Commit b8366108 authored by Mikael Salson's avatar Mikael Salson Committed by Mathieu Giraud

js/lib/svgExport.js: Export SVG to PNG

From http://bl.ocks.org/Rokotyan/0556f8facbaf344507cdc45dc3622177
See #3240.
parent dd256dd8
/*
This code is coming from
http://bl.ocks.org/Rokotyan/0556f8facbaf344507cdc45dc3622177 released under
the MIT license.
*/
function getSVGString( svgNode ) {
svgNode.setAttribute('xlink', 'http://www.w3.org/1999/xlink');
var cssStyleText = getCSSStyles( svgNode );
appendCSS( cssStyleText, svgNode );
var serializer = new XMLSerializer();
var svgString = serializer.serializeToString(svgNode);
svgString = svgString.replace(/(\w+)?:?xlink=/g, 'xmlns:xlink='); // Fix root xlink without namespace
svgString = svgString.replace(/NS\d+:href/g, 'xlink:href'); // Safari NS namespace fix
return svgString;
function getCSSStyles( parentElement ) {
var selectorTextArr = [];
// Add Parent element Id and Classes to the list
selectorTextArr.push( '#'+parentElement.id );
for (var c = 0; c < parentElement.classList.length; c++)
if ( !contains('.'+parentElement.classList[c], selectorTextArr) )
selectorTextArr.push( '.'+parentElement.classList[c] );
// Add Children element Ids and Classes to the list
var nodes = parentElement.getElementsByTagName("*");
for (var i = 0; i < nodes.length; i++) {
var id = nodes[i].id;
if ( !contains('#'+id, selectorTextArr) )
selectorTextArr.push( '#'+id );
var classes = nodes[i].classList;
for (var c = 0; c < classes.length; c++)
if ( !contains('.'+classes[c], selectorTextArr) )
selectorTextArr.push( '.'+classes[c] );
}
// Extract CSS Rules
var extractedCSSText = "";
for (var i = 0; i < document.styleSheets.length; i++) {
var s = document.styleSheets[i];
try {
if(!s.cssRules) continue;
} catch( e ) {
if(e.name !== 'SecurityError') throw e; // for Firefox
continue;
}
var cssRules = s.cssRules;
for (var r = 0; r < cssRules.length; r++) {
if ( contains( cssRules[r].selectorText, selectorTextArr ) )
extractedCSSText += cssRules[r].cssText;
}
}
return extractedCSSText;
function contains(str,arr) {
return arr.indexOf( str ) === -1 ? false : true;
}
}
function appendCSS( cssText, element ) {
var styleElement = document.createElement("style");
styleElement.setAttribute("type","text/css");
styleElement.innerHTML = cssText;
var refNode = element.hasChildNodes() ? element.children[0] : null;
element.insertBefore( styleElement, refNode );
}
}
function svgString2Image( svgString, width, height, format, callback ) {
var format = format ? format : 'png';
var imgsrc = 'data:image/svg+xml;base64,'+ btoa( unescape( encodeURIComponent( svgString ) ) ); // Convert SVG string to data URL
var canvas = document.createElement("canvas");
var context = canvas.getContext("2d");
canvas.width = width;
canvas.height = height;
var image = new Image();
image.onload = function() {
context.clearRect ( 0, 0, width, height );
context.drawImage(image, 0, 0, width, height);
canvas.toBlob( function(blob) {
var filesize = Math.round( blob.length/1024 ) + ' KB';
if ( callback ) callback( blob, filesize );
});
};
image.src = imgsrc;
}
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