var kShadowPadding = 17;

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

var kMagnifierSizes = new Array(0, 100, 150);
var kMagnifierSizeNames = new Array('zapnout', '','vypnout');

var kControllerPrefix = '';


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

	/*
	this.style.left = Math.round(this.xPosition - 1 - this.size/2) + "px"; // -1 to account for the border
	this.style.top = Math.round(this.yPosition - 1 - this.size/2) + "px";
	
	this.shadow.style.left = Math.round(this.xPosition - this.size/2 - kShadowPadding) + "px";
	this.shadow.style.top = Math.round(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);
	*/
		
	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 = "shadow" + size + ".png";
		if (shadow.runtimeStyle)
			shadow.runtimeStyle.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" +
											 shadowImageSrc +
										 "', sizingMethod='scale')";
		else
			shadow.style.backgroundImage = "url(./images/" + 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 loadMagnifier(baseID, zoomedURL, zoomedWidth, zoomedHeight)
		{
			// get the zoomed image (load as early as possible)
			var zoomedImage = document.createElement("img");
			zoomedImage.src = zoomedURL;
			
			// 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.xMultiplier = zoomedWidth/normalImage.width;
			magnifier.yMultiplier = zoomedHeight/normalImage.height;
			
			magnifier.size = kMagnifierSizes[kDefaultMagnifierSize];
			magnifier.xPosition = normalImage.width /2;
			magnifier.yPosition = normalImage.height /2;
			
			magnifier.id = baseID + "Magnifier";
			magnifier.className = "magnifier";
			
			// styles (only dynamic ones, rest are part of the class)
			magnifier.style.backgroundImage = "url(" + zoomedURL + ")";
			
			// 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 vypniLupu() {
	document.getElementById('bindingMagnifierController').magnifier.resize(0);
	document.getElementById('on').style.visibility = "visible";
	document.getElementById('off').style.visibility = "hidden";
}

function zapniLupu() {
	document.getElementById('bindingMagnifierController').magnifier.resize(2);
	document.getElementById('on').style.visibility = "hidden";
	document.getElementById('off').style.visibility = "visible";

}