modules/svg.js

/* global jsPDF, canvg */
/** @license
 * Copyright (c) 2012 Willow Systems Corporation, willow-systems.com
 * 
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * ====================================================================
 */

/**
* jsPDF SVG plugin
*
* @name svg
* @module
*/
(function (jsPDFAPI) {
    'use strict'

    /**
    * Parses SVG XML and converts only some of the SVG elements into
    * PDF elements.
    *
    * Supports:
    * paths
    * 
    * @name addSvg
    * @public
	* @function 
    * @param {string} SVG-Data as Text
    * @param {number} x Coordinate (in units declared at inception of PDF document) against left edge of the page
    * @param {number} y Coordinate (in units declared at inception of PDF document) against upper edge of the page
    * @param {number} width of SVG (in units declared at inception of PDF document)
    * @param {number} height of SVG (in units declared at inception of PDF document)
    * @returns {Object} jsPDF-instance
	*/
    jsPDFAPI.addSvg = function (svgtext, x, y, w, h) {
        // 'this' is _jsPDF object returned when jsPDF is inited (new jsPDF())

        if (x === undefined || y === undefined) {
            throw new Error("addSVG needs values for 'x' and 'y'");
        }

        function InjectCSS(cssbody, document) {
            var styletag = document.createElement('style');
            styletag.type = 'text/css';
            if (styletag.styleSheet) {
                // ie
                styletag.styleSheet.cssText = cssbody;
            } else {
                // others
                styletag.appendChild(document.createTextNode(cssbody));
            }
            document.getElementsByTagName("head")[0].appendChild(styletag);
        }

        function createWorkerNode(document) {

            var frameID = 'childframe' // Date.now().toString() + '_' + (Math.random() * 100).toString()
                , frame = document.createElement('iframe');

            InjectCSS(
                '.jsPDF_sillysvg_iframe {display:none;position:absolute;}'
                , document
            );

            frame.name = frameID;
            frame.setAttribute("width", 0);
            frame.setAttribute("height", 0);
            frame.setAttribute("frameborder", "0");
            frame.setAttribute("scrolling", "no");
            frame.setAttribute("seamless", "seamless");
            frame.setAttribute("class", "jsPDF_sillysvg_iframe");

            document.body.appendChild(frame);

            return frame;
        }

        function attachSVGToWorkerNode(svgtext, frame) {
            var framedoc = (frame.contentWindow || frame.contentDocument).document;
            framedoc.write(svgtext);
            framedoc.close();
            return framedoc.getElementsByTagName('svg')[0];
        }

        function convertPathToPDFLinesArgs(path) {
            'use strict'
            // we will use 'lines' method call. it needs:
            // - starting coordinate pair
            // - array of arrays of vector shifts (2-len for line, 6 len for bezier)
            // - scale array [horizontal, vertical] ratios
            // - style (stroke, fill, both)

            var x = parseFloat(path[1])
                , y = parseFloat(path[2])
                , vectors = []
                , position = 3
                , len = path.length;

            while (position < len) {
                if (path[position] === 'c') {
                    vectors.push([
                        parseFloat(path[position + 1])
                        , parseFloat(path[position + 2])
                        , parseFloat(path[position + 3])
                        , parseFloat(path[position + 4])
                        , parseFloat(path[position + 5])
                        , parseFloat(path[position + 6])
                    ]);
                    position += 7;
                } else if (path[position] === 'l') {
                    vectors.push([
                        parseFloat(path[position + 1])
                        , parseFloat(path[position + 2])
                    ]);
                    position += 3;
                } else {
                    position += 1;
                }
            }
            return [x, y, vectors];
        }

        var workernode = createWorkerNode(document)
            , svgnode = attachSVGToWorkerNode(svgtext, workernode)
            , scale = [1, 1]
            , svgw = parseFloat(svgnode.getAttribute('width'))
            , svgh = parseFloat(svgnode.getAttribute('height'));

        if (svgw && svgh) {
            // setting both w and h makes image stretch to size.
            // this may distort the image, but fits your demanded size
            if (w && h) {
                scale = [w / svgw, h / svgh];
            }
            // if only one is set, that value is set as max and SVG
            // is scaled proportionately.
            else if (w) {
                scale = [w / svgw, w / svgw];
            } else if (h) {
                scale = [h / svgh, h / svgh];
            }
        }

        var i, l, tmp
            , linesargs
            , items = svgnode.childNodes;
        for (i = 0, l = items.length; i < l; i++) {
            tmp = items[i];
            if (tmp.tagName && tmp.tagName.toUpperCase() === 'PATH') {
                linesargs = convertPathToPDFLinesArgs(tmp.getAttribute("d").split(' '));
                // path start x coordinate
                linesargs[0] = linesargs[0] * scale[0] + x; // where x is upper left X of image
                // path start y coordinate
                linesargs[1] = linesargs[1] * scale[1] + y; // where y is upper left Y of image
                // the rest of lines are vectors. these will adjust with scale value auto.
                this.lines.call(
                    this
                    , linesargs[2] // lines
                    , linesargs[0] // starting x
                    , linesargs[1] // starting y
                    , scale
                );
            }
        }

        // clean up
        // workernode.parentNode.removeChild(workernode)

        return this;
    };

    //fallback
    jsPDFAPI.addSVG = jsPDFAPI.addSvg;

    /**
    * Parses SVG XML and saves it as image into the PDF.
    *
    * Depends on canvas-element and canvg
    *
    * @name addSvgAsImage
    * @public
    * @function
    * @param {string} SVG-Data as Text
    * @param {number} x Coordinate (in units declared at inception of PDF document) against left edge of the page
    * @param {number} y Coordinate (in units declared at inception of PDF document) against upper edge of the page
    * @param {number} width of SVG-Image (in units declared at inception of PDF document)
    * @param {number} height of SVG-Image (in units declared at inception of PDF document)
    * @param {string} alias of SVG-Image (if used multiple times)
    * @param {string} compression of the generated JPEG, can have the values 'NONE', 'FAST', 'MEDIUM' and 'SLOW'
    * @param {number} rotation of the image in degrees (0-359)
    * 
    * @returns jsPDF jsPDF-instance
    */
    jsPDFAPI.addSvgAsImage = function (svg, x, y, w, h, alias, compression, rotation) {


        if (isNaN(x) || isNaN(y)) {
            console.error('jsPDF.addSvgAsImage: Invalid coordinates', arguments);
            throw new Error('Invalid coordinates passed to jsPDF.addSvgAsImage');
        }

        if (isNaN(w) || isNaN(h)) {
            console.error('jsPDF.addSvgAsImage: Invalid measurements', arguments);
            throw new Error('Invalid measurements (width and/or height) passed to jsPDF.addSvgAsImage');
        }


        var canvas = document.createElement('canvas');
        canvas.width = w;
        canvas.height = h;
        var ctx = canvas.getContext('2d');
        ctx.fillStyle = '#fff';  /// set white fill style
        ctx.fillRect(0, 0, canvas.width, canvas.height);

        //load a svg snippet in the canvas with id = 'drawingArea'
        canvg(canvas, svg, {
            ignoreMouse: true,
            ignoreAnimation: true,
            ignoreDimensions: true,
            ignoreClear: true
        });

        this.addImage(canvas.toDataURL("image/jpeg", 1.0), x, y, w, h, compression, rotation);
        return this;
    };

})(jsPDF.API);