var kShadowPadding = 17;

var kDefaultMagnifierSize = 0; // index into the arrays below

var kMagnifierSizes = new Array(0, 300);
var kMagnifierSizeNames = new Array('off', 'on');

var kControllerPrefix = 'magnifier: ';

//javascript:void(document.execCommand("BackgroundImageCache",false,true))


function MagnifierPosition()
{
	this.style.left = Math.round(this.normalImageX+this.xPosition - 1 - this.size/2) + "px"; // -1 to account for the border
	this.style.top = Math.round(this.normalImageY+this.yPosition - 1 - this.size/2) + "px";

	this.shadow.style.left = Math.round(this.normalImageX+this.xPosition - this.size/2 - kShadowPadding) + "px";
	this.shadow.style.top = Math.round(this.normalImageY+this.yPosition - this.size/2 - kShadowPadding) + "px";



	/*
	var magnifierCenterX = Math.round(this.xPosition * this.xMultiplier - this.size/2);
	var	magnifierCenterY = Math.round(this.yPosition * this.yMultiplier - this.size/2);
	*/



	var magnifierCenterX = Math.round(this.xPosition * this.xMultiplier - (this.size/2));
	var	magnifierCenterY = Math.round(this.yPosition * this.yMultiplier - (this.size/2));



	//alert(this.yMultiplier);
	//window.status=-magnifierCenterX + "px " + -magnifierCenterY + "px";

	this.style.backgroundPosition = -magnifierCenterX + "px " + -magnifierCenterY + "px";
}

function ControllerSizeButtonClick(event)
{
	if (!event) event = window.event;

	var button = event.currentTarget || event.srcElement;

	button.parentNode.magnifier.resize(button.magnifierSize);
}

function MagnifierResize(size)
{
	this.size = kMagnifierSizes[size];

	for (var i=0; i < this.controller.sizeButtons.length; i++)
	{
		if (i == size)
			this.controller.sizeButtons[i].className = "magnifierControllerButtonSelected";
		else
			this.controller.sizeButtons[i].className = "magnifierControllerButton";
	}

	if (this.size == 0)
	{
		this.shadow.style.display = "none";
		this.style.display = "none";
	}
	else
	{
		var shadow = this.shadow;
		var shadowSize = this.size + 2 * kShadowPadding;

		// MSIE 5.x/6.x must be treated specially in order to make them use the PNG alpha channel
		var shadowImageSrc = "/images/mainSite/shadow" + size + ".png";
		//alert(shadowImageSrc);
		if (shadow.runtimeStyle)
			shadow.runtimeStyle.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" +
										 shadowImageSrc +
										 "', sizingMethod='scale')";
		else
			shadow.style.backgroundImage = "url(" + shadowImageSrc + ")";
		shadow.style.width = shadowSize + "px";
		shadow.style.height = shadowSize + "px";
		shadow.style.display = "block";

		if (this.runtimeStyle) // msie counts the border as being part of the width
			this.size += 2; // must compensate

		this.style.width = this.size + "px";
		this.style.height = this.size + "px";
		this.style.display = "block";
		this.position();
	}
}

function MagnifierMouseDown(event)
{
	if (!event) event = window.event;

	document.body.magnifier = this;
	this.inDrag = true;
	if (event.pageX)
	{
		this.startX = event.pageX;
		this.startY = event.pageY;
	}
	else if (event.clientX)
	{
		this.startX = event.clientX;
		this.startY = event.clientY;
	}
	else
	{
		alert("don't know how to get position out of event");
		return;
	}
	this.savedCursor = this.style.cursor;
	this.style.cursor = "crosshair";
}

function MagnifierMouseUp()
{
	if (this.inDrag)
	{
		this.inDrag = false;
		this.style.cursor = this.savedCursor;
		document.body.magnifier = null;
	}
}

function MagnifierDrag(event)
{
	if (!event) event = window.event;
	var magnifier = this.magnifier; // we're actually in the body's onmousemove handler

	if (magnifier && magnifier.inDrag)
	{
		var eventX;
		var eventY;

		if (event.pageX)
		{
			eventX = event.pageX;
			eventY = event.pageY;
		}
		else if (event.clientX)
		{
			eventX = event.clientX;
			eventY = event.clientY;
		}
		else
		{
			return;
		}

		magnifier.xPosition += eventX - magnifier.startX;
		magnifier.yPosition += eventY - magnifier.startY;

		magnifier.startX = eventX;
		magnifier.startY = eventY;

		magnifier.position();
	}
}

function createMagnifier(started, baseID, zoomedURL, zoomedWidth, zoomedHeight)
{
	//alert("zoomed height1: "+zoomedHeight);
	if(!started)
	{
		this.zoomedImage = document.createElement("img");
		zoomedImage.src = zoomedURL;
		started=true;
	}

	var waitDiv=document.getElementById("zoomWaiting");

	if(zoomedImage.complete)
	{
		loadMagnifier(baseID, this.zoomedImage, zoomedWidth, zoomedHeight);
		waitDiv.style.display="none";
	}
	else
	{

		var timeoutCall="createMagnifier(true, '"+baseID+"', '"+zoomedURL+"', "+zoomedWidth+", "+zoomedHeight+")";
		setTimeout(timeoutCall, 1000);
	}
}

function loadMagnifier(baseID, zoomedImage, zoomedWidth, zoomedHeight)
{
	// get the zoomed image (load as early as possible)

	// get the div's
	var base = document.getElementById(baseID);


	var magnifier = document.createElement("div");

	// get the regular image
	var normalImage = null;
	for (var i=0; i < base.childNodes.length; i++)
	{
		if (base.childNodes[i].tagName &&
			base.childNodes[i].tagName.toLowerCase() == "img")
		{
			normalImage = base.childNodes[i];
			break;
		}
	}

	if (normalImage == null)
	{
		alert("couldn't find normal image for magnifier " + baseID);
		return;
	}

	magnifier.normalImageX=findPosX(normalImage);
	magnifier.normalImageY=findPosY(normalImage);



	/*
	var s="";
	for(var i=0; i<base.attributes.length; i++)
	{
		node=base.attributes.item(i);
		s+=node.nodeName+":"+node.nodeValue+"\n";
	}
	alert(s);
	this.normaImageXOffset=base.clientLeft;
	*/



	magnifier.xMultiplier = zoomedWidth/normalImage.width;
	magnifier.yMultiplier = zoomedHeight/normalImage.height;

	magnifier.size = kMagnifierSizes[kDefaultMagnifierSize];
	magnifier.xPosition = normalImage.width/2 - 60;
	magnifier.yPosition = normalImage.height/2 - 10;

	magnifier.id = baseID + "Magnifier";
	magnifier.className = "magnifier";

	// styles (only dynamic ones, rest are part of the class)
	magnifier.style.backgroundImage = "url(" + zoomedImage.src + ")";

	// functions
	magnifier.onmousedown = MagnifierMouseDown;
	magnifier.onmouseup = MagnifierMouseUp;
	document.body.onmousemove = MagnifierDrag; // we attach this handler to the body because if the user moves
											   // the mouse fast enough, it'll go outside the boundaries of the
											   // magnifier, and then the magnifier's mousemove handler won't fire

	magnifier.position = MagnifierPosition;
	magnifier.resize = MagnifierResize;

	// controller
	var controller = document.createElement("span");

	controller.id = baseID + "MagnifierController";
	controller.className = "magnifierController";

	var controllerPrefix = document.createElement("span");
	controllerPrefix.innerHTML = kControllerPrefix;

	controllerPrefix.className = "magnifierControllerPrefix";
	controller.appendChild(controllerPrefix);

	controller.sizeButtons = new Array(kMagnifierSizes.length);



	for (var i=0; i < kMagnifierSizes.length; i++)
	{
		var button = document.createElement("span");
		button.innerHTML = kMagnifierSizeNames[i];
		button.className = "magnifierControllerButton";
		button.onclick = ControllerSizeButtonClick;
		button.magnifierSize = i;

		controller.sizeButtons[i] = button;
		controller.appendChild(button);
	}

	// shadow
	var shadow = document.createElement("div");

	shadow.id = baseID + "MagnifierShadow";
	shadow.className = "magnifierShadow";

	// point objects at each other
	magnifier.controller = controller;
	controller.magnifier = magnifier;
	magnifier.shadow = shadow;

	// add to document and lay out

	var controllerContainer = document.createElement("div");

	controllerContainer.className = "magnifierControllerContainer";

	controllerContainer.appendChild(controller);

	base.insertBefore(controllerContainer, document.getElementById("message"));
	base.appendChild(shadow);
	base.appendChild(magnifier);
	magnifier.resize(kDefaultMagnifierSize); // also positions
}

function findPosX(obj)
  {
	var curleft = 0;
	if(obj.offsetParent)
		while(1)
		{
		  curleft += obj.offsetLeft;
		  if(!obj.offsetParent)
			break;
		  obj = obj.offsetParent;
		}
	else if(obj.x)
		curleft += obj.x;
	return curleft;
  }

  function findPosY(obj)
  {
	var curtop = 0;
	if(obj.offsetParent)
		while(1)
		{
		  curtop += obj.offsetTop;
		  if(!obj.offsetParent)
			break;
		  obj = obj.offsetParent;
		}
	else if(obj.y)
		curtop += obj.y;
	return curtop;
  }