// vertical-scroll.js by rod.rant-on.net | rodmorelos@msn.com
// keep these two lines and you're free to use this code

// object constructor
function createObjectById(id)
{
	this.el = document.getElementById ? document.getElementById(id) : null;
	if (!this.el) 
		throw new Error('Element with "' + id + '" id not found.');
	this.css = this.el.style;
	this.i = createObjectById.registry.length;
	createObjectById.registry[this.i] = this;
	this.w = this.el.offsetWidth ? this.el.offsetWidth : 0;
	this.h = this.el.offsetHeight ? this.el.offsetHeight : 0;
	this.x = this.el.offsetLeft ? this.el.offsetLeft : 0;
	this.y = this.el.offsetTop ? this.el.offsetTop : 0;
	this.o = 100;
}
// global reference to the dhtml object
createObjectById.registry = [];

// update object values
createObjectById.prototype.update = function()
{
	this.w = this.el.offsetWidth ? this.el.offsetWidth : 0;
	this.h = this.el.offsetHeight ? this.el.offsetHeight : 0;
	this.x = this.el.offsetLeft ? this.el.offsetLeft : 0;
	this.y = this.el.offsetTop ? this.el.offsetTop : 0;
}
// visibility
createObjectById.prototype.show = function() { this.css.visibility = 'visible'; }
createObjectById.prototype.hide = function() { this.css.visibility = 'hidden'; }

// display
createObjectById.prototype.display = function(d) { this.css.display = d; }

// colors
createObjectById.prototype.fg = function(f) { this.css.color = f; }
createObjectById.prototype.bg = function(b) { this.css.backgroundColor = b; }

// set layer opacity (in percent, between 0 and 100)
createObjectById.prototype.setOpacity = function(o)
{
	if (typeof this.css.MozOpacity != 'undefined') { this.css.MozOpacity = (o / 100); this.o = o; }
	else if (this.el.filters) { this.css.filter = 'alpha(opacity=' + o + ')'; this.o = o; }
}
// moves a layer to (x, y) pixels
createObjectById.prototype.moveTo = function(x, y)
{
	if (x != null && typeof x == 'number')
	{
		x = Math.round(x);
		this.x = x;
		this.css.left = x + 'px';
	}
	if (y != null && typeof y == 'number')
	{
		y = Math.round(y);
		this.y = y;
		this.css.top = y + 'px';
	}
}
// resize layer to (width, height) pixels
createObjectById.prototype.setSize = function(w, h)
{
	if (w != null && typeof w == 'number')
	{
		if (w < 0) w = 0;
		w = Math.round(w);
		this.css.width = w + 'px';
	}
	if (h != null && typeof h == 'number')
	{
		if (h < 0) h = 0;
		h = Math.round(h);
		this.css.height = h + 'px';
	}
	this.update();
}
// clips layer to specific dimensions; (top, right, bottom, left) in pixels
createObjectById.prototype.clipTo = function(t, r, b, l)
{
	if (t < 0) t = 0; if (r < 0) r = 0; if (b < 0) b = 0; if (l < 0) l = 0;
	this.css.clip = 'rect(' + t + 'px, ' + r + 'px, ' + b + 'px, ' + l + 'px)';
}
// write content to layer
createObjectById.prototype.write = function(text)
{
	if (typeof this.el.innerHTML != 'undefined')
	{
		this.el.innerHTML = text;
		this.update();
	}
}
/******************** functions rodmorelos@msn.com find useful or are used in his scripts ******************/

// measure page width and height (the viewable canvas area)
function getViewport()
{
	if (document.documentElement && document.documentElement.scrollLeft) this.scrollX = document.documentElement.scrollLeft;
	else if (document.body && document.body.scrollLeft) this.scrollX = document.body.scrollLeft;
	else if (window.scrollX) this.scrollX = window.scrollX;
	else if (window.pageXOffset) this.scrollX = window.pageXOffset;
	else this.scrollX = 0;
	if (document.documentElement && document.documentElement.scrollTop) this.scrollY = document.documentElement.scrollTop;
	else if (document.body && document.body.scrollTop) this.scrollY = document.body.scrollTop;
	else if (window.scrollY) this.scrollY = window.scrollY;
	else if (window.pageYOffset) this.scrollY = window.pageYOffset;
	else this.scrollY = 0;
	if (document.documentElement && document.documentElement.clientWidth) this.width = document.documentElement.clientWidth;
	else if (document.body && document.body.clientWidth) this.width = document.body.clientWidth;
	else if (window.innerWidth) this.width = window.innerWidth;
	else this.width = 0;
	if (document.documentElement && document.documentElement.clientHeight) this.height = document.documentElement.clientHeight;
	else if (document.body && document.body.clientHeight) this.height = document.body.clientHeight;
	else if (window.innerHeight) this.height = window.innerHeight;
	else this.height = 0;
}

// event listeners
// object       = the object to attach the event handler to
// eventType    = the type of event to listen for
// functionName = the handler function to execute when the event is fired
// capture      = use event capture?
function addEvent(object, eventType, functionName, capture)
{
	if (object.addEventListener)
	{
		object.addEventListener(eventType, functionName, capture);
		return true;
	}
	else if (object.attachEvent)
	{
		var ae = object.attachEvent('on' + eventType, functionName);
		return ae;
	}
	else
	{
		object['on' + eventType] = functionName; 
	}
}

function removeEvent(object, eventType, functionName, capture)
{
	if (object.removeEventListener)
	{
		object.removeEventListener(eventType, functionName, capture);
		return true;
	}
	else if (object.detachEvent)
	{
		var re = object.detachEvent('on' + eventType, functionName);
		return re;
	}
	else { object['on' + eventType] = null; }
}

function fixEvent(e, currentTarget)
{
	if (!e) e = event;
	if (!e.target) e.target = e.srcElement;
	if (!e.currentTarget) e.currentTarget = currentTarget;
	if (typeof e.layerX == 'undefined') e.layerX = e.offsetX;
	if (typeof e.layerY == 'undefined') e.layerY = e.offsetY;
	if (typeof e.clientX == 'undefined') e.clientX = e.pageX;
	if (typeof e.clientY == 'undefined') e.clientY = e.pageY;
	if (!e.stopPropagation) e.stopPropagation = function() { this.cancelBubble = true; }
	if (!e.preventDefault) 
		e.preventDefault = function() 
		{ 
			this.returnValue = false; 
		}
	return e;
}
// browser check
function browserCheck()
{
	this.ua = navigator.userAgent.toLowerCase();
	this.dom = document.getElementById ? 1 : 0;
	this.op7 = (this.dom && this.ua.indexOf('opera 7') > -1 || this.ua.indexOf('opera/7') > -1) ? 1 : 0;
	this.ie  = this.ua.indexOf("msie") != -1;
	this.ie5 = (this.dom && this.ua.indexOf('msie 5') > -1) ? 1 : 0;
	this.ie6 = (this.dom && this.ua.indexOf('msie 6') > -1) ? 1 : 0;
	this.moz = (this.dom && this.ua.indexOf('mozilla') > -1 && this.ua.indexOf('gecko') > -1) ? 1 : 0;
	this.mac = this.ua.indexOf("mac") != -1;
	return this;
}
// returns a random number between x and y (integers)
function rand(x, y) 
{ 
	return (Math.round(Math.random() * (y - x)) + x); 
}
// browser check variable
var bw = browserCheck();

/************************** vertical-scroller by rod.rant-on.net | rodmorelos@msn.com **********************/

var scroller = 
{
	scrollables: 1, // set the number of scrollable scrollContent
	step: 30, 			// set the timeout between each scroll
	speed: 15, 			// set the scroll speed
	wheelSpeed: 15, // set the scroll speed when using the mouse wheel
	wheelScrolled: false,
	timer: 0,
	contentY: 0,
	dragY: 0,
	clickY: 0,

	mouseDown: function(e)
	{
		e = fixEvent(e);
		var canvas = new getViewport();
		var mouseY = e.clientY + canvas.scrollY;
		var target = (e.target.nodeType == 3 || e.target.tagName.toLowerCase() == 'img') ? e.target.parentNode : e.target;
		scroller.wheelScrolled = false;
		for (var i = 1; i <= scroller.scrollables; i++)
		{
			if (target.id == scroller.bar[i].el.id)
			{
				//the function e.preventDefault() prevents sitecontent from being marked when cursor is moved away from the scrollbar. But ie on mac does not understand e.preventDefault(). The scrollbar cannot be used on ie for mac but is visible as an indicator.
				if(!(bw.mac && bw.ie))
				{
					scroller.bar[i].grab = true;
					scroller.clickY = mouseY - scroller.bar[i].y;
					e.preventDefault();
				}
			}
			else if (target.id == scroller.track[i].el.id)
			{
				if (scroller.content[i].h > scroller.container[i].h)
				{
					scroller.track[i].grab = true;
					scroller.dragY = e.layerY - (scroller.bar[i].h / 2);
					if (scroller.dragY < 0) 
						scroller.dragY = 0;
					if (scroller.dragY > scroller.track[i].h - scroller.bar[i].h) 
						scroller.dragY = scroller.track[i].h - scroller.bar[i].h;
					scroller.contentY = 0 - (scroller.dragY * (scroller.content[i].h - scroller.container[i].h) / Math.round(scroller.track[i].h - scroller.bar[i].h));
					scroller.content[i].moveTo(0, scroller.contentY);
					scroller.bar[i].moveTo(0, scroller.dragY);
					if(!(bw.mac && bw.ie)) e.preventDefault(e);
				}
			}
			else if (target.id == scroller.up[i].el.id)
			{
				scroller.up[i].grab = true;
				scroller.scroll(i, scroller.speed);
				if(!(bw.mac && bw.ie)) e.preventDefault();
			}
			else if (target.id == scroller.down[i].el.id)
			{
				scroller.down[i].grab = true;
				scroller.scroll(i, -scroller.speed);
				if(!(bw.mac && bw.ie)) e.preventDefault();
			}
		}
	},

	mouseUp: function(e)
	{
		for (var i = 1; i <= scroller.scrollables; i++)
		{
			scroller.bar[i].grab = false;
			scroller.track[i].grab = false;
			scroller.up[i].grab = false;
			scroller.down[i].grab = false;
		}
		clearTimeout(scroller.timer);
	},

	mouseMove: function(e)
	{
		for (var i = 1; i <= scroller.scrollables; i++)
		{
			if (scroller.bar[i].grab && scroller.content[i].h > scroller.container[i].h)
			{
				e = fixEvent(e);
				var canvas = new getViewport();
				var mouseY = e.clientY + canvas.scrollY;
				scroller.dragY = mouseY - scroller.clickY;
				if (scroller.dragY < 0) 
					scroller.dragY = 0;
				if (scroller.dragY > scroller.track[i].h - scroller.bar[i].h) 
					scroller.dragY = scroller.track[i].h - scroller.bar[i].h;
				scroller.contentY = 0 - (scroller.dragY * (scroller.content[i].h - scroller.container[i].h) / Math.round(scroller.track[i].h - scroller.bar[i].h));
				scroller.content[i].moveTo(0, scroller.contentY);
				scroller.bar[i].moveTo(0, scroller.dragY);
				if(!(bw.mac && bw.ie)) e.preventDefault();
			}
		}
	},

	scroll: function(num, speed)
	{
		if (scroller.content[num].y < 0 || scroller.content[num].y > -scroller.content[num].h + scroller.container[num].h)
		{
			scroller.contentY = scroller.content[num].y + speed;
			if (scroller.contentY < -(scroller.content[num].h - scroller.container[num].h)) scroller.contentY = -scroller.content[num].h + scroller.container[num].h;
			else if (scroller.contentY > 0) scroller.contentY = 0;
			scroller.content[num].moveTo(0, scroller.contentY);
			scroller.dragY = 0 - (scroller.content[num].y * Math.round(scroller.track[num].h - scroller.bar[num].h) / (scroller.content[num].h - scroller.container[num].h));
			scroller.bar[num].moveTo(0, scroller.dragY);
			if (!scroller.wheelScrolled) scroller.timer = setTimeout('scroller.scroll(' + num + ', ' + speed + ')', scroller.step);
		}
	},

	wheelScroll: function(e)
	{
		e = fixEvent(e);
		var el = e.target;
		if (el.id.slice(0, el.id.length - 1) != 'scrollContent')
		{
			do el = el.parentNode;
			while (el.tagName.toLowerCase() != 'div' || el.id.slice(0, el.id.length - 1) != 'scrollContent')
		}
		var i = el.id.charAt(el.id.length - 1);
		if (window.event.wheelDelta <= -120)
		{
			scroller.wheelScrolled = true;
			scroller.scroll(i, -scroller.wheelSpeed);
		}
		else if (window.event.wheelDelta >= 120)
		{
			scroller.wheelScrolled = true;
			scroller.scroll(i, scroller.wheelSpeed);
		}
		if(!(bw.mac && bw.ie)) e.preventDefault();
	},
	
	/**********************************************************************************************************/
	/*
	/* This function is developed by Morten Prom (www.mortenprom.com) @ Moje Art Drector AS (www.mad-design.no)
	/* Keep these two lines and you're free to use this code.
	/* The setHeight() function can be used to change the height of a scroller-object.
	/*     id              : Scroller number
	/*     containerHeight : New height of container
	/*     trackHeight     : New height of track
	/*
	/**********************************************************************************************************/
	
	setHeight: function(id, containerHeight, trackHeight)
	{
		var containerHeightBeforeReposition = this.container[id].h;
		this.container[id].h = containerHeight;
		this.track[id].h = trackHeight;
		var hiddenContent = this.content[id].h - this.container[id].h;
		var hiddenTopContentPercent = (-this.contentY) / hiddenContent;
		
		var visibleScrollTrack = this.track[id].h - this.bar[id].h;
		
		var visibleContentHeight = this.contentY + this.content[id].h;
		if(visibleContentHeight < this.container[id].h)
		{
			this.contentY = this.contentY + (this.container[id].h - visibleContentHeight);
			this.content[id].moveTo(0, this.contentY);
			this.dragY = visibleScrollTrack;
			this.bar[id].moveTo(0, this.dragY);
		}
		else
		{
			this.dragY = visibleScrollTrack * hiddenTopContentPercent;
			this.bar[id].moveTo(0, this.dragY);
		}
	},
	
	/**********************************************************************************************************/
	/*
	/* This function is developed by Morten Prom (www.mortenprom.com) @ Moje Art Drector AS (www.mad-design.no)
	/* Keep these two lines and you're free to use this code.
	/* The updateContent() function can be used to update the content of the scroller object when the content
	/* is changed.
	/*
	/**********************************************************************************************************/
	
	updateContent: function(id)
	{
		this.content[id].update();
	},

	init: function()
	{
		scroller.container = new Array();
		scroller.content = new Array();
		scroller.bar = new Array();
		scroller.up = new Array();
		scroller.down = new Array();
		scroller.track = new Array();
		for (var i = 1; i <= scroller.scrollables; i++)
		{
			scroller.container[i] = new createObjectById('scrollContainer' + i);
			scroller.content[i] = new createObjectById('scrollContent' + i);
			scroller.bar[i] = new createObjectById('scrollBar' + i);
			scroller.bar[i].grab = false;
			scroller.track[i] = new createObjectById('scrollTrack' + i);
			scroller.track[i].grab = false;
			scroller.up[i] = new createObjectById('scrollUp' + i);
			scroller.up[i].grab = false;
			scroller.down[i] = new createObjectById('scrollDown' + i);
			scroller.down[i].grab = false;
			if (bw.ie6) addEvent(scroller.content[i].el, 'mousewheel', scroller.wheelScroll, false);
		}
		addEvent(document, 'mousemove', scroller.mouseMove, false);
		addEvent(document, 'mousedown', scroller.mouseDown, false);
		addEvent(document, 'mouseup', scroller.mouseUp, false);
		//enkodeNormalDFO();
		//repositionObjects();
	}
}
//onload = scroller.init;