
		this.options = [];
		this.schema = null;
		
		this.OptionNode = function() {
			this.type = undefined;
			this.schema = undefined;
			this.id = undefined;
			this.mandatory = undefined;
			this.statement = undefined;
			this.boxsize = undefined;
			this.options = [];
			this.min = undefined;
			this.max = undefined;
			this.step = undefined;
			
			this.decode = function(parent,child,schema)
			{
				this.schema = schema;
				var attributeMap = schema.getAllElementsByTagName('xs:attribute');
				for (var i in attributeMap){
					if(isNaN(Number(i)) == true){break;}
					var attributeName = attributeMap[i].getAttribute('name') || attributeMap[i].getAttribute('ref');
					var projectAttr = child.getAttribute(attributeName);
					projectAttr = parent.processAttribute(projectAttr,attributeMap[i]);
					switch(typeof projectAttr)
					{
					case "number":
					case "boolean":
						eval('this.'+attributeName+' = '+projectAttr);
						break;
					case "string":
						eval('this.'+attributeName+' = "'+projectAttr+'"');
						break;
					}
				}
				this.statement = child.getElementsByTagName('statement')[0].textContent;
				if (this.type == "checkbox" || this.type == "radio") {
					var children = child.getElementsByTagName('option');
					if (children.length == null) {
						console.log('Malformed' +child.nodeName+ 'entry');
						this.statement = 'Malformed' +child.nodeName+ 'entry';
						this.type = 'statement';
					} else {
						this.options = [];
						for (var i in children)
						{
							if (isNaN(Number(i))==true){break;}
							this.options.push({
								name: children[i].getAttribute('name'),
								text: children[i].textContent
							});
						}
					}
				}
			};
			
			this.exportXML = function(root)
			{
				var node = root.createElement('surveyelement');
				node.setAttribute('type',this.type);
				var statement = root.createElement('statement');
				statement.textContent = this.statement;
				node.appendChild(statement);
				switch(this.type)
				{
				case "statement":
					break;
				case "question":
					node.id = this.id;
					node.setAttribute("mandatory",this.mandatory);
					node.setAttribute("boxsize",this.boxsize);
					break;
				case "number":
					node.id = this.id;
					node.setAttribute("mandatory",this.mandatory);
					node.setAttribute("min", this.min);
					node.setAttribute("max", this.max);
					node.setAttribute("step", this.step);
					break;
				case "checkbox":
				case "radio":
					node.id = this.id;
					for (var i=0; i<this.options.length; i++)
					{
						var option = this.options[i];
						var optionNode = root.createElement("option");
						optionNode.setAttribute("name",option.name);
						optionNode.textContent = option.text;
						node.appendChild(optionNode);
					}
					break;
				}
				return node;
			};
		};
		this.decode = function(parent,xml,schema) {
			this.schema = schema;
			this.location = xml.getAttribute('location');
			if (this.location == 'before'){this.location = 'pre';}
			else if (this.location == 'after'){this.location = 'post';}
			var surveyentrySchema = schema.getAllElementsByName('surveyentry')[0];
			for (var i in xml.children)
			{
				if(isNaN(Number(i))==true){break;}
				var node = new this.OptionNode();
				node.decode(parent,xml.children[i],surveyentrySchema);
				this.options.push(node);
			}
		};
		this.encode = function(root) {
			var node = root.createElement('survey');
			node.setAttribute('location',this.location);
			for (var i=0; i<this.options.length; i++)
			{
				node.appendChild(this.options[i].exportXML());
			}
			return node;
		};
	};
	
	this.interfaceNode = function()
	{
		this.title = null;
		this.name = null;
		this.options = [];
		this.scales = [];
		this.schema = null;
		
		this.decode = function(parent,xml,schema) {
			this.schema = schema;
			this.name = xml.getAttribute('name');
			var titleNode = xml.getElementsByTagName('title');
			if (titleNode.length == 1)
			{
				this.title = titleNode[0].textContent;
			}
			var interfaceOptionNodes = xml.getElementsByTagName('interfaceoption');
			// Extract interfaceoption node schema
			var interfaceOptionNodeSchema = schema.getAllElementsByName('interfaceoption')[0];
			var attributeMap = interfaceOptionNodeSchema.getAllElementsByTagName('xs:attribute');
			for (var i=0; i<interfaceOptionNodes.length; i++)
			{
				var ioNode = interfaceOptionNodes[i];
				var option = {};
				for (var j=0; j<attributeMap.length; j++)
				{
					var attributeName = attributeMap[j].getAttribute('name') || attributeMap[j].getAttribute('ref');
					var projectAttr = ioNode.getAttribute(attributeName);
					projectAttr = parent.processAttribute(projectAttr,attributeMap[j]);
					switch(typeof projectAttr)
					{
					case "number":
					case "boolean":
						eval('option.'+attributeName+' = '+projectAttr);
						break;
					case "string":
						eval('option.'+attributeName+' = "'+projectAttr+'"');
						break;
					}
				}
				this.options.push(option);
			}
			
			// Now the scales nodes
			var scaleParent = xml.getElementsByTagName('scales');
			if (scaleParent.length == 1) {
				scaleParent = scaleParent[0];
				for (var i=0; i<scaleParent.children.length; i++) {
					var child = scaleParent.children[i];
					this.scales.push({
						text: child.textContent,
						position: Number(child.getAttribute('position'))
					});
				}
			}
		};
		
		this.encode = function(root) {
			
		};
	};
	
	this.page = function() {
		this.presentedId = undefined;
		this.id = undefined;
		this.hostURL = undefined;
		this.randomiseOrder = undefined;
		this.loop = undefined;
		this.showElementComments = undefined;
		this.outsideReference = null;
		this.loudness = null;
		this.preTest = null;
		this.postTest = null;
		this.interfaces = [];
		this.commentBoxPrefix = "Comment on track";
		this.audioElements = [];
		this.commentQuestions = [];
		this.schema = null;
		
		this.decode = function(parent,xml,schema)
		{
			this.schema = schema;
			var attributeMap = this.schema.getAllElementsByTagName('xs:attribute');
			for (var i=0; i<attributeMap.length; i++)
			{
				var attributeName = attributeMap[i].getAttribute('name') || attributeMap[i].getAttribute('ref');
				var projectAttr = xml.getAttribute(attributeName);
				projectAttr = parent.processAttribute(projectAttr,attributeMap[i]);
				switch(typeof projectAttr)
				{
				case "number":
				case "boolean":
					eval('this.'+attributeName+' = '+projectAttr);
					break;
				case "string":
					eval('this.'+attributeName+' = "'+projectAttr+'"');
					break;
				}
			}
			
			// Get the Comment Box Prefix
			var CBP = xml.getElementsByTagName('commentboxprefix');
			if (CBP.length != 0) {
				this.commentBoxPrefix = CBP[0].textContent;
			}
			
			// Now decode the interfaces
			var interfaceNode = xml.getElementsByTagName('interface');
			for (var i=0; i<interfaceNode.length; i++)
			{
				var node = new parent.interfaceNode();
				node.decode(this,interfaceNode[i],parent.schema.getAllElementsByName('interface')[1]);
				this.interfaces.push(node);
			}
			
			// Now process the survey node options
			var survey = xml.getElementsByTagName('survey');
			var surveySchema = parent.schema.getAllElementsByName('survey')[0];
			for (var i in survey) {
				if (isNaN(Number(i)) == true){break;}
				var location = survey[i].getAttribute('location');
				if (location == 'pre' || location == 'before')
				{
					if (this.preTest != null){this.errors.push("Already a pre/before test survey defined! Ignoring second!!");}
					else {
						this.preTest = new parent.surveyNode();
						this.preTest.decode(parent,survey[i],surveySchema);
					}
				} else if (location == 'post' || location == 'after') {
					if (this.postTest != null){this.errors.push("Already a post/after test survey defined! Ignoring second!!");}
					else {
						this.postTest = new parent.surveyNode();
						this.postTest.decode(parent,survey[i],surveySchema);
					}
				}
			}
			
			// Now process the audioelement tags
			var audioElements = xml.getElementsByTagName('audioelement');
			var audioElementSchema = parent.schema.getAllElementsByName('audioelement')[0];
			for (var i=0; i<audioElements.length; i++)
			{
				var node = new this.audioElementNode();
				node.decode(this,audioElements[i],audioElementSchema);
				this.audioElements.push(node);
			}
			
			// Now decode the commentquestions
			var commentQuestions = xml.getElementsByTagName('commentquestion');
			var commentQuestionSchema = parent.schema.getAllElementsByName('commentquestion')[0];
			for (var i=0; i<commentQuestions.length; i++)
			{
				var node = new this.commentQuestionNode();
				node.decode(parent,commentQuestions[i],commentQuestionSchema);
				this.commentQuestions.push(node);
			}
		};
		
		this.encode = function(root)
		{
			var AHNode = root.createElement("audioHolder");
			AHNode.id = this.id;
			AHNode.setAttribute("hostURL",this.hostURL);
			AHNode.setAttribute("sampleRate",this.sampleRate);
			AHNode.setAttribute("randomiseOrder",this.randomiseOrder);
			AHNode.setAttribute("repeatCount",this.repeatCount);
			AHNode.setAttribute("loop",this.loop);
			AHNode.setAttribute("elementComments",this.elementComments);
			if(this.loudness != null) {AHNode.setAttribute("loudness",this.loudness);}
			if(this.initialPosition != null) {
				AHNode.setAttribute("loudness",this.initialPosition*100);
				}
			for (var i=0; i<this.interfaces.length; i++)
			{
				AHNode.appendChild(this.interfaces[i].encode(root));
			}
			
			for (var i=0; i<this.audioElements.length; i++) {
				AHNode.appendChild(this.audioElements[i].encode(root));
			}
			// Create <CommentQuestion>
			for (var i=0; i<this.commentQuestions.length; i++)
			{
				AHNode.appendChild(this.commentQuestions[i].exportXML(root));
			}
			
			// Create <PreTest>
			var AHPreTest = root.createElement("PreTest");
			for (var i=0; i<this.preTest.options.length; i++)
			{
				AHPreTest.appendChild(this.preTest.options[i].exportXML(root));
			}
			
			var AHPostTest = root.createElement("PostTest");
			for (var i=0; i<this.postTest.options.length; i++)
			{
				AHPostTest.appendChild(this.postTest.options[i].exportXML(root));
			}
			AHNode.appendChild(AHPreTest);
			AHNode.appendChild(AHPostTest);
			return AHNode;
		};
		
		this.commentQuestionNode = function() {
			this.id = null;
			this.type = undefined;
			this.options = [];
			this.statement = undefined;
			this.schema = null;
			this.decode = function(parent,xml,schema)
			{
				this.id = xml.id;
				this.type = xml.getAttribute('type');
				this.statement = xml.getElementsByTagName('statement')[0].textContent;
				var optNodes = xml.getElementsByTagName('option');
				for (var i=0; i<optNodes.length; i++)
				{
					var optNode = optNodes[i];
					this.options.push({
						name: optNode.getAttribute('name'),
						text: optNode.textContent
					});
				}
			};
			
			this.encode = function(root)
			{
				
			};
		};
		
		this.audioElementNode = function() {
			this.url = null;
			this.id = null;
			this.parent = null;
			this.type = null;
			this.marker = false;
			this.enforce = false;
			this.gain = 1.0;
			this.schema = null;
			this.parent = null;
			this.decode = function(parent,xml,schema)
			{
				this.schema = schema;
				this.parent = parent;
				var attributeMap = this.schema.getAllElementsByTagName('xs:attribute');
				for (var i=0; i<attributeMap.length; i++)
				{
					var attributeName = attributeMap[i].getAttribute('name') || attributeMap[i].getAttribute('ref');
					var projectAttr = xml.getAttribute(attributeName);
					projectAttr = specification.processAttribute(projectAttr,attributeMap[i]);
					switch(typeof projectAttr)
					{
					case "number":
					case "boolean":
						eval('this.'+attributeName+' = '+projectAttr);
						break;
					case "string":
						eval('this.'+attributeName+' = "'+projectAttr+'"');
						break;
					}
				}
				
			};
			this.encode = function(root)
			{
				var AENode = root.createElement("audioElements");
				AENode.id = this.id;
				AENode.setAttribute("url",this.url);
				AENode.setAttribute("type",this.type);
				AENode.setAttribute("gain",linearToDecibel(this.gain));
				if (this.marker != false)
				{
					AENode.setAttribute("marker",this.marker*100);
				}
				return AENode;
			};
		};
	};
}
			
function Interface(specificationObject) {
	// This handles the bindings between the interface and the audioEngineContext;
	this.specification = specificationObject;
	this.insertPoint = document.getElementById("topLevelBody");
	
	this.newPage = function(audioHolderObject,store)
	{
		audioEngineContext.newTestPage(store);
		audioEngineContext.loopPlayback = audioHolderObject.loop;
		// Delete any previous audioObjects associated with the audioEngine
		audioEngineContext.audioObjects = [];
		interfaceContext.deleteCommentBoxes();
		interfaceContext.deleteCommentQuestions();
		loadTest(audioHolderObject,store);
	};
	
	// Bounded by interface!!
	// Interface object MUST have an exportXMLDOM method which returns the various DOM levels
	// For example, APE returns  the slider position normalised in a <value> tag.
	this.interfaceObjects = [];
	this.interfaceObject = function(){};
	
	this.resizeWindow = function(event)
	{
		popup.resize(event);
		for(var i=0; i<this.commentBoxes.length; i++)
		{this.commentBoxes[i].resize();}
		for(var i=0; i<this.commentQuestions.length; i++)
		{this.commentQuestions[i].resize();}
		try
		{
			resizeWindow(event);
		}
		catch(err)
		{
			console.log("Warning - Interface does not have Resize option");
			console.log(err);
		}
	};
	
	this.returnNavigator = function()
	{
		var node = storage.document.createElement("navigator");
		var platform = storage.document.createElement("platform");
		platform.textContent = navigator.platform;
		var vendor = storage.document.createElement("vendor");
		vendor.textContent = navigator.vendor;
		var userAgent = storage.document.createElement("uagent");
		userAgent.textContent = navigator.userAgent;
        var screen = storage.document.createElement("window");
        screen.setAttribute('innerWidth',window.innerWidth);
        screen.setAttribute('innerHeight',window.innerHeight);
		node.appendChild(platform);
		node.appendChild(vendor);
		node.appendChild(userAgent);
        node.appendChild(screen);
		return node;
	};
	
	this.commentBoxes = [];
	this.elementCommentBox = function(audioObject) {
		var element = audioObject.specification;
		this.audioObject = audioObject;
		this.id = audioObject.id;
		var audioHolderObject = audioObject.specification.parent;
		// Create document objects to hold the comment boxes
		this.trackComment = document.createElement('div');
		this.trackComment.className = 'comment-div';
		this.trackComment.id = 'comment-div-'+audioObject.id;
		// Create a string next to each comment asking for a comment
		this.trackString = document.createElement('span');
		this.trackString.innerHTML = audioHolderObject.commentBoxPrefix+' '+audioObject.interfaceDOM.getPresentedId();
		// Create the HTML5 comment box 'textarea'
		this.trackCommentBox = document.createElement('textarea');
		this.trackCommentBox.rows = '4';
		this.trackCommentBox.cols = '100';
		this.trackCommentBox.name = 'trackComment'+audioObject.id;
		this.trackCommentBox.className = 'trackComment';
		var br = document.createElement('br');
		// Add to the holder.
		this.trackComment.appendChild(this.trackString);
		this.trackComment.appendChild(br);
		this.trackComment.appendChild(this.trackCommentBox);
		
		this.exportXMLDOM = function() {
			var root = document.createElement('comment');
			if (this.audioObject.specification.parent.elementComments) {
				var question = document.createElement('question');
				question.textContent = this.trackString.textContent;
				var response = document.createElement('response');
				response.textContent = this.trackCommentBox.value;
				console.log("Comment frag-"+this.id+": "+response.textContent);
				root.appendChild(question);
				root.appendChild(response);
			}
			return root;
		};
		this.resize = function()
		{
			var boxwidth = (window.innerWidth-100)/2;
			if (boxwidth >= 600)
			{
				boxwidth = 600;
			}
			else if (boxwidth < 400)
			{
				boxwidth = 400;
			}
			this.trackComment.style.width = boxwidth+"px";
			this.trackCommentBox.style.width = boxwidth-6+"px";
		};
		this.resize();
	};
	
	this.commentQuestions = [];
	
	this.commentBox = function(commentQuestion) {
		this.specification = commentQuestion;
		// Create document objects to hold the comment boxes
		this.holder = document.createElement('div');
		this.holder.className = 'comment-div';
		// Create a string next to each comment asking for a comment
		this.string = document.createElement('span');
		this.string.innerHTML = commentQuestion.statement;
		// Create the HTML5 comment box 'textarea'
		this.textArea = document.createElement('textarea');
		this.textArea.rows = '4';
		this.textArea.cols = '100';
		this.textArea.className = 'trackComment';
		var br = document.createElement('br');
		// Add to the holder.
		this.holder.appendChild(this.string);
		this.holder.appendChild(br);
		this.holder.appendChild(this.textArea);
		
		this.exportXMLDOM = function() {
			var root = document.createElement('comment');
			root.id = this.specification.id;
			root.setAttribute('type',this.specification.type);
			root.textContent = this.textArea.value;
			console.log("Question: "+this.string.textContent);
			console.log("Response: "+root.textContent);
			return root;
		};
		this.resize = function()
		{
			var boxwidth = (window.innerWidth-100)/2;
			if (boxwidth >= 600)
			{
				boxwidth = 600;
			}
			else if (boxwidth < 400)
			{
				boxwidth = 400;
			}
			this.holder.style.width = boxwidth+"px";
			this.textArea.style.width = boxwidth-6+"px";
		};
		this.resize();
	};
	
	this.radioBox = function(commentQuestion) {
		this.specification = commentQuestion;
		// Create document objects to hold the comment boxes
		this.holder = document.createElement('div');
		this.holder.className = 'comment-div';
		// Create a string next to each comment asking for a comment
		this.string = document.createElement('span');
		this.string.innerHTML = commentQuestion.statement;
		var br = document.createElement('br');
		// Add to the holder.
		this.holder.appendChild(this.string);
		this.holder.appendChild(br);
		this.options = [];
		this.inputs = document.createElement('div');
		this.span = document.createElement('div');
		this.inputs.align = 'center';
		this.inputs.style.marginLeft = '12px';
		this.span.style.marginLeft = '12px';
		this.span.align = 'center';
		this.span.style.marginTop = '15px';
		
		var optCount = commentQuestion.options.length;
		for (var optNode of commentQuestion.options)
		{
			var div = document.createElement('div');
			div.style.width = '80px';
			div.style.float = 'left';
			var input = document.createElement('input');
			input.type = 'radio';
			input.name = commentQuestion.id;
			input.setAttribute('setvalue',optNode.name);
			input.className = 'comment-radio';
			div.appendChild(input);
			this.inputs.appendChild(div);
			
			
			div = document.createElement('div');
			div.style.width = '80px';
			div.style.float = 'left';
			div.align = 'center';
			var span = document.createElement('span');
			span.textContent = optNode.text;
			span.className = 'comment-radio-span';
			div.appendChild(span);
			this.span.appendChild(div);
			this.options.push(input);
		}
		this.holder.appendChild(this.span);
		this.holder.appendChild(this.inputs);
		
		this.exportXMLDOM = function() {
			var root = document.createElement('comment');
			root.id = this.specification.id;
			root.setAttribute('type',this.specification.type);
			var question = document.createElement('question');
			question.textContent = this.string.textContent;
			var response = document.createElement('response');
			var i=0;
			while(this.options[i].checked == false) {
				i++;
				if (i >= this.options.length) {
					break;
				}
			}
			if (i >= this.options.length) {
				response.textContent = 'null';
			} else {
				response.textContent = this.options[i].getAttribute('setvalue');
				response.setAttribute('number',i);
			}
			console.log('Comment: '+question.textContent);
			console.log('Response: '+response.textContent);
			root.appendChild(question);
			root.appendChild(response);
			return root;
		};
		this.resize = function()
		{
			var boxwidth = (window.innerWidth-100)/2;
			if (boxwidth >= 600)
			{
				boxwidth = 600;
			}
			else if (boxwidth < 400)
			{
				boxwidth = 400;
			}
			this.holder.style.width = boxwidth+"px";
			var text = this.holder.children[2];
			var options = this.holder.children[3];
			var optCount = options.children.length;
			var spanMargin = Math.floor(((boxwidth-20-(optCount*80))/(optCount))/2)+'px';
			var options = options.firstChild;
			var text = text.firstChild;
			options.style.marginRight = spanMargin;
			options.style.marginLeft = spanMargin;
			text.style.marginRight = spanMargin;
			text.style.marginLeft = spanMargin;
			while(options.nextSibling != undefined)
			{
				options = options.nextSibling;
				text = text.nextSibling;
				options.style.marginRight = spanMargin;
				options.style.marginLeft = spanMargin;
				text.style.marginRight = spanMargin;
				text.style.marginLeft = spanMargin;
			}
		};
		this.resize();
	};
	
	this.checkboxBox = function(commentQuestion) {
		this.specification = commentQuestion;
		// Create document objects to hold the comment boxes
		this.holder = document.createElement('div');
		this.holder.className = 'comment-div';
		// Create a string next to each comment asking for a comment
		this.string = document.createElement('span');
		this.string.innerHTML = commentQuestion.statement;
		var br = document.createElement('br');
		// Add to the holder.
		this.holder.appendChild(this.string);
		this.holder.appendChild(br);
		this.options = [];
		this.inputs = document.createElement('div');
		this.span = document.createElement('div');
		this.inputs.align = 'center';
		this.inputs.style.marginLeft = '12px';
		this.span.style.marginLeft = '12px';
		this.span.align = 'center';
		this.span.style.marginTop = '15px';
		
		var optCount = commentQuestion.options.length;
		for (var i=0; i<optCount; i++)
		{
			var div = document.createElement('div');
			div.style.width = '80px';
			div.style.float = 'left';
			var input = document.createElement('input');
			input.type = 'checkbox';
			input.name = commentQuestion.id;
			input.setAttribute('setvalue',commentQuestion.options[i].name);
			input.className = 'comment-radio';
			div.appendChild(input);
			this.inputs.appendChild(div);
			
			
			div = document.createElement('div');
			div.style.width = '80px';
			div.style.float = 'left';
			div.align = 'center';
			var span = document.createElement('span');
			span.textContent = commentQuestion.options[i].text;
			span.className = 'comment-radio-span';
			div.appendChild(span);
			this.span.appendChild(div);
			this.options.push(input);
		}
		this.holder.appendChild(this.span);
		this.holder.appendChild(this.inputs);
		
		this.exportXMLDOM = function() {
			var root = document.createElement('comment');
			root.id = this.specification.id;
			root.setAttribute('type',this.specification.type);
			var question = document.createElement('question');
			question.textContent = this.string.textContent;
			root.appendChild(question);
			console.log('Comment: '+question.textContent);
			for (var i=0; i<this.options.length; i++) {
				var response = document.createElement('response');
				response.textContent = this.options[i].checked;
				response.setAttribute('name',this.options[i].getAttribute('setvalue'));
				root.appendChild(response);
				console.log('Response '+response.getAttribute('name') +': '+response.textContent);
			}
			return root;
		};
		this.resize = function()
		{
			var boxwidth = (window.innerWidth-100)/2;
			if (boxwidth >= 600)
			{
				boxwidth = 600;
			}
			else if (boxwidth < 400)
			{
				boxwidth = 400;
			}
			this.holder.style.width = boxwidth+"px";
			var text = this.holder.children[2];
			var options = this.holder.children[3];
			var optCount = options.children.length;
			var spanMargin = Math.floor(((boxwidth-20-(optCount*80))/(optCount))/2)+'px';
			var options = options.firstChild;
			var text = text.firstChild;
			options.style.marginRight = spanMargin;
			options.style.marginLeft = spanMargin;
			text.style.marginRight = spanMargin;
			text.style.marginLeft = spanMargin;
			while(options.nextSibling != undefined)
			{
				options = options.nextSibling;
				text = text.nextSibling;
				options.style.marginRight = spanMargin;
				options.style.marginLeft = spanMargin;
				text.style.marginRight = spanMargin;
				text.style.marginLeft = spanMargin;
			}
		};
		this.resize();
	};

	this.createCommentBox = function(audioObject) {
		var node = new this.elementCommentBox(audioObject);
		this.commentBoxes.push(node);
		audioObject.commentDOM = node;
		return node;
	};
	
	this.sortCommentBoxes = function() {
		this.commentBoxes.sort(function(a,b){return a.id - b.id;});
	};
	
	this.showCommentBoxes = function(inject, sort) {
		if (sort) {interfaceContext.sortCommentBoxes();}
		for (var box of interfaceContext.commentBoxes) {
			inject.appendChild(box.trackComment);
		}
	};
	
	this.deleteCommentBoxes = function() {
		this.commentBoxes = [];
	};
	
	this.createCommentQuestion = function(element) {
		var node;
		if (element.type == 'question') {
			node = new this.commentBox(element);
		} else if (element.type == 'radio') {
			node = new this.radioBox(element);
		} else if (element.type == 'checkbox') {
			node = new this.checkboxBox(element);
		}
		this.commentQuestions.push(node);
		return node;
	};
	
	this.deleteCommentQuestions = function()
	{
		this.commentQuestions = [];
	};
	
	this.playhead = new function()
	{
		this.object = document.createElement('div');
		this.object.className = 'playhead';
		this.object.align = 'left';
		var curTime = document.createElement('div');
		curTime.style.width = '50px';
		this.curTimeSpan = document.createElement('span');
		this.curTimeSpan.textContent = '00:00';
		curTime.appendChild(this.curTimeSpan);
		this.object.appendChild(curTime);
		this.scrubberTrack = document.createElement('div');
		this.scrubberTrack.className = 'playhead-scrub-track';
		
		this.scrubberHead = document.createElement('div');
		this.scrubberHead.id = 'playhead-scrubber';
		this.scrubberTrack.appendChild(this.scrubberHead);
		this.object.appendChild(this.scrubberTrack);
		
		this.timePerPixel = 0;
		this.maxTime = 0;
		
		this.playbackObject;
		
		this.setTimePerPixel = function(audioObject) {
			//maxTime must be in seconds
			this.playbackObject = audioObject;
			this.maxTime = audioObject.buffer.buffer.duration;
			var width = 490; //500 - 10, 5 each side of the tracker head
			this.timePerPixel = this.maxTime/490;
			if (this.maxTime < 60) {
				this.curTimeSpan.textContent = '0.00';
			} else {
				this.curTimeSpan.textContent = '00:00';
			}
		};
		
		this.update = function() {
			// Update the playhead position, startPlay must be called
			if (this.timePerPixel > 0) {
				var time = this.playbackObject.getCurrentPosition();
				if (time > 0) {
					var width = 490;
					var pix = Math.floor(time/this.timePerPixel);
					this.scrubberHead.style.left = pix+'px';
					if (this.maxTime > 60.0) {
						var secs = time%60;
						var mins = Math.floor((time-secs)/60);
						secs = secs.toString();
						secs = secs.substr(0,2);
						mins = mins.toString();
						this.curTimeSpan.textContent = mins+':'+secs;
					} else {
						time = time.toString();
						this.curTimeSpan.textContent = time.substr(0,4);
					}
				} else {
					this.scrubberHead.style.left = '0px';
					if (this.maxTime < 60) {
						this.curTimeSpan.textContent = '0.00';
					} else {
						this.curTimeSpan.textContent = '00:00';
					}
				}
			}
		};
		
		this.interval = undefined;
		
		this.start = function() {
			if (this.playbackObject != undefined && this.interval == undefined) {
				if (this.maxTime < 60) {
					this.interval = setInterval(function(){interfaceContext.playhead.update();},10);
				} else {
					this.interval = setInterval(function(){interfaceContext.playhead.update();},100);
				}
			}
		};
		this.stop = function() {
			clearInterval(this.interval);
			this.interval = undefined;
			if (this.maxTime < 60) {
				this.curTimeSpan.textContent = '0.00';
			} else {
				this.curTimeSpan.textContent = '00:00';
			}
		};
	};
    
    this.volume = new function()
    {
        // An in-built volume module which can be viewed on page
        // Includes trackers on page-by-page data
        // Volume does NOT reset to 0dB on each page load
        this.valueLin = 1.0;
        this.valueDB = 0.0;
        this.object = document.createElement('div');
        this.object.id = 'master-volume-holder';
        this.slider = document.createElement('input');
        this.slider.id = 'master-volume-control';
        this.slider.type = 'range';
        this.valueText = document.createElement('span');
        this.valueText.id = 'master-volume-feedback';
        this.valueText.textContent = '0dB';
        
        this.slider.min = -60;
        this.slider.max = 12;
        this.slider.value = 0;
        this.slider.step = 1;
        this.slider.onmousemove = function(event)
        {
            interfaceContext.volume.valueDB = event.currentTarget.value;
            interfaceContext.volume.valueLin = decibelToLinear(interfaceContext.volume.valueDB);
            interfaceContext.volume.valueText.textContent = interfaceContext.volume.valueDB+'dB';
            audioEngineContext.outputGain.gain.value = interfaceContext.volume.valueLin;
        }
        this.slider.onmouseup = function(event)
        {
            var storePoint = testState.currentStore.XMLDOM.children[0].getAllElementsByName('volumeTracker');
            if (storePoint.length == 0)
            {
                storePoint = storage.document.createElement('metricresult');
                storePoint.setAttribute('name','volumeTracker');
                testState.currentStore.XMLDOM.children[0].appendChild(storePoint);
            }
            else {
                storePoint = storePoint[0];
            }
            var node = storage.document.createElement('movement');
            node.setAttribute('test-time',audioEngineContext.timer.getTestTime());
            node.setAttribute('volume',interfaceContext.volume.valueDB);
            node.setAttribute('format','dBFS');
            storePoint.appendChild(node);
        }
        
        var title = document.createElement('div');
        title.innerHTML = '<span>Master Volume Control</span>';
        title.style.fontSize = '0.75em';
        title.style.width = "100%";
        title.align = 'center';
        this.object.appendChild(title);
        
        this.object.appendChild(this.slider);
        this.object.appendChild(this.valueText);
    }
	// Global Checkers
	// These functions will help enforce the checkers
	this.checkHiddenAnchor = function()
	{
		for (var ao of audioEngineContext.audioObjects)
		{
			if (ao.specification.type == "anchor")
			{
				if (ao.interfaceDOM.getValue() > (ao.specification.marker/100) && ao.specification.marker > 0) {
					// Anchor is not set below
					console.log('Anchor node not below marker value');
					alert('Please keep listening');
					return false;
				}
			}
		}
		return true;
	};
	
	this.checkHiddenReference = function()
	{
		for (var ao of audioEngineContext.audioObjects)
		{
			if (ao.specification.type == "reference")
			{
				if (ao.interfaceDOM.getValue() < (ao.specification.marker/100) && ao.specification.marker > 0) {
					// Anchor is not set below
					console.log('Reference node not below marker value');
					alert('Please keep listening');
					return false;
				}
			}
		}
		return true;
	};
	
	this.checkFragmentsFullyPlayed = function ()
	{
		// Checks the entire file has been played back
		// NOTE ! This will return true IF playback is Looped!!!
		if (audioEngineContext.loopPlayback)
		{
			console.log("WARNING - Looped source: Cannot check fragments are fully played");
			return true;
		}
		var check_pass = true;
		var error_obj = [];
		for (var i = 0; i<audioEngineContext.audioObjects.length; i++)
		{
			var object = audioEngineContext.audioObjects[i];
			var time = object.buffer.buffer.duration;
			var metric = object.metric;
			var passed = false;
			for (var j=0; j<metric.listenTracker.length; j++)
			{
				var bt = metric.listenTracker[j].getElementsByTagName('buffertime');
				var start_time = Number(bt[0].getAttribute('start'));
				var stop_time = Number(bt[0].getAttribute('stop'));
				var delta = stop_time - start_time;
				if (delta >= time)
				{
					passed = true;
					break;
				}
			}
			if (passed == false)
			{
				check_pass = false;
				console.log("Continue listening to track-"+audioEngineContext.audioObjects.interfaceDOM.getPresentedId());
				error_obj.push(audioEngineContext.audioObjects.interfaceDOM.getPresentedId());
			}
		}
		if (check_pass == false)
		{
			var str_start = "You have not completely listened to fragments ";
			for (var i=0; i<error_obj.length; i++)
			{
				str_start += error_obj[i];
				if (i != error_obj.length-1)
				{
					str_start += ', ';
				}
			}
			str_start += ". Please keep listening";
			console.log("[ALERT]: "+str_start);
			alert(str_start);
		}
	};
	this.checkAllMoved = function()
	{
		var str = "You have not moved ";
		var failed = [];
		for (var ao of audioEngineContext.audioObjects)
		{
			if(ao.metric.wasMoved == false && ao.interfaceDOM.canMove() == true)
			{
				failed.push(ao.interfaceDOM.getPresentedId());
			}
		}
		if (failed.length == 0)
		{
			return true;
		} else if (failed.length == 1)
		{
			str += 'track '+failed[0];
		} else {
			str += 'tracks ';
			for (var i=0; i<failed.length-1; i++)
			{
				str += failed[i]+', ';
			}
			str += 'and '+failed[i];
		}
		str +='.';
		alert(str);
		console.log(str);
		return false;
	};
	this.checkAllPlayed = function()
	{
		var str = "You have not played ";
		var failed = [];
		for (var ao of audioEngineContext.audioObjects)
		{
			if(ao.metric.wasListenedTo == false)
			{
				failed.push(ao.interfaceDOM.getPresentedId());
			}
		}
		if (failed.length == 0)
		{
			return true;
		} else if (failed.length == 1)
		{
			str += 'track '+failed[0];
		} else {
			str += 'tracks ';
			for (var i=0; i<failed.length-1; i++)
			{
				str += failed[i]+', ';
			}
			str += 'and '+failed[i];
		}
		str +='.';
		alert(str);
		console.log(str);
		return false;
	};
}

function Storage()
{
	// Holds results in XML format until ready for collection
	this.globalPreTest = null;
	this.globalPostTest = null;
	this.testPages = [];
	this.document = document.implementation.createDocument(null,"waetresult");
	this.root = this.document.children[0];
	this.state = 0;
	
	this.initialise = function()
	{
		if (specification.preTest != undefined){this.globalPreTest = new this.surveyNode(this,this.root,specification.preTest);}
		if (specification.postTest != undefined){this.globalPostTest = new this.surveyNode(this,this.root,specification.postTest);}
	};
	
	this.createTestPageStore = function(specification)
	{
		var store = new this.pageNode(this,specification);
		this.testPages.push(store);
		return this.testPages[this.testPages.length-1];
	};
	
	this.surveyNode = function(parent,root,specification)
	{
		this.specification = specification;
		this.parent = parent;
		this.XMLDOM = this.parent.document.createElement('survey');
		this.XMLDOM.setAttribute('location',this.specification.location);
		for (var optNode of this.specification.options)
		{
			if (optNode.type != 'statement')
			{
				var node = this.parent.document.createElement('surveyresult');
				node.id = optNode.id;
				node.setAttribute('type',optNode.type);
				this.XMLDOM.appendChild(node);
			}
		}
		root.appendChild(this.XMLDOM);
		
		this.postResult = function(node)
		{
			// From popup: node is the popupOption node containing both spec. and results
			// ID is the position
			if (node.specification.type == 'statement'){return;}
			var surveyresult = this.parent.document.getElementById(node.specification.id);
			switch(node.specification.type)
			{
			case "number":
			case "question":
				var child = this.parent.document.createElement('response');
				child.textContent = node.response;
				surveyresult.appendChild(child);
				break;
			case "radio":
				var child = this.parent.document.createElement('response');
				child.setAttribute('name',node.response.name);
				child.textContent = node.response.text;
				surveyresult.appendChild(child);
				break;
			case "checkbox":
				for (var i=0; i<node.response.length; i++)
				{
					var checkNode = this.parent.document.createElement('response');
					checkNode.setAttribute('name',node.response[i].name);
					checkNode.setAttribute('checked',node.response[i].checked);
					surveyresult.appendChild(checkNode);
				}
				break;
			}
		};
	};
	
	this.pageNode = function(parent,specification)
	{
		// Create one store per test page
		this.specification = specification;
		this.parent = parent;
		this.XMLDOM = this.parent.document.createElement('page');
		this.XMLDOM.setAttribute('id',specification.id);
		this.XMLDOM.setAttribute('presentedId',specification.presentedId);
		if (specification.preTest != undefined){this.preTest = new this.parent.surveyNode(this.parent,this.XMLDOM,this.specification.preTest);}
		if (specification.postTest != undefined){this.postTest = new this.parent.surveyNode(this.parent,this.XMLDOM,this.specification.postTest);}
		
		// Add any page metrics
		var page_metric = this.parent.document.createElement('metric');
		this.XMLDOM.appendChild(page_metric);
		
		// Add the audioelement
		for (var element of this.specification.audioElements)
		{
			var aeNode = this.parent.document.createElement('audioelement');
			aeNode.id = element.id;
			aeNode.setAttribute('type',element.type);
			aeNode.setAttribute('url', element.url);
			aeNode.setAttribute('gain', element.gain);
			if (element.type == 'anchor' || element.type == 'reference')
			{
				if (element.marker > 0)
				{
					aeNode.setAttribute('marker',element.marker);
				}
			}
			var ae_metric = this.parent.document.createElement('metric');
			aeNode.appendChild(ae_metric); 
			this.XMLDOM.appendChild(aeNode);
		}
		
		// Add any commentQuestions
		for (var element of this.specification.commentQuestions)
		{
			var cqNode = this.parent.document.createElement('commentquestion');
			cqNode.id = element.id;
			cqNode.setAttribute('type',element.type);
			var statement = this.parent.document.createElement('statement');
			statement.textContent = cqNode.statement;
			cqNode.appendChild(statement);
			var response = this.parent.document.createElement('response');
			cqNode.appendChild(response);
			this.XMLDOM.appendChild(cqNode);
		}
		
		this.parent.root.appendChild(this.XMLDOM);
	};
	this.finish = function()
	{
		if (this.state == 0)
		{
			var projectDocument = specification.projectXML;
			projectDocument.setAttribute('file-name',url);
			this.root.appendChild(projectDocument);
			this.root.appendChild(returnDateNode());
			this.root.appendChild(interfaceContext.returnNavigator());
		}
		this.state = 1;
		return this.root;
	};
}