// Scrollbar
// from http://greghoustondesign.com/examples/mootools/scrollbars/

/* Call into html doc like:

// Place script below markup!!!
<script type="text/javascript">

		var scr = new ScrollBar('scrollmain', 'scrollcontent');
		var scr2 = new ScrollBar('scrollmain2', 'scrollcontent2', {
			'arrows': false,
			'hScroll': false
        });
		
		new Drag('scrollcontent', {
			'modifiers': {y: 'height', x: 'width'},
			'limit': { x:[100], y:[50] },			
			onDrag: function(){
				scr.update();
			}
		});
		
		new Drag('scrollcontent2', {
			'modifiers': {y: 'height', x: 'width'},
			'limit': { x:[100], y:[50] },			
			onDrag: function(){
				scr2.update();
			}
		});		

	</script>
	
with these styles:

<style type="text/css" media="screen">

#scrollmain, #scrollmain2 {
	width: 320px;
	height: 225px;
	border: 1px solid #111;
	background: #ff3300;
}
#scrollcontent, #scrollcontent2 {
	width: 320px;
	height: 225px;
	float: left;
	overflow: hidden;
	color: #fff;
}
.text {
	margin: 10px;
}
.vScrollbar {
	float: left;
}
.hScrollbar {
	clear: both;
}
.vTrack {
	height: 300px;
	width: 15px;
	position: relative;
	background: #ddd;
	overflow: hidden;
}
.hTrack {
	float: left;
	height: 15px;
	width: 255px;
	position: relative;
	background: #ddd;
	overflow: hidden;
}
.vThumb, .hThumb {
	position: absolute;
	top: 0;
	left: 0;
	height: 15px;
	width: 15px;
	background: #aaa;
	overflow: hidden;
}
.arrowUp, .arrowDown, .arrowLeft, .arrowRight, .corner {
	height: 15px;
	width: 15px;
	background: #777;
	overflow: hidden;
}
.arrowLeft, .arrowRight, .corner {
	float: left;
}
.corner {
	background: #000;
}	

</style>

And this markup:

<div id="scrollmain">
		<div id="scrollcontent">
			<div class="text">

				<p>aLongUnbrokenStringOfTextToActivateTheHorizontalScrollbar....</p>
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
				
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>			
			</div>
		</div>	
	</div>
	
	<div class="notes">
	<strong>An Instance of the Scrollbar Class with Arrows and Horizontal Scrollbar Options Set to False</strong>
	</div> 
	
<div id="scrollmain2">
		<div id="scrollcontent2">
			<div class="text">
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
				
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>		
			</div>

		</div>	
	</div>




*/

	var ScrollBar = new Class({

		Implements: [Events, Options],

		options: {
			maxThumbSize: 15,
			wheel: 8,
			arrows: true,
			hScroll: true // horizontal scrollbars
		},

		initialize: function(main, content, options){
			this.setOptions(options);
			
			this.main = $(main);
			this.content = $(content);
			
			if (this.options.arrows == true){
				this.arrowOffset = 30;
			} else {
				this.arrowOffset = 0;
			}
			
			if (this.options.hScroll == true){
				this.hScrollOffset = 15;
			} else {
				this.hScrollOffset = 0;
			}				

			this.vScrollbar = new Element('div', {
    				'class': 'vScrollbar'
				}).injectAfter(this.content);				

			if (this.options.arrows == true){				
				this.arrowUp = new Element('div', {
    					'class': 'arrowUp'
					}).injectInside(this.vScrollbar);
			}	

			this.vTrack = new Element('div', {
    				'class': 'vTrack'
				}).injectInside(this.vScrollbar);
				
			this.vThumb = new Element('div', {
    				'class': 'vThumb'
				}).injectInside(this.vTrack);

			if (this.options.arrows == true){				
				this.arrowDown = new Element('div', {
    					'class': 'arrowDown'
					}).injectInside(this.vScrollbar);
			}		
			
			this.hScrollbar = new Element('div', {
    				'class': 'hScrollbar'
				}).injectAfter(this.vScrollbar);

			if (this.options.arrows == true){							
				this.arrowLeft = new Element('div', {
    					'class': 'arrowLeft'
					}).injectInside(this.hScrollbar);
			}		

			this.hTrack = new Element('div', {
    				'class': 'hTrack'
				}).injectInside(this.hScrollbar);
				
			this.hThumb = new Element('div', {
    				'class': 'hThumb'
				}).injectInside(this.hTrack);							
	
			if (this.options.arrows == true){
				this.arrowRight = new Element('div', {
    					'class': 'arrowRight'
					}).injectInside(this.hScrollbar);
			}											

			this.corner = new Element('div', {
    				'class': 'corner'
				}).injectAfter(this.hScrollbar);
			
			this.bound = {
				'vStart': this.vStart.bind(this),
				'hStart': this.hStart.bind(this),				
				'end': this.end.bind(this),
				'vDrag': this.vDrag.bind(this),
				'hDrag': this.hDrag.bind(this),				
				'wheel': this.wheel.bind(this),
				'vPage': this.vPage.bind(this),
				'hPage': this.hPage.bind(this)				
			};

			this.vPosition = {};
			this.hPosition = {};			
			this.vMouse = {};
			this.hMouse = {};			
			this.update();
			this.attach();
		},

		update: function(){
			
			this.main.setStyle('height', this.content.offsetHeight + this.hScrollOffset);
			this.vTrack.setStyle('height', this.content.offsetHeight - this.arrowOffset);
						
			this.main.setStyle('width', this.content.offsetWidth + 15);
			this.hTrack.setStyle('width', this.content.offsetWidth - this.arrowOffset);
			
			// Remove and replace vertical scrollbar			
			if (this.content.scrollHeight <= this.main.offsetHeight) {
				this.vScrollbar.setStyle('display', 'none');
				if (this.options.hScroll == true){				
					this.hTrack.setStyle('width', this.hTrack.offsetWidth + 15);
				}	
				this.content.setStyle('width', this.content.offsetWidth + 15);	
			} else {
				this.vScrollbar.setStyle('display', 'block');			
			}
			
			if (this.options.hScroll == true){			
			
				// Remove and replace horizontal scrollbar
				if (this.content.scrollWidth <= this.main.offsetWidth) {
					this.hScrollbar.setStyle('display', 'none');
					this.vTrack.setStyle('height', this.vTrack.offsetHeight + this.hScrollOffset);				
					this.content.setStyle('height', this.content.offsetHeight + this.hScrollOffset);	
				} else {
					this.hScrollbar.setStyle('display', 'block');			
				}
			
				// Remove and replace bottom right corner spacer			
				if (this.content.scrollHeight <= this.main.offsetHeight || this.content.scrollWidth <= this.main.offsetWidth) {
					this.corner.setStyle('display', 'none');				
				} else {
					this.corner.setStyle('display', 'block');			
				}		
			
				// Horizontal

				this.hContentSize = this.content.offsetWidth;
				this.hContentScrollSize = this.content.scrollWidth;
				this.hTrackSize = this.hTrack.offsetWidth;

				this.hContentRatio = this.hContentSize / this.hContentScrollSize;

				this.hThumbSize = (this.hTrackSize * this.hContentRatio).limit(this.options.maxThumbSize, this.hTrackSize);

				this.hScrollRatio = this.hContentScrollSize / this.hTrackSize;

				this.hThumb.setStyle('width', this.hThumbSize);

				this.hUpdateThumbFromContentScroll();
				this.hUpdateContentFromThumbPosition();			

			} else {
					this.hScrollbar.setStyle('display', 'none');
					this.corner.setStyle('display', 'none');										
			}
			

			// Vertical
			
			this.vContentSize = this.content.offsetHeight;
			this.vContentScrollSize = this.content.scrollHeight;
			this.vTrackSize = this.vTrack.offsetHeight;

			this.vContentRatio = this.vContentSize / this.vContentScrollSize;

			this.vThumbSize = (this.vTrackSize * this.vContentRatio).limit(this.options.maxThumbSize, this.vTrackSize);

			this.vScrollRatio = this.vContentScrollSize / this.vTrackSize;

			this.vThumb.setStyle('height', this.vThumbSize);

			this.vUpdateThumbFromContentScroll();
			this.vUpdateContentFromThumbPosition();
			
		},

		vUpdateContentFromThumbPosition: function(){
			this.content.scrollTop = this.vPosition.now * this.vScrollRatio;
		},
		
		hUpdateContentFromThumbPosition: function(){
			this.content.scrollLeft = this.hPosition.now * this.hScrollRatio;
		},		

		vUpdateThumbFromContentScroll: function(){
			this.vPosition.now = (this.content.scrollTop / this.vScrollRatio).limit(0, (this.vTrackSize - this.vThumbSize));
			this.vThumb.setStyle('top', this.vPosition.now);
		},
		
		hUpdateThumbFromContentScroll: function(){
			this.hPosition.now = (this.content.scrollLeft / this.hScrollRatio).limit(0, (this.hTrackSize - this.hThumbSize));
			this.hThumb.setStyle('left', this.hPosition.now);
		},		

		attach: function(){
			this.vThumb.addEvent('mousedown', this.bound.vStart);
			if (this.options.wheel) this.content.addEvent('mousewheel', this.bound.wheel);
			this.vTrack.addEvent('mouseup', this.bound.vPage);
			
			this.hThumb.addEvent('mousedown', this.bound.hStart);
			this.hTrack.addEvent('mouseup', this.bound.hPage);			
			
			if (this.options.arrows == true){
				this.arrowUp.addEvent('mousedown', function(event){
						this.interval = (function(event){
						this.content.scrollTop -= this.options.wheel;
						this.vUpdateThumbFromContentScroll();
					}.bind(this).periodical(40))
				}.bind(this));
			
				this.arrowUp.addEvent('mouseup', function(event){
					$clear(this.interval);
				}.bind(this));
			
				this.arrowUp.addEvent('mouseout', function(event){
					$clear(this.interval);
				}.bind(this));
						
				this.arrowDown.addEvent('mousedown', function(event){
						this.interval = (function(event){
						this.content.scrollTop += this.options.wheel;
						this.vUpdateThumbFromContentScroll();
					}.bind(this).periodical(40))
				}.bind(this));
			
				this.arrowDown.addEvent('mouseup', function(event){
					$clear(this.interval);
				}.bind(this));
			
				this.arrowDown.addEvent('mouseout', function(event){
					$clear(this.interval);
				}.bind(this));
			
				this.arrowLeft.addEvent('mousedown', function(event){
						this.interval = (function(event){
						this.content.scrollLeft -= this.options.wheel;
						this.hUpdateThumbFromContentScroll();
					}.bind(this).periodical(40))
				}.bind(this));
			
				this.arrowLeft.addEvent('mouseup', function(event){
					$clear(this.interval);
				}.bind(this));
			
				this.arrowLeft.addEvent('mouseout', function(event){
					$clear(this.interval);
				}.bind(this));
			
				this.arrowRight.addEvent('mousedown', function(event){
						this.interval = (function(event){
						this.content.scrollLeft += this.options.wheel;
						this.hUpdateThumbFromContentScroll();
					}.bind(this).periodical(40))
				}.bind(this));
			
				this.arrowRight.addEvent('mouseup', function(event){
					$clear(this.interval);
				}.bind(this));
			
				this.arrowRight.addEvent('mouseout', function(event){
					$clear(this.interval);
				}.bind(this));
			}			
						
		},
		
		wheel: function(event){
			this.content.scrollTop -= event.wheel * this.options.wheel;
			this.vUpdateThumbFromContentScroll();
			event.stop();
		},

		vPage: function(event){
			if (event.page.y > this.vThumb.getPosition().y) this.content.scrollTop += this.content.offsetHeight;
			else this.content.scrollTop -= this.content.offsetHeight;
			this.vUpdateThumbFromContentScroll();
			event.stop();
		},
		
		hPage: function(event){
			if (event.page.x > this.hThumb.getPosition().x) this.content.scrollLeft += this.content.offsetWidth;
			else this.content.scrollLeft -= this.content.offsetWidth;
			this.hUpdateThumbFromContentScroll();
			event.stop();
		},		

		vStart: function(event){
			this.vMouse.start = event.page.y;
			this.vPosition.start = this.vThumb.getStyle('top').toInt();
			document.addEvent('mousemove', this.bound.vDrag);
			document.addEvent('mouseup', this.bound.end);
			this.vThumb.addEvent('mouseup', this.bound.end);
			event.stop();
		},
		
		hStart: function(event){
			this.hMouse.start = event.page.x;		
			this.hPosition.start = this.hThumb.getStyle('left').toInt();
			document.addEvent('mousemove', this.bound.hDrag);
			document.addEvent('mouseup', this.bound.end);
			this.hThumb.addEvent('mouseup', this.bound.end);
			event.stop();
		},		

		end: function(event){
			document.removeEvent('mousemove', this.bound.vDrag);
			document.removeEvent('mousemove', this.bound.hDrag);			
			document.removeEvent('mouseup', this.bound.end);
			this.vThumb.removeEvent('mouseup', this.bound.end);
			this.hThumb.removeEvent('mouseup', this.bound.end);			
			event.stop();
		},

		vDrag: function(event){
			this.vMouse.now = event.page.y;
			this.vPosition.now = (this.vPosition.start + (this.vMouse.now - this.vMouse.start)).limit(0, (this.vTrackSize - this.vThumbSize));
			this.vUpdateContentFromThumbPosition();
			this.vUpdateThumbFromContentScroll();
			event.stop();
		},
		
		hDrag: function(event){
			this.hMouse.now = event.page.x;
			this.hPosition.now = (this.hPosition.start + (this.hMouse.now - this.hMouse.start)).limit(0, (this.hTrackSize - this.hThumbSize));
			this.hUpdateContentFromThumbPosition();
			this.hUpdateThumbFromContentScroll();
			event.stop();
		}		

	});