// scroller.js gives simple div-based scroll
// Bob Hanson 9:22 PM 7/21/2005
// VERY simple div-based scroller. 
// body needs onload=initScrollers()
//   then, somewhere: document.write(newScroller())
//   with optional parameters: newScroller(name,caption,fCallback,width,x,y,isvertical,magnitude,initialvalue,factor)

// fCallback must be string form of function, using _n, _v, _p (name, value, position) 
// For example, "newChart(Chart,'_n','_v','_p')

// to set a scroller value from code, use resetScroller()


Scrollers=new Array()
isScrollerInitialized=false

function initScrollers(){
 setTimeout('resetScroller("",-1)',100)
}

function resetScroller(which,value){
 for(var name in Scrollers){if(!which||name==which){
	Scrollers[name].isinitialized=false
	setScrollValue(name,0)
	setScrollValue(name,(value>=0?value:Scrollers[name].initialvalue),1)
	Scrollers[name].isinitialized=true
 }}
}

function setScrollPosition(name,pos){
 var d=0
 var S=Scrollers[name]
 d=document.getElementById("scr_"+name)
 if(S.isvertical){
	d.scrollTop=pos
 }else{
	d.scrollLeft=pos
 }
 S.pos=pos
 S.value=scrollValue(name)
 setScrollCaption(name)
}

function setScrollValue(name,value,dotrigger){
	var S=Scrollers[name]
	var pos=Math.floor(value/S.magnitude*S.width*S.factor)
	S.pos=pos
	S.value=scrollValue(name)
	setScrollPosition(name,pos)
//	if(dotrigger)checkScroll(name)
}

function scrollValue(name){
 var S=Scrollers[name]
 var value=S.pos/(S.width*S.factor)*S.magnitude
 if(S.magnitude>1)value=Math.floor(value)
 if(S.magnitude==1)value=Math.floor(value*100)/100
 return value
}

function checkScroll(name){
 var pos=0
 var value=0
 var S=new Array()
 var d=0
	S=Scrollers[name]
	d=document.getElementById("scr_"+name)
	pos=(S.isvertical?d.scrollTop:d.scrollLeft)
	if(pos!=S.pos){
		S.pos=pos //0 to 20*width
		S.value=value=scrollValue(name)
		setScrollCaption(name)
		if(S.isinitialized) {
//			alert("name: "+S.name+"\nposition: "+S.pos+"\nvalue: "+S.value+"\ncallback: "+S.callback)
			setTimeout(strScrollValues(S,S.callback),10)
		}
	}
}

function strScrollValues(S,what){
	return what.replace(/\_n/,S.name).replace(/\_p/,S.pos).replace(/\_v/,S.value)
}

function setScrollCaption(name){
	var caption=""
	var S=Scrollers[name]
	if(S.caption.indexOf("_")>=0){
		caption=strScrollValues(S,S.caption)
//document.title=name+" "+caption
		document.getElementById("scr_"+name+"_caption").innerHTML=caption
	}
}

function testScroll(name,value,position){
 document.title="this is function testScroll('"+name+"',"+value+","+position+")"
}

function newScroller(name,caption,fCallback,width,x,y,isvertical,magnitude,initialvalue,factor){
 if(!name)name="scroll-test"
 if(!caption)caption="testing: pos=_p value=_v"
 if(!fCallback)fCallback="testScroll('_n',_v,_p)"
 if(!width)width=300
 if(isNaN(x))x=100
 if(isNaN(y))y=100
 if(!isvertical)isvertical=0
 if(!magnitude)magnitude=100
 if(isNaN(initialvalue))initialvalue=magnitude/2
 if(!factor)factor=4
 var s=""
 var sout=""
 Scrollers[name]=new Array()
 var S=Scrollers[name]
 S.name=name
 S.caption=caption
 S.width=width
 S.x=x
 S.y=y
 S.isvertical=isvertical
 S.magnitude=magnitude
 S.callback=fCallback
 S.value=initialvalue
 S.factor=factor
 S.initialvalue=initialvalue

 if(isvertical){
//	sout="\n<div id=scr_"+name+"_outer style=\" position:absolute;left:"+(x-20)+";top:"+y+";width:1000;height:"+width+"\">"
//	+"\n<div id=scr_"+name+" onscroll=\"checkScroll('"+name+"')\" style=\" width:30;height:"+width+";overflow:auto\">"
//	+"\n<img src=transp.gif width=1 height="+(width*(factor+1))+">"
//	+"\n</div><span id=scr_"+name+"_caption>"+caption+"</span></div>"
	sout="\n<div id=scr_"+name+"_outer style=\" height:"+width+"\">"
	+"\n<div id=scr_"+name+" onscroll=\"checkScroll('"+name+"')\" style=\" width:30;height:"+width+";overflow:auto\">"
	+"\n<img src=transp.gif width=1 height="+(width*(factor+1))+">"
	+"\n</div><span id=scr_"+name+"_caption>"+caption+"</span></div>"
 }else{
//	sout="\n<div id=scr_"+name+"_outer style=\" position:absolute;left:"+x+";top:"+(y-40)+";height:10;width:"+width+"\">"
//	+"\n<div id=scr_"+name+" onscroll=\"checkScroll('"+name+"')\" style=\"height:30;width:"+width+";overflow:auto\">"
//	+"<img src=transp.gif height=1 width="+(width*(factor+1))+">"
//	+"</div><span id=scr_"+name+"_caption>"+caption+"</span></div>"
	sout="\n<div id=scr_"+name+"_outer style=\" width:"+width+"\">"
	+"\n<div id=scr_"+name+" onscroll=\"checkScroll('"+name+"')\" style=\"height:30;width:"+width+";overflow:auto\">"
	+"<img src=transp.gif height=1 width="+(width*(factor+1))+">"
	+"</div><span id=scr_"+name+"_caption>"+caption+"</span></div>"
 }
 S.div=sout
 return sout
}