Changed GUI to be instanceable (rather than just one GUI per project). GUI.start() is now var gui = new GUI();

Included prettify.js in the repo so people checking the demo localy doesn't need the internets.
Changed way of hidding the panel (controllerContainer.style.height rather than this.domElement.stylemarginTop).

controllers/controller.js

@@ -2,6 +2,8 @@ var Controller = function() {
 
 	var onChange = null;
 
+	this.parent = null;
+
 	this.setName = function(n) {
 	    this.propertyNameElement.innerHTML = n;
 	    return this;

controllers/controller.number.js

@@ -70,7 +70,7 @@ var NumberController = function() {
     
     document.addEventListener('mouseup', function(e) {
         document.removeEventListener('mousemove', dragNumberField, false);
-        _this.makeSelectable(GUI.domElement); 
+        _this.makeSelectable(_this.parent.domElement); 
         _this.makeSelectable(numberField);
         if (clickedNumberField && !draggedNumberField) { 
 	        numberField.focus();

gui.js

@@ -1,60 +1,28 @@
-var GUI = new function() {
+var GUI = function () {
 
-	var _this = this;
+	var _this = this, open = false,
+	controllers = [], controllersWatched = [];
 
-	var controllers = [];
+	this.domElement = document.createElement('div');
+	this.domElement.setAttribute('id', 'guidat');
 
-	this.add = function() {
+	controllerContainer = document.createElement('div');
+	controllerContainer.setAttribute('id', 'guidat-controllers');
+	controllerContainer.style.height = '0px';
 
-		// We need to call GUI.start() before .add()
+	toggleButton = document.createElement('a');
-		if (!started) {
+	toggleButton.setAttribute('id', 'guidat-toggle');
-			error("Make sure to call GUI.start() in the window.onload function");
+	toggleButton.setAttribute('href', '#');
-			return;
+	toggleButton.innerHTML = "Show Controls";
-		}
+	toggleButton.addEventListener('click', function(e) {
+		_this.toggle();
+		e.preventDefault();
+	}, false);
 
-		var object = arguments[0];
+	this.domElement.appendChild(controllerContainer);
-		var propertyName = arguments[1];
+	this.domElement.appendChild(toggleButton);
 
-		// Have we already added this?
+	var handlerTypes = {
-		if (alreadyControlled(object, propertyName)) {
-			error("Controller for \"" + propertyName+"\" already added.");
-			return;
-		}
-	
-		var value = object[propertyName];
-		
-		// Does this value exist? Is it accessible?
-		if (value == undefined) {
-			error(object + " either has no property \""+propertyName+"\", or the property is inaccessible.");
-			return;
-		}
-		
-		var type = typeof value;
-		var handler = addHandlers[type];
-		
-		// Do we know how to deal with this data type?
-		if (handler == undefined) {
-			error("Cannot create controller for data type \""+type+"\"");
-			return;
-		}
-	
-		var controllerObject = construct(handler, arguments);
-		
-		// Were we able to make the controller?
-		if (!controllerObject) {		
-			error("Error creating controller for \""+propertyName+"\".");	
-			return;
-		}
-		
-		// Success.
-		controllerContainer.appendChild(controllerObject.domElement);
-		controllers.push(controllerObject);
-		
-		return controllerObject;
-		
-	}
-	
-	var addHandlers = {
 		"number": NumberController,
 		"string": StringController,
 		"boolean": BooleanController,
@@ -85,45 +53,50 @@ var GUI = new function() {
 		return new F();
 	};
 
+	this.add = function() {
 
+		var object = arguments[0];
+		var propertyName = arguments[1];
 
-	// GUI ... GUI
+		// Have we already added this?
+		if (alreadyControlled(object, propertyName)) {
+			error("Controller for \"" + propertyName+"\" already added.");
+			return;
+		}
 
-	this.domElement = null;
+		var value = object[propertyName];
-	var controllerContainer;
-	var started = false;
-	var open = false;
 
-	// TODO: obtain this dynamically?
+		// Does this value exist? Is it accessible?
-	var domElementMarginTop = 300;
+		if (value == undefined) {
+			error(object + " either has no property \""+propertyName+"\", or the property is inaccessible.");
+			return;
+		}
 
-	this.start = function() {
+		var type = typeof value;
+		var handler = handlerTypes[type];
 
-		this.domElement = document.createElement('div');
+		// Do we know how to deal with this data type?
-		this.domElement.setAttribute('id', 'guidat');
+		if (handler == undefined) {
+			error("Cannot create controller for data type \""+type+"\"");
+			return;
+		}
 
-		controllerContainer = document.createElement('div');
+		var controllerObject = construct( handler, arguments);
-		controllerContainer.setAttribute('id', 'guidat-controllers');
+		controllerObject.parent = _this;
 
-		toggleButton = document.createElement('a');
+		// Were we able to make the controller?
-		toggleButton.setAttribute('id', 'guidat-toggle');
+		if (!controllerObject) {
-		toggleButton.setAttribute('href', '#');
+			error("Error creating controller for \""+propertyName+"\".");
-		toggleButton.innerHTML = "Show Controls";
+			return;
-		toggleButton.addEventListener('click', function(e) {
+		}
-			_this.toggle();
-			e.preventDefault();
-		}, false);
 
-		this.domElement.appendChild(controllerContainer);
+		// Success.
-		this.domElement.appendChild(toggleButton);
+		controllerContainer.appendChild(controllerObject.domElement);
+		controllers.push(controllerObject);
 
-		this.domElement.style.marginTop = -domElementMarginTop+"px";
+		return controllerObject;
 
-		document.body.appendChild(this.domElement);
+	}
-		
-		started = true;
-		
-	};
 
 	this.toggle = function() {
 
@@ -136,13 +109,13 @@ var GUI = new function() {
 	};
 
 	this.show = function() {
-		this.domElement.style.marginTop = 0+"px";
+		controllerContainer.style.height = '300px';
 		toggleButton.innerHTML = "Hide Controls";
 		open = true;
 	}
 
 	this.hide = function() {
-		this.domElement.style.marginTop = -domElementMarginTop+"px";
+		controllerContainer.style.height = '0px';
 		toggleButton.innerHTML = "Show Controls";
 		open = false;
 	}

index.html

@@ -4,9 +4,21 @@
 
         <link rel="icon" type="image/png" href="demo/assets/favicon.png" />
         <link href="demo/demo.css" media="screen" rel="stylesheet" type="text/css" />
-        <script type="text/javascript" src="http://google-code-prettify.googlecode.com/svn/trunk/src/prettify.js"></script>
+
-        <script type="text/javascript" src="gui.min.js"></script>
+	<!-- <script type="text/javascript" src="gui.min.js"></script> -->
+
+	<link href="gui.css" media="screen" rel="stylesheet" type="text/css" />
+
+	<script type="text/javascript" src="controllers/slider.js"></script>
+	<script type="text/javascript" src="controllers/controller.js"></script>
+	<script type="text/javascript" src="controllers/controller.boolean.js"></script>
+	<script type="text/javascript" src="controllers/controller.function.js"></script>
+	<script type="text/javascript" src="controllers/controller.number.js"></script>
+	<script type="text/javascript" src="controllers/controller.string.js"></script>
+	<script type="text/javascript" src="gui.js"></script>
+
         <script type="text/javascript" src="demo/improvedNoise.js"></script>
+        <script type="text/javascript" src="demo/prettify.js"></script>
         <script type="text/javascript" src="demo/demo.js"></script>
         <script type="text/javascript">
             window.onload = function() {
@@ -15,25 +27,25 @@
 
 		var fizzyText = new FizzyText("gui-dat");
 
-               GUI.start();
+		var gui = new GUI();
+		document.body.appendChild( gui.domElement );
 
 		// Text field
-               GUI.add(fizzyText, "message");
+		gui.add(fizzyText, "message");
 
 		// Sliders with min and max
-               GUI.add(fizzyText, "maxSize", 0.5, 7);
+		gui.add(fizzyText, "maxSize", 0.5, 7);
-               GUI.add(fizzyText, "growthSpeed", 0.01, 1);
+		gui.add(fizzyText, "growthSpeed", 0.01, 1);
-               GUI.add(fizzyText, "speed", 0.1, 2);
+		gui.add(fizzyText, "speed", 0.1, 2);
 
 		// Sliders with min, max and increment.
-               GUI.add(fizzyText, "noiseStrength", 10, 100, 5);
+		gui.add(fizzyText, "noiseStrength", 10, 100, 5);
 
 		// Boolean checkbox
-               GUI.add(fizzyText, "displayOutline");
+		gui.add(fizzyText, "displayOutline");
 
 		// Fires a function called "explode"
-               GUI.add(fizzyText, "explode")
+		gui.add(fizzyText, "explode").setName('Explode!');    // Specify a custom name.
-                    .setName('Explode!');    // Specify a custom name.
 
             };
 
@@ -49,7 +61,6 @@
         </script>
     </head>
     <body>
-    	<div id="container">
 	    <div id = "helvetica-demo"></div>
 	    <div id = "notifier"></div>
         <h1><a href = "http://twitter.com/guidat"><img src = "demo/assets/profile.png" border = "0" alt = "GUI-DAT flag" /></a></h1>
@@ -63,7 +74,7 @@
         </ul>
 
         <h2>Basic Usage</h2>
-        <pre class="prettyprint">&lt;script type=&quot;text/javascript&quot; src=&quot;demo/demo.js&quot;&gt;&lt;/script&gt;
+        <pre id="demo-pre" class="prettyprint">&lt;script type=&quot;text/javascript&quot; src=&quot;demo/demo.js&quot;&gt;&lt;/script&gt;
 &lt;script type=&quot;text/javascript&quot;&gt;
 
 window.onload = function() {
@@ -80,14 +91,14 @@ window.onload = function() {
    GUI.add(fizzyText, &quot;growthSpeed&quot;, 0.01, 1);
    GUI.add(fizzyText, &quot;speed&quot;, 0.1, 2);
 
-   // Sliders with min, max and increment
+   // Sliders with min, max and increment.
    GUI.add(fizzyText, &quot;noiseStrength&quot;, 10, 100, 5);
 
    // Boolean checkbox
    GUI.add(fizzyText, &quot;displayOutline&quot;);
 
    // Fires a function called &quot;explode&quot;
-   GUI.add(fizzyText, &quot;explode&quot;).setName(&quot;Explode!&quot;); // Specify a custom name.
+   GUI.add(fizzyText, &quot;explode&quot;).setName(&#039;Explode!&#039;); // Specify a custom name.
 
 };
 
@@ -97,20 +108,8 @@ window.onload = function() {
     		<li><strong>gui-dat</strong> will infer the type of the property you're trying to add<br/>(based on its initial value) and create the corresponding control.</li>
     		<li>The properties must be public, i.e. defined by <code><strong>this</strong>.prop = value</code>.</li>
     	</ul>
-    	<!--
-		<hr/>
-    	<h2>Monitor variable changes <em>outside</em> of the GUI</h2>
-    	<p>Let's say you have a variable that changes by itself from time to time. If you'd like the GUI to reflect those changes, use the <code>listen()</code> method.</p>
-    	<pre class="prettyprint">GUI.add(obj, "propName").listen();</pre>
-
-    	<h2>Fire a function when someone uses a control</h2>
-    	<pre class="prettyprint">GUI.add(obj, "propName").onChange(function(n) {
-	alert("You changed me to " + n);
-});</pre>
--->
 		<footer>
-            Initiated by <a href="http://georgemichaelbrower.com/">George Michael Brower</a> and <a href="http://jonobr1.com/">Jono Brandel</a> of the Data Arts Team, Google Creative Lab.
+            By <a href="http://georgemichaelbrower.com/">George Michael Brower</a>, <a href="http://jonobr1.com/">Jono Brandel</a>, and <a href="http://github.com/jonobr1/GUI-DAT">you</a>.
         </footer>
-		</div>
     </body>
 </html>