sverweij/mscgen_js

var svgutensils = require('mscgenjs/dist/cjs/render/graphics/svgutensils')

var MAX_SIGNED_SHORT = 32767

function geckoRelativeSizeWorkaround (pString, pViewBox) {
  /* the ugly replace is to be sure gecko
  * actualy renders a picture when using the
  * 'autosize' feature. Not necessary in webkit &
  *  blink.
  *  Depends on the assumption 'autoscale' is
  *  implemented with 100%
  */
  if (!!pViewBox && !!pViewBox.baseVal) {
    return pString
      .replace(
        'width="100%"',
        'width="' + pViewBox.baseVal.width + '"'
      )
      .replace(
        'height="100%"',
        'height="' + pViewBox.baseVal.height + '"'
      )
  }
  return pString
}
module.exports = {
  toRasterURI: function (pDocument, pSVGParent, pType, pCallback) {
    var lImg = pDocument.createElement('img')

    lImg.src = 'data:image/svg+xml;charset=utf-8,' +
      encodeURIComponent(
        '<!DOCTYPE svg [<!ENTITY nbsp "&#160;">]>'.concat(
          geckoRelativeSizeWorkaround(
            svgutensils.webkitNamespaceBugWorkaround(
              pSVGParent.innerHTML
            ),
            pSVGParent.firstElementChild.viewBox
          )
        )
      )
    lImg.addEventListener('load', function (pEvent) {
      var lCanvas = pDocument.createElement('canvas')
      var lCanvasContext = lCanvas.getContext('2d')
      var lImage = pEvent.target

      /*
     * When the passed image is too big for the browser to handle
     * return an error string
     *
     * See https://github.com/sverweij/mscgen_js/issues/248 for
     * an overview of the practical limits in various browsers and
     * pointers for further research.
     */
      if (lImage.width > MAX_SIGNED_SHORT || lImage.height > MAX_SIGNED_SHORT) {
        pCallback(null, 'image-too-big')
      } else {
        lCanvas.width = lImage.width
        lCanvas.height = lImage.height

        lCanvasContext.drawImage(lImage, 0, 0)
        pCallback(lCanvas.toDataURL(pType, 0.8))
      }
    }, { capture: false, passive: true })
  }
}
/*
 This file is part of mscgen_js.

 mscgen_js is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 mscgen_js is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with mscgen_js.  If not, see <http://www.gnu.org/licenses/>.
 */