instiki/public/svg-edit/editor/svgutils.js
2011-02-03 11:13:18 -06:00

479 lines
13 KiB
JavaScript

/**
* Package: svgedit.utilities
*
* Licensed under the Apache License, Version 2
*
* Copyright(c) 2010 Alexis Deveria
* Copyright(c) 2010 Jeff Schiller
*/
// Dependencies:
// 1) jQuery
// 2) browser.js: only for getBBox()
// 3) svgtransformlist.js: only for getRotationAngle()
var svgedit = svgedit || {};
(function() {
if (!svgedit.utilities) {
svgedit.utilities = {};
}
// Constants
// String used to encode base64.
var KEYSTR = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
var SVGNS = 'http://www.w3.org/2000/svg';
var XLINKNS = 'http://www.w3.org/1999/xlink';
// 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 visElems_arr = visElems.split(',');
//var hidElems = 'clipPath,defs,desc,feGaussianBlur,filter,linearGradient,marker,mask,metadata,pattern,radialGradient,stop,switch,symbol,title,textPath';
var editorContext_ = null;
svgedit.utilities.init = function(editorContext) {
editorContext_ = editorContext;
};
// 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) {
return $('<p/>').text(str).html();
};
// 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 = new Array( 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 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 unescape(output);
};
// Currently not being used, so commented out for now
// based on http://phpjs.org/functions/utf8_encode:577
// codedread:does not seem to work with webkit-based browsers on OSX
// "encodeUTF8": function(input) {
// //return unescape(encodeURIComponent(input)); //may or may not work
// var output = '';
// for (var n = 0; n < input.length; n++){
// var c = input.charCodeAt(n);
// if (c < 128) {
// output += input[n];
// }
// else if (c > 127) {
// if (c < 2048){
// output += String.fromCharCode((c >> 6) | 192);
// }
// else {
// output += String.fromCharCode((c >> 12) | 224) + String.fromCharCode((c >> 6) & 63 | 128);
// }
// output += String.fromCharCode((c & 63) | 128);
// }
// }
// return output;
// },
// Function: svgedit.utilities.convertToXMLReferences
// Converts a string to use XML references
svgedit.utilities.convertToXMLReferences = function(input) {
var output = '';
for (var 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;
try{
var 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(e){ 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')
else if (attrVal.indexOf("url('") === 0) {
return attrVal.substring(5,attrVal.indexOf("'",6));
}
else 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(XLINKNS, "href");
}
// Function: svgedit.utilities.setHref
// Sets the given element's xlink:href value
svgedit.utilities.setHref = function(elem, val) {
elem.setAttributeNS(XLINKNS, "xlink:href", val);
}
// Function: findDefs
// Parameters:
// svgElement - The <svg> element.
//
// Returns:
// The document's <defs> element, create it first if necessary
svgedit.utilities.findDefs = function(svgElement) {
var svgElement = editorContext_.getSVGContent().documentElement;
var defs = svgElement.getElementsByTagNameNS(SVGNS, "defs");
if (defs.length > 0) {
defs = defs[0];
}
else {
// first child is a comment, so call nextSibling
defs = svgElement.insertBefore( svgElement.ownerDocument.createElementNS(SVGNS, "defs" ), svgElement.firstChild.nextSibling);
}
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];
for(var i=0; i < tot; i++) {
var seg = seglist.getItem(i);
if(!seg.x) 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];
for(var 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(0 < t && 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(0 < t1 && t1 < 1) bounds[j].push(calc(t1));
var t2 = (-b - Math.sqrt(b2ac))/(2 * a);
if(0 < t2 && 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: 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;
if(elname === 'text' && selected.textContent === '') {
selected.textContent = 'a'; // Some character needed for the selector to use.
ret = selected.getBBox();
selected.textContent = '';
} else if(elname === 'path' && !svgedit.browser.supportsPathBBox()) {
ret = svgedit.utilities.getPathBBox(selected);
} else if(elname === 'use' && !svgedit.browser.isWebkit() || elname === 'foreignObject') {
ret = selected.getBBox();
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(~visElems_arr.indexOf(elname)) {
try { ret = selected.getBBox();}
catch(e) {
// Check if element is child of a foreignObject
var fo = $(selected).closest("foreignObject");
if(fo.length) {
try {
ret = fo[0].getBBox();
} catch(e) {
ret = null;
}
} else {
ret = null;
}
}
}
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: svgedit.utilities.getRotationAngle
// Get the rotation angle of the given/selected DOM element
//
// Parameters:
// elem - Optional DOM element to get the angle for
// to_rad - 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, to_rad) {
var selected = elem || editorContext_.getSelectedElements()[0];
// find the rotation transform (if any) and set it
var tlist = svgedit.transformlist.getTransformList(selected);
if(!tlist) return 0; // <svg> elements have no tlist
var N = tlist.numberOfItems;
for (var i = 0; i < N; ++i) {
var xform = tlist.getItem(i);
if (xform.type == 4) {
return to_rad ? xform.angle * Math.PI / 180.0 : xform.angle;
}
}
return 0.0;
};
})();