/* Tiny Scrolling - a smooth navigation between internal links and their destinations

by Marco Rosella - http://www.centralscrutinizer.it/en/design/js-php/tiny-scrolling

based on the works by Travis Beckham and Brian McAllister.

                v0.3 - March 27, 2006

Modifiche Alessio Argiolas 2009

*/



window.onload = function() {
	
	tinyScrolling.init();

	if(location.href.indexOf("#")==-1) location.href="#m";


	}



var tinyScrolling = {

	fast : 0,		 //valori maggiori di zero per la velocità dello scroll automatico, zero per usare il mouse

	speed : 15,      //set here the scroll speed: when this value increase, the speed decrease. 

	maxStep: 150,	 //set here the "uniform motion" step for long distances

	brakeK: 3,		 //set here the coefficient of slowing down

	defp : 50,		 

	IE : false,

	diffY : 0,

	patternY : 0,

	lastBackScroll : 0,

	lastMouseYpos : 0,

	lastMouseYstop : false,

	hash:null,		

	pause: false,

	currentBlock:null,

	requestedY:0,

	init: function() {

			var lnks = document.getElementsByTagName('a');   

			for(var i = 0, lnk; lnk = lnks[i]; i++) {   

				if ((lnk.href && lnk.href.indexOf('#') != -1) &&  ( (lnk.pathname == location.pathname) ||

				('/'+lnk.pathname == location.pathname) ) && (lnk.search == location.search)) {  

				lnk.onclick = tinyScrolling.initScroll;   		

				}   

			}

			setTimeout(tinyScrolling.backScroll,tinyScrolling.fast);		

			tinyScrolling.IE = document.all ? true:false;

			if (!tinyScrolling.IE) document.captureEvents(Event.MOUSEMOVE);

			document.onmousemove = tinyScrolling.getMouseXY;

	},

	getElementYpos: function(el){

			var y = 0;

			while(el.offsetParent){  

				y += el.offsetTop    

				el = el.offsetParent;

			}	return y;

	},		

	getScrollTop: function(){

			if(document.all) return (document.documentElement.scrollTop) ? document.documentElement.scrollTop : document.body.scrollTop;

			else return window.pageYOffset;   

	},	

	getWindowHeight: function(){

			if (window.innerHeight)	return window.innerHeight;

			if(document.documentElement && document.documentElement.clientHeight) return document.documentElement.clientHeight;

	},

	getDocumentHeight: function(){

			if (document.height) return document.height;

			if (document.body.offsetHeight) return document.body.offsetHeight;

	},

	initScroll: function(e){

			var targ;  

			tinyScrolling.pause = true;

			tinyScrolling.lastMouseYstop = true;

			tinyScrolling.lastBackScroll = tinyScrolling.patternY;

			document.body.style.backgroundImage="url('art/menumex.gif')";

			if (!e) var e = window.event;

			if (e.target) targ = e.target;

			else if (e.srcElement) targ = e.srcElement;   

			tinyScrolling.hash = targ.href.substr(targ.href.indexOf('#')+1,targ.href.length); 

			tinyScrolling.currentBlock = document.getElementById(tinyScrolling.hash);   

			if(!tinyScrolling.currentBlock) return;

			tinyScrolling.requestedY = tinyScrolling.getElementYpos(tinyScrolling.currentBlock); 

			tinyScrolling.scroll();  

			return false;

	},

	scroll: function(){

			var top  = tinyScrolling.getScrollTop();
			if(tinyScrolling.requestedY > top) {  

				var endDistance = Math.round((tinyScrolling.getDocumentHeight() - (top + tinyScrolling.getWindowHeight())) / tinyScrolling.brakeK);

				endDistance = Math.min(Math.round((tinyScrolling.requestedY-top)/ tinyScrolling.brakeK), endDistance);

				var offset = Math.max(2, Math.min(endDistance, tinyScrolling.maxStep));

			} else { var offset = - Math.min(Math.abs(Math.round((tinyScrolling.requestedY-top)/ tinyScrolling.brakeK)), tinyScrolling.maxStep);

			} window.scrollTo(0, top + offset);  

			if(Math.abs(top-tinyScrolling.requestedY) <= 1 || tinyScrolling.getScrollTop() == top) {

				window.scrollTo(0, tinyScrolling.requestedY);

				if(!document.all || window.opera) location.hash = tinyScrolling.hash;

				tinyScrolling.hash = null;

				document.body.style.backgroundImage="url('art/"+lang+"/menumex.png')";

				//document.getElementsByTagName("html")[0].style.backgroundPosition = "center "+(tinyScrolling.lastBackScroll)+"px";

				tinyScrolling.pause = false;

				setTimeout(tinyScrolling.backScroll,tinyScrolling.fast);

			} else 	setTimeout(tinyScrolling.scroll,tinyScrolling.speed);

	},

	backScroll: function(){			

		if (!tinyScrolling.pause && tinyScrolling.fast)

		{

			//document.getElementsByTagName("html")[0].style.backgroundPosition = "center "+(tinyScrolling.defp++)+"px";	

			if (tinyScrolling.defp == 155) tinyScrolling.defp = 0;

			setTimeout(tinyScrolling.backScroll,tinyScrolling.fast);

		}	

	},

	getMouseXY: function(ef){

			var tempY = 0;

			var windH = 0;

			if (!tinyScrolling.pause && !tinyScrolling.fast)

			{

				if (tinyScrolling.IE) { // grab the x-y pos.s if browser is IE

				tempY = event.clientY + document.body.scrollTop;

				windH = window.screen.availHeight;

				}

				else { // grab the x-y pos.s if browser is NS

				tempY = ef.pageY - window.scrollY;

				windH = window.innerHeight;

				}  

				if (tempY < 0) { tempY = 0; }

				tinyScrolling.lastMouseYpos = tempY;

				tempY = 155 - Math.floor( tempY / windH * 155);

				if (tinyScrolling.lastMouseYstop) 

				{

					tinyScrolling.diffY = tempY - tinyScrolling.lastBackScroll;

					tinyScrolling.lastMouseYstop = false;

				}				

				tempY -= tinyScrolling.diffY;

				if (tempY < 0) tempY += 155;

				if (tempY > 154) tempY -= 155;	

					

				tinyScrolling.patternY = tempY;

				//document.getElementsByTagName("html")[0].style.backgroundPosition = "center "+tempY+"px";

			}
			
			return true;

	}

}