var ZoomItem = null;

var CLHidden = 0;
var CLLoading = 1;
var CLZoomIn = 2;
var CLZoomed = 3;
var CLZoomOut = 4;

var valign = 'middle';
var halign = 'center';

function CZoom()
{
	if (ZoomItem) return;
	this.BorderWidth = 1;
	this.TimeSpan = 500;
	this.TimerInterval = 40;
	this.HideSmall = false;
	this.TimeModifyFunc = null;
	this.Enabled = true;
	this.VMargin = 0;
	this.HMargin = 0;
	this.SmallPosX = 0;
	this.SmallPosY = 0;
	this.SmallWidth = 0;
	this.SmallHeight = 0;
	this.BigPosX = 0;
	this.BigPosY = 0;
	this.BigWidth = 0;
	this.BigHeight = 0;
	this.StartTime = 0;
	this.Timer = null;
	this.BigImgID = -1;
	this.SmallImg = null;
	this.WaitObj = null;
	this.ZoomImg = null;
	this.State = CLHidden;
	this.HtmlWritten = false;
	ZoomItem = this;
}

function ZoomPreload() { ZoomItem.Preload(ZoomPreload.arguments); }
function ZoomPreloadList(aUrlList) { ZoomItem.Preload(aUrlList); }
function ZoomHTML(v, h)
{
	halign = h;
	valign = v;
	ZoomItem.HTML();
}

function ZoomImage(aImgName, aBigImgUrl)
{
	ZoomItem.Zoom(aImgName, aBigImgUrl);
	SetEclipseAreaFilter('Gray()');
}

function SetEclipseAreaFilter(filter)
{
	var eclipseArea = xGetElementById("EclipseArea");

	if (eclipseArea != null)
		eclipseArea.style.filter = filter;
}

function ZoomEnable() { ZoomItem.Enable(); }
function ZoomDisable() { ZoomItem.Disable(); }

CZoom.prototype.Preload = function(aImgUrlList)
{
	IC.PreloadImages( aImgUrlList );
}

CZoom.prototype.HTML = function()
{
	if (this.HtmlWritten)
		return;

	var s = '<img id="ZoomPic" class="zoomed" src="" style="position:absolute;visibility:hidden;z-index:100;';
	s += '" onclick="ZoomItem.UnZoom()">'
	document.writeln( s );
	this.HtmlWritten = true;
}

CZoom.prototype.Zoom = function(aImgName, aBigImgUrl)
{
	if (!this.Enabled)
		return;

	this.WaitObj = xGetElementById("ZoomPicWait");
	this.ZoomImg = xGetElementById("ZoomPic");
	var bigImgID = IC.FindImage(aBigImgUrl);

	if ((this.State != CLHidden) && (bigImgID != -1) && (bigImgID == this.BigImgID))
	{
		if (this.State == CLLoading)
		{
			xHide( this.WaitObj );
			this.State = CLHidden;
			return;
		}

		if (this.State == CLZoomIn || this.State == CLZoomed)
		{
			this.UnZoom();
			return;
		}

		if (this.Timer)
		{
			clearTimeout( this.Timer );
			this.Timer = null;
		}

		this.StartTime = xTimeMS() - this.TimeSpan + (xTimeMS() - this.StartTime);
		this.State = CLZoomIn;
		var me = this;
		this.Timer = setTimeout(function(){me.Enlarge();}, this.TimerInterval);
		return;
	}

	if (this.State == CLLoading)
	{
		xHide( this.WaitObj );
		this.State = CLHidden;
	}
	else if (this.State != CLHidden)
	{
		if (this.Timer)
		{
			clearTimeout( this.Timer );
			this.Timer = null;
		}
		this.HideZoomImg();
	}

	this.SmallImg = xGetElementById(aImgName);
	
	if ((bigImgID != -1) && IC.IsLoaded(bigImgID))
	{
		this.BigImgID = bigImgID;
		this.StartZoom();
	}
	else
	{
		this.GetSmallImgData();
		var y = (this.SmallHeight - 21);
		xMoveTo( this.WaitObj, this.SmallPosX+3, this.SmallPosY+y );
		xShow( this.WaitObj );
		this.State = CLLoading;
		var me = this;
		this.BigImgID = IC.LoadImage( aBigImgUrl, function(aImgID){me.OnLoad(aImgID);} );
	}
}

CZoom.prototype.Enable = function() { this.Enabled = true; }
CZoom.prototype.Disable = function() { this.Enabled = false; }

CZoom.prototype.GetSmallImgData = function()
{
	this.SmallWidth = this.SmallImg.width + 2*this.BorderWidth;
	this.SmallHeight = this.SmallImg.height + 2*this.BorderWidth;
	this.SmallPosX = xPageX(this.SmallImg) + (xWidth(this.SmallImg)-this.SmallWidth)/2; // Ränder berücksichtigen
	this.SmallPosY = xPageY(this.SmallImg) + (xHeight(this.SmallImg)-this.SmallHeight)/2;
}

CZoom.prototype.OnLoad = function( aImgID )
{
	if ((this.State == CLLoading) && (this.BigImgID == aImgID))
		this.StartZoom();
}

CZoom.prototype.Range = function( aValue, aMin, aMax )
{
	return aMin + (aMax-aMin)*aValue;
}

CZoom.prototype.StartZoom = function()
{
	this.BigImg = IC.Image(this.BigImgID);
	this.ZoomImg.src = this.BigImg.src;
	this.GetSmallImgData();
	this.BigWidth = this.BigImg.width + 2*this.BorderWidth;
	this.BigHeight = this.BigImg.height + 2*this.BorderWidth;
	
	if ((this.SmallWidth >= this.BigWidth) || (this.SmallHeight >= this.BigHeight))
		return;

	var clW = xClientWidth();
	var clX = xScrollLeft();
	if (halign == 'left')
	{
		this.BigPosX = this.SmallPosX - this.BigWidth + this.SmallWidth - this.BorderWidth;
		if ((this.BigPosX+this.BigWidth) > (clX+clW)) this.BigPosX = (clX+clW) - this.BigWidth;
		if ((this.BigPosX)               < (clX)    ) this.BigPosX =  clX;
	}
	else if (halign == 'right')
	{
		this.BigPosX = this.SmallPosX + this.BorderWidth;
		if ((this.BigPosX) < (clX)) this.BigPosX =  clX;
	}
	else
	{
		var dxCenter = 1;
		if (this.BigWidth <= clW)
		{
			dxCenter = (this.BigWidth-this.SmallWidth)/(clW-this.SmallWidth);
			if (dxCenter < 0) dxCenter = 0;
		}

		if (halign == 'tocenter') dxCenter = 1;
		var cxBig = clW / 2;
		var cxSmall = this.SmallPosX-clX + (this.SmallWidth/2);
		var cx = dxCenter*(cxBig-cxSmall)+cxSmall;
		this.BigPosX = clX + cx - this.BigWidth/2;
		if (this.BigPosX < 0) this.BigPosX = 0;
		if (this.BigWidth <= clW)
		{
			if ((this.BigPosX+this.BigWidth) > (clX+clW)) this.BigPosX = (clX+clW) - this.BigWidth;
			if ((this.BigPosX)               < (clX)    ) this.BigPosX =  clX;
		}
	}

	var clH = xClientHeight();
	var clY = xScrollTop();

	if (valign == 'top')
	{
		this.BigPosY = this.SmallPosY - this.BigHeight + this.SmallHeight - this.BorderWidth;
		if ((this.BigPosY+this.BigHeight) > (clY+clH)) this.BigPosY = (clY+clH) - this.BigHeight;
		if ((this.BigPosY)                < (clY)    ) this.BigPosY =  clY;
	}
	else if (valign == 'bottom')
	{
		this.BigPosY = this.SmallPosY + this.BorderWidth;
		if ((this.BigPosY) < (clY)) this.BigPosY =  clY;
	}
	else
	{
		var dyCenter = 1;
		if (this.BigHeight <= clH)
		{
			dyCenter = (this.BigHeight-this.SmallHeight)/(clH-this.SmallHeight);
			if (dyCenter < 0) dyCenter = 0;
		}

		if (valign == 'tomiddle') dyCenter = 1;
		var cyBig = clH / 2;
		var cySmall = this.SmallPosY-clY + (this.SmallHeight/2);
		var cy = dyCenter*(cyBig-cySmall)+cySmall;
		this.BigPosY = clY + cy - this.BigHeight/2;
		if (this.BigPosY < 0) this.BigPosY = 0;
	
		if (this.BigHeight <= clH)
		{
			if ((this.BigPosY+this.BigHeight) > (clY+clH)) this.BigPosY = (clY+clH) - this.BigHeight;
			if ((this.BigPosY)                < (clY)    ) this.BigPosY =  clY;
		}
	}

	this.StartTime = xTimeMS();
	var me = this;
	this.Timer = setTimeout(function(){me.Enlarge();}, this.TimerInterval);
}

CZoom.prototype.Enlarge = function()
{
	if (this.Timer)
	{
		clearTimeout(this.Timer);
		this.Timer = null;
	}

	var param = (xTimeMS() - this.StartTime) / this.TimeSpan;
	var eom = param >= 1;
	if (param > 1) param = 1;
	if (this.TimeModifyFunc) param = this.TimeModifyFunc(param);
	if (param < 0) param = 0;
	if (param > 1) param = 1;
	var x = this.Range( param, this.SmallPosX, this.BigPosX );
	var y = this.Range( param, this.SmallPosY, this.BigPosY );
	var w = this.Range( param, this.SmallWidth, this.BigWidth );
	var h = this.Range( param, this.SmallHeight, this.BigHeight );
	xMoveTo( this.ZoomImg, x, y );
	xResizeTo( this.ZoomImg, w, h );

	if (this.State != CLZoomIn)
	{
		xHide( this.WaitObj );
		xShow( this.ZoomImg );
		if (this.HideSmall) xHide( this.SmallImg );
		this.State = CLZoomIn;
	}
	var me = this;
	if (eom)
	{
		this.State = CLZoomed;
		this.Timer = setTimeout(function(){me.CheckOutOfWindow();}, 200);
	}
	else
	{
		this.Timer = setTimeout(function(){me.Enlarge();}, this.TimerInterval);
	}
}

CZoom.prototype.CheckOutOfWindow = function()
{
	var space = (xClientHeight()-this.BigHeight) / 2;
	var newY = xScrollTop() + space;
	var toleranz;

	if (space > 0)
		toleranz = space + (this.BigHeight * 2 / 3);
	else
		toleranz = -space + (xClientHeight() * 2 / 3);

	if (Math.abs(newY-this.BigPosY) > toleranz)
	{
		this.UnZoom();
		return;
	}
	var me = this;
	this.Timer = setTimeout(function(){me.CheckOutOfWindow();}, 200);
}

CZoom.prototype.NewWindow = function()
{
	if (this.HideSmall) xShow( this.SmallImg );
	xHide( this.ZoomImg );
	xMoveTo( this.ZoomImg, 0, 0 );
	xResizeTo( this.ZoomImg, 0, 0 );
	this.State = CLHidden;
	location.href = IC.ImageUrl(this.BigImgID);
}

CZoom.prototype.UnZoom = function()
{
	SetEclipseAreaFilter('none');

	if (this.State == CLHidden || this.State == CLZoomOut) return;

	if (this.State == CLLoading)
	{
		xHide( this.WaitObj );
		this.State = CLHidden;
		return;
	}

	if (this.Timer)
	{
		clearTimeout(this.Timer);
		this.Timer = null;
	}

	this.SmallPosX = xPageX(this.SmallImg) + (xWidth(this.SmallImg)-this.SmallWidth)/2; // Ränder berücksichtigen
	this.SmallPosY = xPageY(this.SmallImg) + (xHeight(this.SmallImg)-this.SmallHeight)/2;

	if (this.State == CLZoomIn)
		this.StartTime = xTimeMS() - this.TimeSpan + (xTimeMS() - this.StartTime);
	else
		this.StartTime = xTimeMS();

	this.State = CLZoomOut;
	var me = this;
	this.Timer = setTimeout(function(){me.Shrink();}, this.TimerInterval);
}

CZoom.prototype.HideZoomImg = function()
{
	if (this.HideSmall) xShow( this.SmallImg );
	xHide( this.ZoomImg );
	xMoveTo( this.ZoomImg, 0, 0 );
	xResizeTo( this.ZoomImg, 0, 0 );
	this.State = CLHidden;
}

CZoom.prototype.Shrink = function()
{
	if (this.Timer)
	{
		clearTimeout(this.Timer);
		this.Timer = null;
	}
	var param = (xTimeMS() - this.StartTime) / this.TimeSpan;
	var eom = param >= 1;
	if (param > 1) param = 1;
	if (this.TimeModifyFunc) param = this.TimeModifyFunc(param);
	if (param < 0) param = 0;
	if (param > 1) param = 1;
	var x = this.Range( param, this.BigPosX, this.SmallPosX );
	var y = this.Range( param, this.BigPosY, this.SmallPosY );
	var w = this.Range( param, this.BigWidth, this.SmallWidth );
	var h = this.Range( param, this.BigHeight, this.SmallHeight );
	xMoveTo( this.ZoomImg, x, y );
	xResizeTo( this.ZoomImg, w, h );

	if (eom)
	{
		this.HideZoomImg();
	}
	else
	{
		xMoveTo( this.ZoomImg, x, y );
		xResizeTo( this.ZoomImg, w, h );
		var me = this;
		this.Timer = setTimeout(function(){me.Shrink();}, this.TimerInterval);
	}
}

ZoomItem = new CZoom();
ZoomItem.TimeModifyFunc = function( aValue ) { return (0.5 - 0.5 * Math.cos(Math.PI*aValue)); }