/* www.gibney.org entry nr. 49: savescroll */

/*

Savescroll by Gibney Enterprises

This saves the position the document is currently scrolled to in a cookie
if you visit the document again it restores the poition
Currently only one value per domain is saved

*/

function getCookieValue(cookieName)
{
	var value=null;
	if(document.cookie != "") 
	{
		cookieName=cookieName+"=";
		
		var start=document.cookie.indexOf(cookieName);
		if(start>=0) 
		{
			start=start+cookieName.length;
			
			var end=document.cookie.indexOf(";", start);
			if(end<0) end=document.cookie.length;
			
			value=document.cookie.substring(start,end);
			value=unescape(value);
		}
	}
	return value;
}

function setCookie(cookieName,cookieValue, expires, path, domain, secure)
{
	var cookie=cookieName+"="+escape(cookieValue)+";";
	if (expires) cookie+=" expires="+expires+";";
	if (path)    cookie+=" path="+path+";";
	if (domain)  cookie+=" domain="+domain+";";
	if (secure)  cookie+=" secure;";
	document.cookie=cookie;
}

function getPage()
{
	if ("undefined"!=typeof(mg_savescroll_forced_page)) return mg_savescroll_forced_page;
	
	var name=window.location.pathname;
	// var indexpos=name.indexOf('index.php');
	// if (indexpos==name.length-9) name=name.substring(0,name.length-9);
	
	if (name.substring(name.length-9)=='index.php') name=name.substring(0,name.length-9);
	
	name=escape(name);
	
	return name;
}

function saveScrollPos()
{
	var page=getPage();
	
	var scrollPos=0;
	
	if(document.pageYOffset) scrollPos=document.pageYOffset;
	else                     scrollPos=document.body.scrollTop;
	
	setCookie('mg_savescroll',page+'|'+scrollPos,false,'/');
}

function restoreScrollPos()
{
	var page=getPage();
	var scrollPos=null;
	
	// is there a cookie?
	var cookie=getCookieValue('mg_savescroll');
	if (cookie==null) return;
	
	// is it for this page?
	var pos=cookie.indexOf(page);
	if (pos!=0) return;
	
	// get the saved position
	var pos=cookie.indexOf("|");
	if (pos>0) scrollPos=cookie.substr(pos+1);
	
	// if we have a saved position scroll there...
	if (scrollPos!=null) window.scrollTo(0, scrollPos);
}

document.onmousedown=saveScrollPos;
window.onload=restoreScrollPos;