// Javascript News Crawler

function pausescroller (content, divID, divClass, delay)
{
	this.content = content;					//message array content
	this.tickerid = divID;					//ID of ticker div to display information
	this.delay = delay;						//Delay between msg change, in miliseconds.
	this.mouseoverBol = 0; 					//Boolean to indicate whether mouse is currently over scroller (and pause it if it is)
	this.hiddendivpointer = 1; 				//index of message array for hidden div
	
	document.write('<div id="' + divID + '" class="' + divClass + '" style="position: relative; overflow: hidden">' + 
				   		'<div class="innerDiv" style="position: absolute; width: 100%" id="' + divID + '1">' + 
							content[0] + 
						'</div>' + 
						'<div class="innerDiv" style="position: absolute; width: 100%; visibility: hidden" id="' + divID + '2">' + 
							content[1] + 
						'</div>' + 
					'</div>');
	
	var scrollerinstance = this;
	if (window.addEventListener)			//run onload in DOM2 browsers
		window.addEventListener("load", function(){scrollerinstance.initialize()}, false);
	else
		if (window.attachEvent)				//run onload in IE5.5+
			window.attachEvent("onload", function(){scrollerinstance.initialize()});
		else 
			if (document.getElementById)	//if legacy DOM browsers, just start scroller after 0.5 sec
				setTimeout(function(){scrollerinstance.initialize()}, 500);
}

// -------------------------------------------------------------------
// initialize()- Initialize scroller method.
// -Get div objects, set initial positions, start up down animation
// -------------------------------------------------------------------

pausescroller.prototype.initialize = function()
{
	this.tickerdiv = document.getElementById(this.tickerid);
	this.visiblediv = document.getElementById(this.tickerid + "1");
	this.hiddendiv = document.getElementById(this.tickerid + "2");
	this.visibledivtop = parseInt(pausescroller.getCSSpadding(this.tickerdiv));
	
	//set width of inner DIVs to outer DIV's width minus padding (padding assumed to be top padding x 2)
	this.visiblediv.style.width = this.hiddendiv.style.width = this.tickerdiv.offsetWidth - (this.visibledivtop * 2) + "px";
	this.getinline(this.visiblediv, this.hiddendiv);
	this.hiddendiv.style.visibility = "visible";
	var scrollerinstance = this;
	document.getElementById(this.tickerid).onmouseover = function(){scrollerinstance.mouseoverBol = 1};
	document.getElementById(this.tickerid).onmouseout = function(){scrollerinstance.mouseoverBol = 0};
	if (window.attachEvent)					//Clean up loose references in IE
		window.attachEvent("onunload", function(){scrollerinstance.tickerdiv.onmouseover=scrollerinstance.tickerdiv.onmouseout=null});
	
	setTimeout(function(){scrollerinstance.animateup()}, this.delay);
}

// -------------------------------------------------------------------
// animateup()- Move the two inner divs of the scroller up and in sync
// -------------------------------------------------------------------

pausescroller.prototype.animateup = function()
{
	var scrollerinstance = this;
	if (parseInt(this.hiddendiv.style.top)>(this.visibledivtop+5))
	{
		this.visiblediv.style.top = parseInt(this.visiblediv.style.top) - 5 + "px";
		this.hiddendiv.style.top=parseInt(this.hiddendiv.style.top) - 5 + "px";
		setTimeout(function(){ scrollerinstance.animateup() }, 10);
	}
	else
	{
		this.getinline(this.hiddendiv, this.visiblediv);
		this.swapdivs();
		setTimeout(function(){ scrollerinstance.setmessage() }, this.delay);
	}
}

// -------------------------------------------------------------------
// swapdivs()- Swap between which is the visible and which is the hidden div
// -------------------------------------------------------------------

pausescroller.prototype.swapdivs = function()
{
	var tempcontainer = this.visiblediv;
	this.visiblediv = this.hiddendiv;
	this.hiddendiv = tempcontainer;
}

pausescroller.prototype.getinline = function(div1, div2)
{
	div1.style.top = this.visibledivtop + "px";
	div2.style.top = Math.max(div1.parentNode.offsetHeight, div1.offsetHeight) + "px";
}

// -------------------------------------------------------------------
// setmessage()- Populate the hidden div with the next message before it's visible
// -------------------------------------------------------------------

pausescroller.prototype.setmessage = function()
{
	var scrollerinstance = this;
	if (this.mouseoverBol == 1) 		//if mouse is currently over scoller, do nothing (pause it)
		setTimeout(function(){scrollerinstance.setmessage()}, 100);
	else
	{
		var i = this.hiddendivpointer;
		var ceiling = this.content.length;
		this.hiddendivpointer = ( i+1 > ceiling - 1 ) ? 0 : i + 1;
		this.hiddendiv.innerHTML = this.content[this.hiddendivpointer];
		this.animateup();
	}
}

//get CSS padding value, if any
pausescroller.getCSSpadding = function(tickerobj)
{
	if (tickerobj.currentStyle)
		return tickerobj.currentStyle["paddingTop"];
	else 
		if (window.getComputedStyle)			//if DOM2
			return window.getComputedStyle(tickerobj, "").getPropertyValue("padding-top");
		else
			return 0;
}