svgedit/editor/svgutils.js

/* eslint-disable no-var */
/* globals $, svgedit, unescape, DOMParser, ActiveXObject, getStrokedBBox, RGBColor */
/**
 * Package: svgedit.utilities
 *
 * Licensed under the MIT License
 *
 * Copyright(c) 2010 Alexis Deveria
 * Copyright(c) 2010 Jeff Schiller
 */

// Dependencies:
// 1) jQuery
// 2) pathseg.js
// 3) browser.js
// 4) svgtransformlist.js
// 5) units.js

(function (undef) {
'use strict';

if (!svgedit.utilities) {
	svgedit.utilities = {};
}

// Constants

// String used to encode base64.
var KEYSTR = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
var NS = svgedit.NS;

// Much faster than running getBBox() every time
var visElems = 'a,circle,ellipse,foreignObject,g,image,line,path,polygon,polyline,rect,svg,text,tspan,use';
var visElemsArr = visElems.split(',');
// var hidElems = 'clipPath,defs,desc,feGaussianBlur,filter,linearGradient,marker,mask,metadata,pattern,radialGradient,stop,switch,symbol,title,textPath';

var editorContext_ = null;
var domdoc_ = null;
var domcontainer_ = null;
var svgroot_ = null;

svgedit.utilities.init = function (editorContext) {
	editorContext_ = editorContext;
	domdoc_ = editorContext.getDOMDocument();
	domcontainer_ = editorContext.getDOMContainer();
	svgroot_ = editorContext.getSVGRoot();
};

// Function: svgedit.utilities.toXml
// Converts characters in a string to XML-friendly entities.
//
// Example: '&' becomes '&'
//
// Parameters:
// str - The string to be converted
//
// Returns:
// The converted string
svgedit.utilities.toXml = function (str) {
	// ' is ok in XML, but not HTML
	// > does not normally need escaping, though it can if within a CDATA expression (and preceded by "]]")
	return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/, '&#x27;');
};

// Function: svgedit.utilities.fromXml
// Converts XML entities in a string to single characters.
// Example: '&amp;' becomes '&'
//
// Parameters:
// str - The string to be converted
//
// Returns:
// The converted string
svgedit.utilities.fromXml = function (str) {
	return $('<p/>').html(str).text();
};

// This code was written by Tyler Akins and has been placed in the
// public domain.  It would be nice if you left this header intact.
// Base64 code from Tyler Akins -- http://rumkin.com

// schiller: Removed string concatenation in favour of Array.join() optimization,
//				also precalculate the size of the array needed.

// Function: svgedit.utilities.encode64
// Converts a string to base64
svgedit.utilities.encode64 = function (input) {
	// base64 strings are 4/3 larger than the original string
	input = svgedit.utilities.encodeUTF8(input); // convert non-ASCII characters
	// input = svgedit.utilities.convertToXMLReferences(input);
	if (window.btoa) {
		return window.btoa(input); // Use native if available
	}
	var output = [];
	output.length = Math.floor((input.length + 2) / 3) * 4;
	var chr1, chr2, chr3;
	var enc1, enc2, enc3, enc4;
	var i = 0, p = 0;

	do {
		chr1 = input.charCodeAt(i++);
		chr2 = input.charCodeAt(i++);
		chr3 = input.charCodeAt(i++);

		enc1 = chr1 >> 2;
		enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
		enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
		enc4 = chr3 & 63;

		if (isNaN(chr2)) {
			enc3 = enc4 = 64;
		} else if (isNaN(chr3)) {
			enc4 = 64;
		}

		output[p++] = KEYSTR.charAt(enc1);
		output[p++] = KEYSTR.charAt(enc2);
		output[p++] = KEYSTR.charAt(enc3);
		output[p++] = KEYSTR.charAt(enc4);
	} while (i < input.length);

	return output.join('');
};

// Function: svgedit.utilities.decode64
// Converts a string from base64
svgedit.utilities.decode64 = function (input) {
	if (window.atob) {
		return svgedit.utilities.decodeUTF8(window.atob(input));
	}
	var output = '';
	var chr1, chr2, chr3 = '';
	var enc1, enc2, enc3, enc4 = '';
	var i = 0;

	// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
	input = input.replace(/[^A-Za-z0-9+/=]/g, '');

	do {
		enc1 = KEYSTR.indexOf(input.charAt(i++));
		enc2 = KEYSTR.indexOf(input.charAt(i++));
		enc3 = KEYSTR.indexOf(input.charAt(i++));
		enc4 = KEYSTR.indexOf(input.charAt(i++));

		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;

		output = output + String.fromCharCode(chr1);

		if (enc3 !== 64) {
			output = output + String.fromCharCode(chr2);
		}
		if (enc4 !== 64) {
			output = output + String.fromCharCode(chr3);
		}

		chr1 = chr2 = chr3 = '';
		enc1 = enc2 = enc3 = enc4 = '';
	} while (i < input.length);
	return svgedit.utilities.decodeUTF8(output);
};

svgedit.utilities.decodeUTF8 = function (argString) {
	return decodeURIComponent(escape(argString));
};

// codedread:does not seem to work with webkit-based browsers on OSX // Brettz9: please test again as function upgraded
svgedit.utilities.encodeUTF8 = function (argString) {
	return unescape(encodeURIComponent(argString));
};

/**
 * convert dataURL to object URL
 * @param {string} dataurl
 * @return {string} object URL or empty string
 */
svgedit.utilities.dataURLToObjectURL = function (dataurl) {
	if (typeof Uint8Array === 'undefined' || typeof Blob === 'undefined' || typeof URL === 'undefined' || !URL.createObjectURL) {
		return '';
	}
	var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
		bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
	while (n--) {
		u8arr[n] = bstr.charCodeAt(n);
	}
	var blob = new Blob([u8arr], {type: mime});
	return URL.createObjectURL(blob);
};

/**
 * get object URL for a blob object
 * @param {Blob} blob A Blob object or File object
 * @return {string} object URL or empty string
 */
svgedit.utilities.createObjectURL = function (blob) {
	if (!blob || typeof URL === 'undefined' || !URL.createObjectURL) {
		return '';
	}
	return URL.createObjectURL(blob);
};

/**
 * @property {string} blankPageObjectURL
 */
svgedit.utilities.blankPageObjectURL = (function () {
	if (typeof Blob === 'undefined') {
		return '';
	}
	var blob = new Blob(['<html><head><title>SVG-edit</title></head><body>&nbsp;</body></html>'], {type: 'text/html'});
	return svgedit.utilities.createObjectURL(blob);
})();

// Function: svgedit.utilities.convertToXMLReferences
// Converts a string to use XML references
svgedit.utilities.convertToXMLReferences = function (input) {
	var n,
		output = '';
	for (n = 0; n < input.length; n++) {
		var c = input.charCodeAt(n);
		if (c < 128) {
			output += input[n];
		} else if (c > 127) {
			output += ('&#' + c + ';');
		}
	}
	return output;
};

// Function: svgedit.utilities.text2xml
// Cross-browser compatible method of converting a string to an XML tree
// found this function here: http://groups.google.com/group/jquery-dev/browse_thread/thread/c6d11387c580a77f
svgedit.utilities.text2xml = function (sXML) {
	if (sXML.indexOf('<svg:svg') >= 0) {
		sXML = sXML.replace(/<(\/?)svg:/g, '<$1').replace('xmlns:svg', 'xmlns');
	}

	var out, dXML;
	try {
		dXML = (window.DOMParser) ? new DOMParser() : new ActiveXObject('Microsoft.XMLDOM');
		dXML.async = false;
	} catch (e) {
		throw new Error('XML Parser could not be instantiated');
	}
	try {
		if (dXML.loadXML) {
			out = (dXML.loadXML(sXML)) ? dXML : false;
		} else {
			out = dXML.parseFromString(sXML, 'text/xml');
		}
	} catch (e2) { throw new Error('Error parsing XML string'); }
	return out;
};

// Function: svgedit.utilities.bboxToObj
// Converts a SVGRect into an object.
//
// Parameters:
// bbox - a SVGRect
//
// Returns:
// An object with properties names x, y, width, height.
svgedit.utilities.bboxToObj = function (bbox) {
	return {
		x: bbox.x,
		y: bbox.y,
		width: bbox.width,
		height: bbox.height
	};
};

// Function: svgedit.utilities.walkTree
// Walks the tree and executes the callback on each element in a top-down fashion
//
// Parameters:
// elem - DOM element to traverse
// cbFn - Callback function to run on each element
svgedit.utilities.walkTree = function (elem, cbFn) {
	if (elem && elem.nodeType === 1) {
		cbFn(elem);
		var i = elem.childNodes.length;
		while (i--) {
			svgedit.utilities.walkTree(elem.childNodes.item(i), cbFn);
		}
	}
};

// Function: svgedit.utilities.walkTreePost
// Walks the tree and executes the callback on each element in a depth-first fashion
// TODO: FIXME: Shouldn't this be calling walkTreePost?
//
// Parameters:
// elem - DOM element to traverse
// cbFn - Callback function to run on each element
svgedit.utilities.walkTreePost = function (elem, cbFn) {
	if (elem && elem.nodeType === 1) {
		var i = elem.childNodes.length;
		while (i--) {
			svgedit.utilities.walkTree(elem.childNodes.item(i), cbFn);
		}
		cbFn(elem);
	}
};

// Function: svgedit.utilities.getUrlFromAttr
// Extracts the URL from the url(...) syntax of some attributes.
// Three variants:
//  * <circle fill="url(someFile.svg#foo)" />
//  * <circle fill="url('someFile.svg#foo')" />
//  * <circle fill='url("someFile.svg#foo")' />
//
// Parameters:
// attrVal - The attribute value as a string
//
// Returns:
// String with just the URL, like someFile.svg#foo
svgedit.utilities.getUrlFromAttr = function (attrVal) {
	if (attrVal) {
		// url("#somegrad")
		if (attrVal.indexOf('url("') === 0) {
			return attrVal.substring(5, attrVal.indexOf('"', 6));
		}
		// url('#somegrad')
		if (attrVal.indexOf("url('") === 0) {
			return attrVal.substring(5, attrVal.indexOf("'", 6));
		}
		if (attrVal.indexOf('url(') === 0) {
			return attrVal.substring(4, attrVal.indexOf(')'));
		}
	}
	return null;
};

// Function: svgedit.utilities.getHref
// Returns the given element's xlink:href value
svgedit.utilities.getHref = function (elem) {
	return elem.getAttributeNS(NS.XLINK, 'href');
};

// Function: svgedit.utilities.setHref
// Sets the given element's xlink:href value
svgedit.utilities.setHref = function (elem, val) {
	elem.setAttributeNS(NS.XLINK, 'xlink:href', val);
};

// Function: findDefs
//
// Returns:
// The document's <defs> element, create it first if necessary
svgedit.utilities.findDefs = function () {
	var svgElement = editorContext_.getSVGContent();
	var defs = svgElement.getElementsByTagNameNS(NS.SVG, 'defs');
	if (defs.length > 0) {
		defs = defs[0];
	} else {
		defs = svgElement.ownerDocument.createElementNS(NS.SVG, 'defs');
		if (svgElement.firstChild) {
			// first child is a comment, so call nextSibling
			svgElement.insertBefore(defs, svgElement.firstChild.nextSibling);
		} else {
			svgElement.appendChild(defs);
		}
	}
	return defs;
};

// TODO(codedread): Consider moving the next to functions to bbox.js

// Function: svgedit.utilities.getPathBBox
// Get correct BBox for a path in Webkit
// Converted from code found here:
// http://blog.hackers-cafe.net/2009/06/how-to-calculate-bezier-curves-bounding.html
//
// Parameters:
// path - The path DOM element to get the BBox for
//
// Returns:
// A BBox-like object
svgedit.utilities.getPathBBox = function (path) {
	var seglist = path.pathSegList;
	var tot = seglist.numberOfItems;

	var bounds = [[], []];
	var start = seglist.getItem(0);
	var P0 = [start.x, start.y];

	var i;
	for (i = 0; i < tot; i++) {
		var seg = seglist.getItem(i);

		if (seg.x === undef) { continue; }

		// Add actual points to limits
		bounds[0].push(P0[0]);
		bounds[1].push(P0[1]);

		if (seg.x1) {
			var P1 = [seg.x1, seg.y1],
				P2 = [seg.x2, seg.y2],
				P3 = [seg.x, seg.y];

			var j;
			for (j = 0; j < 2; j++) {
				var calc = function (t) {
					return Math.pow(1 - t, 3) * P0[j] +
						3 * Math.pow(1 - t, 2) * t * P1[j] +
						3 * (1 - t) * Math.pow(t, 2) * P2[j] +
						Math.pow(t, 3) * P3[j];
				};

				var b = 6 * P0[j] - 12 * P1[j] + 6 * P2[j];
				var a = -3 * P0[j] + 9 * P1[j] - 9 * P2[j] + 3 * P3[j];
				var c = 3 * P1[j] - 3 * P0[j];

				if (a === 0) {
					if (b === 0) {
						continue;
					}
					var t = -c / b;
					if (t > 0 && t < 1) {
						bounds[j].push(calc(t));
					}
					continue;
				}
				var b2ac = Math.pow(b, 2) - 4 * c * a;
				if (b2ac < 0) { continue; }
				var t1 = (-b + Math.sqrt(b2ac)) / (2 * a);
				if (t1 > 0 && t1 < 1) { bounds[j].push(calc(t1)); }
				var t2 = (-b - Math.sqrt(b2ac)) / (2 * a);
				if (t2 > 0 && t2 < 1) { bounds[j].push(calc(t2)); }
			}
			P0 = P3;
		} else {
			bounds[0].push(seg.x);
			bounds[1].push(seg.y);
		}
	}

	var x = Math.min.apply(null, bounds[0]);
	var w = Math.max.apply(null, bounds[0]) - x;
	var y = Math.min.apply(null, bounds[1]);
	var h = Math.max.apply(null, bounds[1]) - y;
	return {
		'x': x,
		'y': y,
		'width': w,
		'height': h
	};
};

// Function: groupBBFix
// Get the given/selected element's bounding box object, checking for
// horizontal/vertical lines (see issue 717)
// Note that performance is currently terrible, so some way to improve would
// be great.
//
// Parameters:
// selected - Container or <use> DOM element
function groupBBFix (selected) {
	if (svgedit.browser.supportsHVLineContainerBBox()) {
		try { return selected.getBBox(); } catch (e) {}
	}
	var ref = $.data(selected, 'ref');
	var matched = null;
	var ret, copy;

	if (ref) {
		copy = $(ref).children().clone().attr('visibility', 'hidden');
		$(svgroot_).append(copy);
		matched = copy.filter('line, path');
	} else {
		matched = $(selected).find('line, path');
	}

	var issue = false;
	if (matched.length) {
		matched.each(function () {
			var bb = this.getBBox();
			if (!bb.width || !bb.height) {
				issue = true;
			}
		});
		if (issue) {
			var elems = ref ? copy : $(selected).children();
			ret = getStrokedBBox(elems); // getStrokedBBox defined in svgcanvas
		} else {
			ret = selected.getBBox();
		}
	} else {
		ret = selected.getBBox();
	}
	if (ref) {
		copy.remove();
	}
	return ret;
}

// Function: svgedit.utilities.getBBox
// Get the given/selected element's bounding box object, convert it to be more
// usable when necessary
//
// Parameters:
// elem - Optional DOM element to get the BBox for
svgedit.utilities.getBBox = function (elem) {
	var selected = elem || editorContext_.geSelectedElements()[0];
	if (elem.nodeType !== 1) { return null; }
	var ret = null;
	var elname = selected.nodeName;

	switch (elname) {
	case 'text':
		if (selected.textContent === '') {
			selected.textContent = 'a'; // Some character needed for the selector to use.
			ret = selected.getBBox();
			selected.textContent = '';
		} else {
			if (selected.getBBox) { ret = selected.getBBox(); }
		}
		break;
	case 'path':
		if (!svgedit.browser.supportsPathBBox()) {
			ret = svgedit.utilities.getPathBBox(selected);
		} else {
			if (selected.getBBox) { ret = selected.getBBox(); }
		}
		break;
	case 'g':
	case 'a':
		ret = groupBBFix(selected);
		break;
	default:

		if (elname === 'use') {
			ret = groupBBFix(selected, true);
		}
		if (elname === 'use' || (elname === 'foreignObject' && svgedit.browser.isWebkit())) {
			if (!ret) { ret = selected.getBBox(); }
			// This is resolved in later versions of webkit, perhaps we should
			// have a featured detection for correct 'use' behavior?
			// ——————————
			if (!svgedit.browser.isWebkit()) {
				var bb = {};
				bb.width = ret.width;
				bb.height = ret.height;
				bb.x = ret.x + parseFloat(selected.getAttribute('x') || 0);
				bb.y = ret.y + parseFloat(selected.getAttribute('y') || 0);
				ret = bb;
			}
		} else if (~visElemsArr.indexOf(elname)) {
			if (selected) {
				try {
					ret = selected.getBBox();
				} catch (err) {
					// tspan (and textPath apparently) have no `getBBox` in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=937268
					// Re: Chrome returning bbox for containing text element, see: https://bugs.chromium.org/p/chromium/issues/detail?id=349835
					var extent = selected.getExtentOfChar(0); // pos+dimensions of the first glyph
					var width = selected.getComputedTextLength(); // width of the tspan
					ret = {
						x: extent.x,
						y: extent.y,
						width: width,
						height: extent.height
					};
				}
			} else {
				// Check if element is child of a foreignObject
				var fo = $(selected).closest('foreignObject');
				if (fo.length) {
					if (fo[0].getBBox) {
						ret = fo[0].getBBox();
					}
				}
			}
		}
	}
	if (ret) {
		ret = svgedit.utilities.bboxToObj(ret);
	}

	// get the bounding box from the DOM (which is in that element's coordinate system)
	return ret;
};

// Function: getPathDFromSegments
// Create a path 'd' attribute from path segments.
// Each segment is an array of the form: [singleChar, [x,y, x,y, ...]]
//
// Parameters:
// pathSegments - An array of path segments to be converted
//
// Returns:
// The converted path d attribute.
svgedit.utilities.getPathDFromSegments = function (pathSegments) {
	var d = '';

	$.each(pathSegments, function (j, seg) {
		var i;
		var pts = seg[1];
		d += seg[0];
		for (i = 0; i < pts.length; i += 2) {
			d += (pts[i] + ',' + pts[i + 1]) + ' ';
		}
	});

	return d;
};

// Function: getPathDFromElement
// Make a path 'd' attribute from a simple SVG element shape.
//
// Parameters:
// elem - The element to be converted
//
// Returns:
// The path d attribute or undefined if the element type is unknown.
svgedit.utilities.getPathDFromElement = function (elem) {
	// Possibly the cubed root of 6, but 1.81 works best
	var num = 1.81;
	var d, a, rx, ry;
	switch (elem.tagName) {
	case 'ellipse':
	case 'circle':
		a = $(elem).attr(['rx', 'ry', 'cx', 'cy']);
		var cx = a.cx, cy = a.cy;
		rx = a.rx;
		ry = a.ry;
		if (elem.tagName === 'circle') {
			rx = ry = $(elem).attr('r');
		}

		d = svgedit.utilities.getPathDFromSegments([
			['M', [(cx - rx), (cy)]],
			['C', [(cx - rx), (cy - ry / num), (cx - rx / num), (cy - ry), (cx), (cy - ry)]],
			['C', [(cx + rx / num), (cy - ry), (cx + rx), (cy - ry / num), (cx + rx), (cy)]],
			['C', [(cx + rx), (cy + ry / num), (cx + rx / num), (cy + ry), (cx), (cy + ry)]],
			['C', [(cx - rx / num), (cy + ry), (cx - rx), (cy + ry / num), (cx - rx), (cy)]],
			['Z', []]
		]);
		break;
	case 'path':
		d = elem.getAttribute('d');
		break;
	case 'line':
		a = $(elem).attr(['x1', 'y1', 'x2', 'y2']);
		d = 'M' + a.x1 + ',' + a.y1 + 'L' + a.x2 + ',' + a.y2;
		break;
	case 'polyline':
		d = 'M' + elem.getAttribute('points');
		break;
	case 'polygon':
		d = 'M' + elem.getAttribute('points') + ' Z';
		break;
	case 'rect':
		var r = $(elem).attr(['rx', 'ry']);
		rx = r.rx;
		ry = r.ry;
		var b = elem.getBBox();
		var x = b.x, y = b.y, w = b.width, h = b.height;
		num = 4 - num; // Why? Because!

		if (!rx && !ry) {
			// Regular rect
			d = svgedit.utilities.getPathDFromSegments([
				['M', [x, y]],
				['L', [x + w, y]],
				['L', [x + w, y + h]],
				['L', [x, y + h]],
				['L', [x, y]],
				['Z', []]
			]);
		} else {
			d = svgedit.utilities.getPathDFromSegments([
				['M', [x, y + ry]],
				['C', [x, y + ry / num, x + rx / num, y, x + rx, y]],
				['L', [x + w - rx, y]],
				['C', [x + w - rx / num, y, x + w, y + ry / num, x + w, y + ry]],
				['L', [x + w, y + h - ry]],
				['C', [x + w, y + h - ry / num, x + w - rx / num, y + h, x + w - rx, y + h]],
				['L', [x + rx, y + h]],
				['C', [x + rx / num, y + h, x, y + h - ry / num, x, y + h - ry]],
				['L', [x, y + ry]],
				['Z', []]
			]);
		}
		break;
	default:
		break;
	}

	return d;
};

// Function: getExtraAttributesForConvertToPath
// Get a set of attributes from an element that is useful for convertToPath.
//
// Parameters:
// elem - The element to be probed
//
// Returns:
// An object with attributes.
svgedit.utilities.getExtraAttributesForConvertToPath = function (elem) {
	var attrs = {};
	// TODO: make this list global so that we can properly maintain it
	// TODO: what about @transform, @clip-rule, @fill-rule, etc?
	$.each(['marker-start', 'marker-end', 'marker-mid', 'filter', 'clip-path'], function () {
		var a = elem.getAttribute(this);
		if (a) {
			attrs[this] = a;
		}
	});
	return attrs;
};

// Function: getBBoxOfElementAsPath
// Get the BBox of an element-as-path
//
// Parameters:
// elem - The DOM element to be probed
// addSvgElementFromJson - Function to add the path element to the current layer. See canvas.addSvgElementFromJson
// pathActions - If a transform exists, pathActions.resetOrientation() is used. See: canvas.pathActions.
//
// Returns:
// The resulting path's bounding box object.
svgedit.utilities.getBBoxOfElementAsPath = function (elem, addSvgElementFromJson, pathActions) {
	var path = addSvgElementFromJson({
		'element': 'path',
		'attr': svgedit.utilities.getExtraAttributesForConvertToPath(elem)
	});

	var eltrans = elem.getAttribute('transform');
	if (eltrans) {
		path.setAttribute('transform', eltrans);
	}

	var parent = elem.parentNode;
	if (elem.nextSibling) {
		parent.insertBefore(path, elem);
	} else {
		parent.appendChild(path);
	}

	var d = svgedit.utilities.getPathDFromElement(elem);
	if (d) path.setAttribute('d', d);
	else path.parentNode.removeChild(path);

	// Get the correct BBox of the new path, then discard it
	pathActions.resetOrientation(path);
	var bb = false;
	try {
		bb = path.getBBox();
	} catch (e) {
		// Firefox fails
	}
	path.parentNode.removeChild(path);
	return bb;
};

// Function: convertToPath
// Convert selected element to a path.
//
// Parameters:
// elem - The DOM element to be converted
// attrs - Apply attributes to new path. see canvas.convertToPath
// addSvgElementFromJson - Function to add the path element to the current layer. See canvas.addSvgElementFromJson
// pathActions - If a transform exists, pathActions.resetOrientation() is used. See: canvas.pathActions.
// clearSelection - see canvas.clearSelection
// addToSelection - see canvas.addToSelection
// history - see svgedit.history
// addCommandToHistory - see canvas.addCommandToHistory
//
// Returns:
// The converted path element or null if the DOM element was not recognized.
svgedit.utilities.convertToPath = function (elem, attrs, addSvgElementFromJson, pathActions, clearSelection, addToSelection, history, addCommandToHistory) {
	var batchCmd = new history.BatchCommand('Convert element to Path');

	// Any attribute on the element not covered by the passed-in attributes
	attrs = $.extend({}, attrs, svgedit.utilities.getExtraAttributesForConvertToPath(elem));

	var path = addSvgElementFromJson({
		'element': 'path',
		'attr': attrs
	});

	var eltrans = elem.getAttribute('transform');
	if (eltrans) {
		path.setAttribute('transform', eltrans);
	}

	var id = elem.id;
	var parent = elem.parentNode;
	if (elem.nextSibling) {
		parent.insertBefore(path, elem);
	} else {
		parent.appendChild(path);
	}

	var d = svgedit.utilities.getPathDFromElement(elem);
	if (d) {
		path.setAttribute('d', d);

		// Replace the current element with the converted one

		// Reorient if it has a matrix
		if (eltrans) {
			var tlist = svgedit.transformlist.getTransformList(path);
			if (svgedit.math.hasMatrixTransform(tlist)) {
				pathActions.resetOrientation(path);
			}
		}

		var nextSibling = elem.nextSibling;
		batchCmd.addSubCommand(new history.RemoveElementCommand(elem, nextSibling, parent));
		batchCmd.addSubCommand(new history.InsertElementCommand(path));

		clearSelection();
		elem.parentNode.removeChild(elem);
		path.setAttribute('id', id);
		path.removeAttribute('visibility');
		addToSelection([path], true);

		addCommandToHistory(batchCmd);

		return path;
	} else {
		// the elem.tagName was not recognized, so no "d" attribute. Remove it, so we've haven't changed anything.
		path.parentNode.removeChild(path);
		return null;
	}
};

// Function: bBoxCanBeOptimizedOverNativeGetBBox
// Can the bbox be optimized over the native getBBox? The optimized bbox is the same as the native getBBox when
// the rotation angle is a multiple of 90 degrees and there are no complex transforms.
// Getting an optimized bbox can be dramatically slower, so we want to make sure it's worth it.
//
// The best example for this is a circle rotate 45 degrees. The circle doesn't get wider or taller when rotated
// about it's center.
//
// The standard, unoptimized technique gets the native bbox of the circle, rotates the box 45 degrees, uses
// that width and height, and applies any transforms to get the final bbox. This means the calculated bbox
// is much wider than the original circle. If the angle had been 0, 90, 180, etc. both techniques render the
// same bbox.
//
// The optimization is not needed if the rotation is a multiple 90 degrees. The default technique is to call
// getBBox then apply the angle and any transforms.
//
// Parameters:
// angle - The rotation angle in degrees
// hasMatrixTransform - True if there is a matrix transform
//
// Returns:
// True if the bbox can be optimized.
function bBoxCanBeOptimizedOverNativeGetBBox (angle, hasMatrixTransform) {
	var angleModulo90 = angle % 90;
	var closeTo90 = angleModulo90 < -89.99 || angleModulo90 > 89.99;
	var closeTo0 = angleModulo90 > -0.001 && angleModulo90 < 0.001;
	return hasMatrixTransform || !(closeTo0 || closeTo90);
}

// Function: getBBoxWithTransform
// Get bounding box that includes any transforms.
//
// Parameters:
// elem - The DOM element to be converted
// addSvgElementFromJson - Function to add the path element to the current layer. See canvas.addSvgElementFromJson
// pathActions - If a transform exists, pathActions.resetOrientation() is used. See: canvas.pathActions.
//
// Returns:
// A single bounding box object
svgedit.utilities.getBBoxWithTransform = function (elem, addSvgElementFromJson, pathActions) {
	// TODO: Fix issue with rotated groups. Currently they work
	// fine in FF, but not in other browsers (same problem mentioned
	// in Issue 339 comment #2).

	var bb = svgedit.utilities.getBBox(elem);

	if (!bb) {
		return null;
	}

	var tlist = svgedit.transformlist.getTransformList(elem);
	var angle = svgedit.utilities.getRotationAngleFromTransformList(tlist);
	var hasMatrixTransform = svgedit.math.hasMatrixTransform(tlist);

	if (angle || hasMatrixTransform) {
		var goodBb = false;
		if (bBoxCanBeOptimizedOverNativeGetBBox(angle, hasMatrixTransform)) {
			// Get the BBox from the raw path for these elements
			// TODO: why ellipse and not circle
			var elemNames = ['ellipse', 'path', 'line', 'polyline', 'polygon'];
			if (elemNames.indexOf(elem.tagName) >= 0) {
				bb = goodBb = svgedit.utilities.getBBoxOfElementAsPath(elem, addSvgElementFromJson, pathActions);
			} else if (elem.tagName === 'rect') {
				// Look for radius
				var rx = elem.getAttribute('rx');
				var ry = elem.getAttribute('ry');
				if (rx || ry) {
					bb = goodBb = svgedit.utilities.getBBoxOfElementAsPath(elem, addSvgElementFromJson, pathActions);
				}
			}
		}

		if (!goodBb) {
			var matrix = svgedit.math.transformListToTransform(tlist).matrix;
			bb = svgedit.math.transformBox(bb.x, bb.y, bb.width, bb.height, matrix).aabox;

			// Old technique that was exceedingly slow with large documents.
			//
			// Accurate way to get BBox of rotated element in Firefox:
			// Put element in group and get its BBox
			//
			// Must use clone else FF freaks out
			// var clone = elem.cloneNode(true);
			// var g = document.createElementNS(NS.SVG, 'g');
			// var parent = elem.parentNode;
			// parent.appendChild(g);
			// g.appendChild(clone);
			// var bb2 = svgedit.utilities.bboxToObj(g.getBBox());
			// parent.removeChild(g);
		}
	}
	return bb;
};

// TODO: This is problematic with large stroke-width and, for example, a single horizontal line. The calculated BBox extends way beyond left and right sides.
function getStrokeOffsetForBBox (elem) {
	var sw = elem.getAttribute('stroke-width');
	return (!isNaN(sw) && elem.getAttribute('stroke') !== 'none') ? sw / 2 : 0;
}

// Function: getStrokedBBox
// Get the bounding box for one or more stroked and/or transformed elements
//
// Parameters:
// elems - Array with DOM elements to check
// addSvgElementFromJson - Function to add the path element to the current layer. See canvas.addSvgElementFromJson
// pathActions - If a transform exists, pathActions.resetOrientation() is used. See: canvas.pathActions.
//
// Returns:
// A single bounding box object
svgedit.utilities.getStrokedBBox = function (elems, addSvgElementFromJson, pathActions) {
	if (!elems || !elems.length) { return false; }

	var fullBb;
	$.each(elems, function () {
		if (fullBb) { return; }
		if (!this.parentNode) { return; }
		fullBb = svgedit.utilities.getBBoxWithTransform(this, addSvgElementFromJson, pathActions);
	});

	// This shouldn't ever happen...
	if (fullBb === undefined) { return null; }

	// fullBb doesn't include the stoke, so this does no good!
	// if (elems.length == 1) return fullBb;

	var maxX = fullBb.x + fullBb.width;
	var maxY = fullBb.y + fullBb.height;
	var minX = fullBb.x;
	var minY = fullBb.y;

	// If only one elem, don't call the potentially slow getBBoxWithTransform method again.
	if (elems.length === 1) {
		var offset = getStrokeOffsetForBBox(elems[0]);
		minX -= offset;
		minY -= offset;
		maxX += offset;
		maxY += offset;
	} else {
		$.each(elems, function (i, elem) {
			var curBb = svgedit.utilities.getBBoxWithTransform(elem, addSvgElementFromJson, pathActions);
			if (curBb) {
				var offset = getStrokeOffsetForBBox(elem);
				minX = Math.min(minX, curBb.x - offset);
				minY = Math.min(minY, curBb.y - offset);
				// TODO: The old code had this test for max, but not min. I suspect this test should be for both min and max
				if (elem.nodeType === 1) {
					maxX = Math.max(maxX, curBb.x + curBb.width + offset);
					maxY = Math.max(maxY, curBb.y + curBb.height + offset);
				}
			}
		});
	}

	fullBb.x = minX;
	fullBb.y = minY;
	fullBb.width = maxX - minX;
	fullBb.height = maxY - minY;
	return fullBb;
};

// Function: svgedit.utilities.getRotationAngleFromTransformList
// Get the rotation angle of the given transform list.
//
// Parameters:
// tlist - List of transforms
// toRad - Boolean that when true returns the value in radians rather than degrees
//
// Returns:
// Float with the angle in degrees or radians
svgedit.utilities.getRotationAngleFromTransformList = function (tlist, toRad) {
	if (!tlist) { return 0; } // <svg> elements have no tlist
	var N = tlist.numberOfItems;
	var i;
	for (i = 0; i < N; ++i) {
		var xform = tlist.getItem(i);
		if (xform.type === 4) {
			return toRad ? xform.angle * Math.PI / 180.0 : xform.angle;
		}
	}
	return 0.0;
};

// Function: svgedit.utilities.getRotationAngle
// Get the rotation angle of the given/selected DOM element
//
// Parameters:
// elem - Optional DOM element to get the angle for
// toRad - Boolean that when true returns the value in radians rather than degrees
//
// Returns:
// Float with the angle in degrees or radians
svgedit.utilities.getRotationAngle = function (elem, toRad) {
	var selected = elem || editorContext_.getSelectedElements()[0];
	// find the rotation transform (if any) and set it
	var tlist = svgedit.transformlist.getTransformList(selected);
	return svgedit.utilities.getRotationAngleFromTransformList(tlist, toRad);
};

// Function getRefElem
// Get the reference element associated with the given attribute value
//
// Parameters:
// attrVal - The attribute value as a string
svgedit.utilities.getRefElem = function (attrVal) {
	return svgedit.utilities.getElem(svgedit.utilities.getUrlFromAttr(attrVal).substr(1));
};

// Function: getElem
// Get a DOM element by ID within the SVG root element.
//
// Parameters:
// id - String with the element's new ID
if (svgedit.browser.supportsSelectors()) {
	svgedit.utilities.getElem = function (id) {
		// querySelector lookup
		return svgroot_.querySelector('#' + id);
	};
} else if (svgedit.browser.supportsXpath()) {
	svgedit.utilities.getElem = function (id) {
		// xpath lookup
		return domdoc_.evaluate(
			'svg:svg[@id="svgroot"]//svg:*[@id="' + id + '"]',
			domcontainer_,
			function () { return svgedit.NS.SVG; },
			9,
			null).singleNodeValue;
	};
} else {
	svgedit.utilities.getElem = function (id) {
		// jQuery lookup: twice as slow as xpath in FF
		return $(svgroot_).find('[id=' + id + ']')[0];
	};
}

// Function: assignAttributes
// Assigns multiple attributes to an element.
//
// Parameters:
// node - DOM element to apply new attribute values to
// attrs - Object with attribute keys/values
// suspendLength - Optional integer of milliseconds to suspend redraw
// unitCheck - Boolean to indicate the need to use svgedit.units.setUnitAttr
svgedit.utilities.assignAttributes = function (node, attrs, suspendLength, unitCheck) {
	var i;
	for (i in attrs) {
		var ns = (i.substr(0, 4) === 'xml:'
			? NS.XML
			: i.substr(0, 6) === 'xlink:' ? NS.XLINK : null);

		if (ns) {
			node.setAttributeNS(ns, i, attrs[i]);
		} else if (!unitCheck) {
			node.setAttribute(i, attrs[i]);
		} else {
			svgedit.units.setUnitAttr(node, i, attrs[i]);
		}
	}
};

// Function: cleanupElement
// Remove unneeded (default) attributes, makes resulting SVG smaller
//
// Parameters:
// element - DOM element to clean up
svgedit.utilities.cleanupElement = function (element) {
	var defaults = {
		'fill-opacity': 1,
		'stop-opacity': 1,
		'opacity': 1,
		'stroke': 'none',
		'stroke-dasharray': 'none',
		'stroke-linejoin': 'miter',
		'stroke-linecap': 'butt',
		'stroke-opacity': 1,
		'stroke-width': 1,
		'rx': 0,
		'ry': 0
	};

	if (element.nodeName === 'ellipse') {
		// Ellipse elements requires rx and ry attributes
		delete defaults.rx;
		delete defaults.ry;
	}

	var attr;
	for (attr in defaults) {
		var val = defaults[attr];
		if (element.getAttribute(attr) === String(val)) {
			element.removeAttribute(attr);
		}
	}
};

// Function: snapToGrid
// round value to for snapping
// NOTE: This function did not move to svgutils.js since it depends on curConfig.
svgedit.utilities.snapToGrid = function (value) {
	var stepSize = editorContext_.getSnappingStep();
	var unit = editorContext_.getBaseUnit();
	if (unit !== 'px') {
		stepSize *= svgedit.units.getTypeMap()[unit];
	}
	value = Math.round(value / stepSize) * stepSize;
	return value;
};

svgedit.utilities.preg_quote = function (str, delimiter) {
	// From: http://phpjs.org/functions
	return String(str).replace(new RegExp('[.\\\\+*?\\[\\^\\]$(){}=!<>|:\\' + (delimiter || '') + '-]', 'g'), '\\$&');
};

/**
* @param {string} globalCheck A global which can be used to determine if the script is already loaded
* @param {array} scripts An array of scripts to preload (in order)
* @param {function} cb The callback to execute upon load.
*/
svgedit.utilities.executeAfterLoads = function (globalCheck, scripts, cb) {
	return function () {
		var args = arguments;
		function endCallback () {
			cb.apply(null, args);
		}
		if (window[globalCheck]) {
			endCallback();
		} else {
			scripts.reduceRight(function (oldFunc, script) {
				return function () {
					$.getScript(script, oldFunc);
				};
			}, endCallback)();
		}
	};
};

svgedit.utilities.buildCanvgCallback = function (callCanvg) {
	return svgedit.utilities.executeAfterLoads('canvg', ['canvg/rgbcolor.js', 'canvg/canvg.js'], callCanvg);
};

svgedit.utilities.buildJSPDFCallback = function (callJSPDF) {
	return svgedit.utilities.executeAfterLoads('RGBColor', ['canvg/rgbcolor.js'], function () {
		var arr = [];
		if (!RGBColor || RGBColor.ok === undef) { // It's not our RGBColor, so we'll need to load it
			arr.push('canvg/rgbcolor.js');
		}
		svgedit.utilities.executeAfterLoads('jsPDF', arr.concat('jspdf/underscore-min.js', 'jspdf/jspdf.min.js', 'jspdf/jspdf.plugin.svgToPdf.js'), callJSPDF)();
	});
};

/**
 * Prevents default browser click behaviour on the given element
 * @param img - The DOM element to prevent the click on
 */
svgedit.utilities.preventClickDefault = function (img) {
	$(img).click(function (e) { e.preventDefault(); });
};

/**
 * Create a clone of an element, updating its ID and its children's IDs when needed
 * @param {Element} el - DOM element to clone
 * @param {function()} getNextId - function the get the next unique ID.
 * @returns {Element}
 */
svgedit.utilities.copyElem = function (el, getNextId) {
	// manually create a copy of the element
	var newEl = document.createElementNS(el.namespaceURI, el.nodeName);
	$.each(el.attributes, function (i, attr) {
		if (attr.localName !== '-moz-math-font-style') {
			newEl.setAttributeNS(attr.namespaceURI, attr.nodeName, attr.value);
		}
	});
	// set the copied element's new id
	newEl.removeAttribute('id');
	newEl.id = getNextId();

	// Opera's "d" value needs to be reset for Opera/Win/non-EN
	// Also needed for webkit (else does not keep curved segments on clone)
	if (svgedit.browser.isWebkit() && el.nodeName === 'path') {
		var fixedD = svgedit.utilities.convertPath(el);
		newEl.setAttribute('d', fixedD);
	}

	// now create copies of all children
	$.each(el.childNodes, function (i, child) {
		switch (child.nodeType) {
		case 1: // element node
			newEl.appendChild(svgedit.utilities.copyElem(child, getNextId));
			break;
		case 3: // text node
			newEl.textContent = child.nodeValue;
			break;
		default:
			break;
		}
	});

	if ($(el).data('gsvg')) {
		$(newEl).data('gsvg', newEl.firstChild);
	} else if ($(el).data('symbol')) {
		var ref = $(el).data('symbol');
		$(newEl).data('ref', ref).data('symbol', ref);
	} else if (newEl.tagName === 'image') {
		svgedit.utilities.preventClickDefault(newEl);
	}

	return newEl;
};

/**
 * TODO: refactor callers in convertPath to use getPathDFromSegments instead of this function.
 * Legacy code refactored from svgcanvas.pathActions.convertPath
 * @param letter - path segment command
 * @param {Array.<Array.<number>>} points - x,y points.
 * @param {Array.<Array.<number>>=} morePoints - x,y points
 * @param {Array.<number>=}lastPoint - x,y point
 * @returns {string}
 */
function pathDSegment (letter, points, morePoints, lastPoint) {
	$.each(points, function (i, pnt) {
		points[i] = svgedit.units.shortFloat(pnt);
	});
	var segment = letter + points.join(' ');
	if (morePoints) {
		segment += ' ' + morePoints.join(' ');
	}
	if (lastPoint) {
		segment += ' ' + svgedit.units.shortFloat(lastPoint);
	}
	return segment;
}

// this is how we map paths to our preferred relative segment types
var pathMap = [0, 'z', 'M', 'm', 'L', 'l', 'C', 'c', 'Q', 'q', 'A', 'a',
	'H', 'h', 'V', 'v', 'S', 's', 'T', 't'];

/**
 * TODO: move to pathActions.js when migrating rest of pathActions out of svgcanvas.js
 * Convert a path to one with only absolute or relative values
 * @param {Object} path - the path to convert
 * @param {boolean} toRel - true of convert to relative
 * @returns {string}
 */
svgedit.utilities.convertPath = function (path, toRel) {
	var i;
	var segList = path.pathSegList;
	var len = segList.numberOfItems;
	var curx = 0, cury = 0;
	var d = '';
	var lastM = null;

	for (i = 0; i < len; ++i) {
		var seg = segList.getItem(i);
		// if these properties are not in the segment, set them to zero
		var x = seg.x || 0,
			y = seg.y || 0,
			x1 = seg.x1 || 0,
			y1 = seg.y1 || 0,
			x2 = seg.x2 || 0,
			y2 = seg.y2 || 0;

		var type = seg.pathSegType;
		var letter = pathMap[type]['to' + (toRel ? 'Lower' : 'Upper') + 'Case']();

		switch (type) {
		case 1: // z,Z closepath (Z/z)
			d += 'z';
			if (lastM && !toRel) {
				curx = lastM[0];
				cury = lastM[1];
			}
			break;
		case 12: // absolute horizontal line (H)
			x -= curx;
			// Fallthrough
		case 13: // relative horizontal line (h)
			if (toRel) {
				curx += x;
				letter = 'l';
			} else {
				x += curx;
				curx = x;
				letter = 'L';
			}
			// Convert to "line" for easier editing
			d += pathDSegment(letter, [[x, cury]]);
			break;
		case 14: // absolute vertical line (V)
			y -= cury;
			// Fallthrough
		case 15: // relative vertical line (v)
			if (toRel) {
				cury += y;
				letter = 'l';
			} else {
				y += cury;
				cury = y;
				letter = 'L';
			}
			// Convert to "line" for easier editing
			d += pathDSegment(letter, [[curx, y]]);
			break;
		case 2: // absolute move (M)
		case 4: // absolute line (L)
		case 18: // absolute smooth quad (T)
			x -= curx;
			y -= cury;
			// Fallthrough
		case 5: // relative line (l)
		case 3: // relative move (m)
		case 19: // relative smooth quad (t)
			if (toRel) {
				curx += x;
				cury += y;
			} else {
				x += curx;
				y += cury;
				curx = x;
				cury = y;
			}
			if (type === 2 || type === 3) { lastM = [curx, cury]; }

			d += pathDSegment(letter, [[x, y]]);
			break;
		case 6: // absolute cubic (C)
			x -= curx; x1 -= curx; x2 -= curx;
			y -= cury; y1 -= cury; y2 -= cury;
			// Fallthrough
		case 7: // relative cubic (c)
			if (toRel) {
				curx += x;
				cury += y;
			} else {
				x += curx; x1 += curx; x2 += curx;
				y += cury; y1 += cury; y2 += cury;
				curx = x;
				cury = y;
			}
			d += pathDSegment(letter, [[x1, y1], [x2, y2], [x, y]]);
			break;
		case 8: // absolute quad (Q)
			x -= curx; x1 -= curx;
			y -= cury; y1 -= cury;
			// Fallthrough
		case 9: // relative quad (q)
			if (toRel) {
				curx += x;
				cury += y;
			} else {
				x += curx; x1 += curx;
				y += cury; y1 += cury;
				curx = x;
				cury = y;
			}
			d += pathDSegment(letter, [[x1, y1], [x, y]]);
			break;
		case 10: // absolute elliptical arc (A)
			x -= curx;
			y -= cury;
			// Fallthrough
		case 11: // relative elliptical arc (a)
			if (toRel) {
				curx += x;
				cury += y;
			} else {
				x += curx;
				y += cury;
				curx = x;
				cury = y;
			}
			d += pathDSegment(letter, [[seg.r1, seg.r2]], [
				seg.angle,
				(seg.largeArcFlag ? 1 : 0),
				(seg.sweepFlag ? 1 : 0)
			], [x, y]);
			break;
		case 16: // absolute smooth cubic (S)
			x -= curx; x2 -= curx;
			y -= cury; y2 -= cury;
			// Fallthrough
		case 17: // relative smooth cubic (s)
			if (toRel) {
				curx += x;
				cury += y;
			} else {
				x += curx; x2 += curx;
				y += cury; y2 += cury;
				curx = x;
				cury = y;
			}
			d += pathDSegment(letter, [[x2, y2], [x, y]]);
			break;
		} // switch on path segment type
	} // for each segment
	return d;
};
}());