//corrected by MH, 2010-11-07

var svgMainId = ""; //MH: globally store id of main SVG element to view
var svgScale;
var scaleFactor;
var originalWrapWidth;
var originalWrapHeight;
var wrapWrapWidth;
var wrapWrapHeight;

var rxLength = /^(\d+\.\d*|\d*\.\d+|\d+)(px|in|cm)?$/;





function GetLengthValue(s)
{
	if (s != null)
	{
		var m = rxLength.exec(s);
		
		if (m != null)
		{
			var w = parseFloat(m[1]);
			
			//	do inches conversion
			if (m[2] == "in")
				w *= 96;
			else if (m[2] == "cm")
				w = w * 96 / 2.54;
			
			return w;
		}
	}

	return null;
}





//svgId - contains XML id of the SVG element to be viewed // globally saved to svgMainId
//noWheel - if true, do not zoom
function InitPanAndZoom(svgId, noWheel) {

	if (typeof svgId == 'undefined' || svgId == null)
		svgId = "svgToView";

	svgMainId = svgId; //globally store id of main SVG element to view

	var svgElement = document.getElementById(svgId);
	if (!svgElement)
	{
		window.alert("INCORRECTLY inserted SVG object!\nCannot getElementById(\"" + svgId + "\")");
		return;
	}

	var svgWidth = GetLengthValue(svgElement.getAttribute("width"));
	if (svgWidth == null)
	{
		window.alert("Cannot get or parse width attribute of element \"" + svgId + "\"");
		return;
	}

	var svgHeight = GetLengthValue(svgElement.getAttribute("height"));
	if (svgHeight == null)
	{
		window.alert("Cannot get or parse height attribute of element \"" + svgId + "\"");
		return;
	}

	//	find initial SVG scale
	var svgScaleElement = document.getElementById("svgscale");
	if (!svgScaleElement)
	{
		window.alert("Cannot find element with id=\"svgscale\".");
		return;
	}

	var t = svgScaleElement.getAttribute("transform");
	if (t != null)
		svgScale = parseFloat(t.match(/scale\(\s*(\d+\.\d*|\d*\.\d+|\d+)/)[1]); // grab the first (or the one) scale value
	else
		svgScale = 1.0;

    //	get our viewBox width and height
    var vbw = svgWidth / svgScale;
    var vbh = svgHeight / svgScale;
    var svgViewBox = svgElement.getAttribute("viewBox");
    if (svgViewBox != null) {
        var vbm = svgViewBox.match(/0\s+0\s+([\+\-\.\d]+)\s+([\+\-\.\d]+)/);
        if (vbm != null) {
            vbw = parseFloat(vbm[1]);
            vbh = parseFloat(vbm[2]);
        }
    }

    //	ensure we have a viewBox attribute and no-op the scale
    svgElement.setAttribute("viewBox", "0 0 " + vbw.toString() + " " + vbh.toString());
    svgScaleElement.setAttribute("transform", "scale(1.0)");
    svgScale = 1.0;

	//	get the original size of the outer wrappers:
	//	offsetWidth is part of the MSIE's DHTML object model
	//	offsetWidth is not part of any W3C specification 
	//	also supported by Mozilla Gecko, Apple Webkit, Opera Presto
	wrapWrapWidth = document.getElementById("svgwrapwrap").offsetWidth;
	wrapWrapHeight = document.getElementById("svgwrapwrap").offsetHeight;

	var svgScaleToFill = Math.min(wrapWrapWidth / svgWidth, wrapWrapHeight / svgHeight);

	originalWrapWidth = Math.round(svgWidth * svgScaleToFill + 0.5);
	originalWrapHeight = Math.round(svgHeight * svgScaleToFill + 0.5);

	svgElement.setAttribute("width", originalWrapWidth.toString() + "px");
	svgElement.setAttribute("height", originalWrapHeight.toString() + "px");

	document.getElementById("svgwrap").style.width = svgElement.getAttribute("width");
	document.getElementById("svgwrap").style.height = svgElement.getAttribute("height");

	svgScale *= svgScaleToFill;
//	svgScaleElement.setAttribute("transform", "scale(" + svgScale.toString() + ")");

	//	initialize the drag object as code in ApplyScale is going to modify some stuff
	Drag.init(document.getElementById("svgwrap"));
	
	//	apply an initial scale of 1.0 to center the image
	ApplyScale(1.0);

	//	finally, make our wrapper and the svg it contains visible
	document.getElementById("svgwrap").style.visibility = "visible";

	if (typeof noWheel == 'undefined' || noWheel == false) {
	    if (window.addEventListener) {
	        document.getElementById("svgwrapwrap").addEventListener("mousewheel", ZoomWheel, false);
	        document.getElementById("svgwrapwrap").addEventListener("DOMMouseScroll", ZoomWheel, false);    // firefox
	    } else if (typeof window.attachEvent != 'undefined') {
	        document.getElementById("svgwrapwrap").attachEvent("onmousewheel", ZoomWheel);
	    }
	}

    //  init the zoom slider if we've got it
	var zoomSliderSlider = document.getElementById("slider");
	if (zoomSliderSlider != null)
	    zoomSliderSlider.onmousedown = SliderMouseDown;
}





var Animator = {

    startTime: null,
    startValue: null,
    endTime: null,
    endValue: null,
    intervalTime: Math.floor(1000 / 60),
    intervalID: null,
    valueChanger: null,

    stop: function() {
        if (Animator.intervalID != null)
            window.clearInterval(Animator.intervalID);
        Animator.intervalID = null;
    },

    onInterval: function() {
        var now = new Date().getTime();
        if (Animator.endTime <= now) {
            Animator.stop();
            Animator.valueChanger(Animator.endValue);
        } else {
            var percentDone = (now - Animator.startTime) / (Animator.endTime - Animator.startTime);
            Animator.valueChanger(Animator.startValue + (Animator.endValue - Animator.startValue) * percentDone);
        }
    },

    start: function(initialValue, endingValue, duration, changer) {
        this.stop();
        this.startValue = initialValue;
        this.endValue = endingValue;
        this.startTime = new Date().getTime();
        this.endTime = this.startTime + duration;
        this.valueChanger = changer;
        this.intervalID = window.setInterval(this.onInterval, this.intervalTime);
    }
}

function ZoomInOverTime(factor, milliseconds)
{
    Animator.start(scaleFactor, scaleFactor * factor, milliseconds, ApplyScale);
}

//	animation state
var aniStep;
var aniStartScale;
var aniInterval = null;

//	animates a 3x zoom over 10 steps
function AnimateZoomIn()
{
	if (++aniStep <= 10)
	{
		ApplyScale(aniStartScale * (1 + .2 * aniStep));
	}
	else
	{
		window.clearInterval(aniInterval);
		aniInterval = null;
	}
}

function ZoomIn()
{
	aniStep = 0;

	if (aniInterval != null)
		window.clearInterval(aniInterval);
	
	aniStartScale = scaleFactor;
	aniInterval = window.setInterval(AnimateZoomIn, 20);
}

//	animates a 3x zoom over 10 steps
function AnimateZoomOut()
{
	if (--aniStep >= -10)
	{
		ApplyScale(aniStartScale / (1 - .2 * aniStep));	// anistep is negative so this 1 to 3
	}
	else
	{
		window.clearInterval(aniInterval);
		aniInterval = null;
	}
}

function ZoomOut()
{
	aniStep = 0;

	if (aniInterval != null)
		window.clearInterval(aniInterval);

	aniStartScale = scaleFactor;
	aniInterval = window.setInterval(AnimateZoomOut, 20);
}

function Zoom1x()
{
	ApplyScale(1.0);
}

function ZoomFast(factor)
{
	ApplyScale(scaleFactor * factor);
}





function ApplyScale(newScale)
{
	if (newScale < 1/9)
		return;
	
	if (typeof(SliderZoomTo) != 'undefined')
	{
		//	limit to range 10% to 1000% for the slider
		newScale = Math.max(0.10, Math.min(10.0, newScale));

		if (newScale == scaleFactor)
			return;
			
		SliderZoomTo(newScale * 100, false);
	}

	scaleFactor = newScale;

	//	get the wrapping div
	var sw = document.getElementById("svgwrap");

	//	gather the old properties
	var oldw = sw.offsetWidth;
	var oldh = sw.offsetHeight;
	var oldl = sw.offsetLeft; //parseFloat(sw.style.left);
	var oldt = sw.offsetTop; //parseFloat(sw.style.top);

	//	compute the new width and height
	var neww = originalWrapWidth * newScale;
	var newh = originalWrapHeight * newScale;

	//	compute the new left and top
	var zoomCenterX = wrapWrapWidth / 2;
	var dx1 = zoomCenterX - oldl;
	var dx2 = dx1 * (neww / oldw);
	var newl = oldl + dx1 - dx2;
	var zoomCenterY = wrapWrapHeight / 2;
	var dy1 = zoomCenterY - oldt;
	var dy2 = dy1 * (newh / oldh);
	var newt = oldt + dy1 - dy2;

	//  fix the min and max X and Y for panning
	sw.minX = Math.min(wrapWrapWidth - neww, (wrapWrapWidth - neww) / 2);
	sw.maxX = Math.max(0, (wrapWrapWidth - neww) / 2);
	sw.minY = Math.min(wrapWrapHeight - newh, (wrapWrapHeight - newh) / 2);
	sw.maxY = Math.max(0, (wrapWrapHeight - newh) / 2);

	//  limit the new left and top to the new mins and maxes
	newl = Math.min(Math.max(newl, sw.minX), sw.maxX);
	newt = Math.min(Math.max(newt, sw.minY), sw.maxY);

	//	save all the property updating to last
	sw.style.width = neww.toString() + "px";
	sw.style.height = newh.toString() + "px";
	sw.style.left = newl.toString() + "px";
	sw.style.top = newt.toString() + "px";
	
	document.getElementById(svgMainId).setAttribute("width", neww.toString() + "px");
	document.getElementById(svgMainId).setAttribute("height", newh.toString() + "px");
	
	//  and, finally, update the svg scale factor
//	document.getElementById("svgscale").setAttribute("transform", "scale(" + (svgScale * newScale).toString() + ")");
}





function ZoomIt(delta)
{
	// only update if we'll make a change and don't let the new scalefactor get too small
	if (delta != 1 && 0.1 <= scaleFactor * delta)
	{
		ApplyScale(scaleFactor * delta);
	}
}





function ZoomWheel(e)
{
	if (typeof e == 'undefined') e = window.event;

	if (typeof e.wheelDelta != 'undefined')
	{
		if (e.wheelDelta > 0)
			ZoomIt(1.2);
		else if (e.wheelDelta < 0)
			ZoomIt(0.833333333);
	}
	else if (typeof e.detail != 'undefined')
	{
		if (e.detail < 0)
			ZoomIt(1.2);
		else if (e.detail > 0)
			ZoomIt(0.833333333);
	}

	return CancelEvent(e);
}





function CancelEvent(e) {
    e = e ? e : window.event;
    if (e.stopPropagation)
        e.stopPropagation();
    if (e.preventDefault)
        e.preventDefault();
    e.cancelBubble = true;
    e.cancel = true;
    e.returnValue = false;
    return false;
}





//  for the svg zoom slider control

function SliderZoomTo(zoom, applyTheZoom) {
		//  check for no slider
		if (document.getElementById("sliderControl") == null)
				return;

		//  fudge a little so that 100% is perfect
		if (97.5 <= zoom && zoom <= 102.5)
				zoom = 100;

		zoom = Math.round(zoom);
		document.getElementById("readout").firstChild.data = zoom.toString() + "%";

		var pos = ZoomToSliderPosition(zoom);
		document.getElementById("slidemover").setAttribute("transform", "translate(" + Math.round(pos).toString() + " 0)");

		if (applyTheZoom && typeof (ApplyScale) != 'undefined')
				ApplyScale(zoom / 100);
}





function ZoomToSliderPosition(zoom) {
		var partial = Math.pow(0.000108 * zoom + 0.000108 * Math.sqrt(Math.pow(zoom, 2) - 62.0042 * zoom + 1011.04) - 0.00334823, 1 / 3);
		return 132.283 * partial + 14.15 - 1.10453 / partial;
}





function SliderPositionToZoom(pos) {
		return 0.002 * Math.pow(pos, 3) - 0.0849 * Math.pow(pos, 2) + 2.078 * pos + 12.931;
}





function SliderZoomBy(fraction) {
		var zoom = parseFloat(document.getElementById("readout").firstChild.data);
		zoom = Math.max(10, Math.min(1000, Math.round(zoom * fraction)));
		SliderZoomTo(zoom, true);
}





function SliderKeyZoomBy(e, fraction) {
		if (e.keyCode == 32 || e.keyCode == 13) {
				SliderZoomBy(fraction);
				CancelEvent(e);
		}
}





function SliderKeySliderMove(e) {
		if (e.keyCode == 38 || e.keyCode == 39) {
				SliderZoomBy(1.1);  // up or right
				CancelEvent(e);
		}
		else if (e.keyCode == 40 || e.keyCode == 37) {
				SliderZoomBy(1 / 1.1);  // down or left
				CancelEvent(e);
		}
		else if (e.keyCode == 32 || e.keyCode == 13) {
				SliderZoomTo(100, true);   // space or enter does 100%
				CancelEvent(e);
		}
}





function SliderMouseDown(e) {

		var leftAdjust = 0;
		var op = document.getElementById("sliderControl");
		if (typeof (op.getBoundingClientRect) != 'undefined')
				leftAdjust = op.getBoundingClientRect().left;
		else {
				for (; op != null; op = op.offsetParent)
						leftAdjust += op.offsetLeft;
		}

		var zoneAdjust = parseFloat(document.getElementById("slidezone").getAttribute("transform").match(/\(\s*(\d+(\.\d*)?)/)[1]);
		zoneAdjust += parseFloat(document.getElementById("controlzone").getAttribute("transform").match(/\(\s*(\d+(\.\d*)?)/)[1]);

		document.onmousemove = function(e2) {
				var pos = Math.max(0, Math.min(91, e2.clientX - zoneAdjust - leftAdjust));
				var zoom = SliderPositionToZoom(pos);
				SliderZoomTo(zoom, true);
				CancelEvent(e2);
		};

		document.onmouseup = function(e2) {
				document.onmousemove = null;
				document.onmouseup = null;
				CancelEvent(e2);
		};

		CancelEvent(e);
}