ÿþ//Animated Collapsible DIV- Author: Dynamic Drive (http://www.dynamicdrive.com)

//Last updated Aug 1st, 07'. Fixed bug with "block" parameter not working when persist is enabled

//Updated June 27th, 07'. Added ability for a DIV to be initially expanded.



var uniquepageid=window.location.href.replace("http://"+window.location.hostname, "").replace(/^\//, "") //get current page path and name, used to uniquely identify this page for persistence feature



function animatedcollapse(divId, animatetime, persistexpand, initstate){

	this.divId=divId

	this.divObj=document.getElementById(divId)

	this.divObj.style.overflow="hidden"

	this.timelength=animatetime

	this.initstate=(typeof initstate!="undefined" && initstate=="block")? "block" : "contract"

	this.isExpanded=animatedcollapse.getCookie(uniquepageid+"-"+divId) //"yes" or "no", based on cookie value

	this.contentheight=parseInt(this.divObj.style.height)

	var thisobj=this

	if (isNaN(this.contentheight)){ //if no CSS "height" attribute explicitly defined, get DIV's height on window.load

		animatedcollapse.dotask(window, function(){thisobj._getheight(persistexpand)}, "load")

		if (!persistexpand && this.initstate=="contract" || persistexpand && this.isExpanded!="yes" && this.isExpanded!="") //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)

			this.divObj.style.visibility="hidden" //hide content (versus collapse) until we can get its height

	}

	else if (!persistexpand && this.initstate=="contract" || persistexpand && this.isExpanded!="yes" && this.isExpanded!="") //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)

		this.divObj.style.height=0 //just collapse content if CSS "height" attribute available

	if (persistexpand)

		animatedcollapse.dotask(window, function(){animatedcollapse.setCookie(uniquepageid+"-"+thisobj.divId, thisobj.isExpanded)}, "unload")

}



animatedcollapse.prototype._getheight=function(persistexpand){

	this.contentheight=this.divObj.offsetHeight

	if (!persistexpand && this.initstate=="contract" || persistexpand && this.isExpanded!="yes"){ //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)

		this.divObj.style.height=0 //collapse content

		this.divObj.style.visibility="visible"

	}

	else //else if persistence is enabled AND this content should be expanded, define its CSS height value so slideup() has something to work with

		this.divObj.style.height=this.contentheight+"px"

}





animatedcollapse.prototype._slideengine=function(direction){

	var elapsed=new Date().getTime()-this.startTime //get time animation has run

	var thisobj=this

	if (elapsed<this.timelength){ //if time run is less than specified length

		var distancepercent=(direction=="down")? animatedcollapse.curveincrement(elapsed/this.timelength) : 1-animatedcollapse.curveincrement(elapsed/this.timelength)

	this.divObj.style.height=distancepercent * this.contentheight +"px"

	this.runtimer=setTimeout(function(){thisobj._slideengine(direction)}, 10)

	}

	else{ //if animation finished

		this.divObj.style.height=(direction=="down")? this.contentheight+"px" : 0

		this.isExpanded=(direction=="down")? "yes" : "no" //remember whether content is expanded or not

		this.runtimer=null

	}

}





animatedcollapse.prototype.slidedown=function(){

	if (typeof this.runtimer=="undefined" || this.runtimer==null){ //if animation isn't already running or has stopped running

		if (isNaN(this.contentheight)) //if content height not available yet (until window.onload)

			alert("Please wait until document has fully loaded then click again")

		else if (parseInt(this.divObj.style.height)==0){ //if content is collapsed

			this.startTime=new Date().getTime() //Set animation start time

			this._slideengine("down")

		}

	}

}



animatedcollapse.prototype.slideup=function(){

	if (typeof this.runtimer=="undefined" || this.runtimer==null){ //if animation isn't already running or has stopped running

		if (isNaN(this.contentheight)) //if content height not available yet (until window.onload)

			alert("Please wait until document has fully loaded then click again")

		else if (parseInt(this.divObj.style.height)==this.contentheight){ //if content is expanded

			this.startTime=new Date().getTime()

			this._slideengine("up")

		}

	}

}



animatedcollapse.prototype.slideit=function(){

	if (isNaN(this.contentheight)) //if content height not available yet (until window.onload)

		alert("Please wait until document has fully loaded then click again")

	else if (parseInt(this.divObj.style.height)==0)

		this.slidedown()

	else if (parseInt(this.divObj.style.height)==this.contentheight)

		this.slideup()

}



// -------------------------------------------------------------------

// A few utility functions below:

// -------------------------------------------------------------------



animatedcollapse.curveincrement=function(percent){

	return (1-Math.cos(percent*Math.PI)) / 2 //return cos curve based value from a percentage input

}





animatedcollapse.dotask=function(target, functionref, tasktype){ //assign a function to execute to an event handler (ie: onunload)

	var tasktype=(window.addEventListener)? tasktype : "on"+tasktype

	if (target.addEventListener)

		target.addEventListener(tasktype, functionref, false)

	else if (target.attachEvent)

		target.attachEvent(tasktype, functionref)

}



animatedcollapse.getCookie=function(Name){ 

	var re=new RegExp(Name+"=[^;]+", "i"); //construct RE to search for target name/value pair

	if (document.cookie.match(re)) //if cookie found

		return document.cookie.match(re)[0].split("=")[1] //return its value

	return ""

}



animatedcollapse.setCookie=function(name, value){

		document.cookie = name+"="+value

}