svgicons2svgfont/src/index.js

/* eslint-disable complexity,prefer-reflect,max-len,newline-after-var */
/* eslint no-multi-str:0 */

'use strict';

const { ucs2 } = require('punycode');
const { Transform } = require('stream');
const Sax = require('sax');
const { SVGPathData } = require('svg-pathdata');
const svgShapesToPath = require('./svgshapes2svgpath');
const { Matrix } = require('transformation-matrix-js');

require('string.prototype.codepointat');

// Transform helpers (will move elsewhere later)
function parseTransforms(value) {
  return value
    .match(/(rotate|translate|scale|skewX|skewY|matrix)\s*\(([^)]*)\)\s*/g)
    .map(transform => transform.match(/[\w.-]+/g));
}
function matrixFromTransformAttribute(transformAttributeString) {
  const transformations = {
    matrix: (result, ...args) => result.transform(...args),
    translate: (result, x, y = 0) => result.translate(x, y),
    scale: (result, x, y = x) => result.scale(x, y),
    rotate: (result, a, x = 0, y = 0) => {
      if (0 === x && 0 === y) {
        result.rotateDeg(a);
      } else {
        result
          .translate(x, y)
          .rotateDeg(a)
          .translate(-x, -y);
      }
    },
    skewX: (result, a) => result.skewX(a * Math.PI / 180),
    skewY: (result, a) => result.skewY(a * Math.PI / 180),
  };

  const result = new Matrix();
  for (const transform of parseTransforms(transformAttributeString)) {
    transformations[transform[0]](
      result,
      ...transform.slice(1).map(parseFloat)
    );
  }
  return result;
}

// Rendering
function tagShouldRender(curTag, parents) {
  let values;

  return !parents.some(tag => {
    if (
      'undefined' !== typeof tag.attributes.display &&
      'none' === tag.attributes.display.toLowerCase()
    ) {
      return true;
    }
    if (
      'undefined' !== typeof tag.attributes.width &&
      0 === parseFloat(tag.attributes.width)
    ) {
      return true;
    }
    if (
      'undefined' !== typeof tag.attributes.height &&
      0 === parseFloat(tag.attributes.height)
    ) {
      return true;
    }
    if ('undefined' !== typeof tag.attributes.viewBox) {
      values = tag.attributes.viewBox.split(/\s*,*\s|\s,*\s*|,/);
      if (0 === parseFloat(values[2]) || 0 === parseFloat(values[3])) {
        return true;
      }
    }
    return false;
  });
}

// According to the document (http://www.w3.org/TR/SVG/painting.html#FillProperties)
// fill <paint> none|currentColor|inherit|<color>
//     [<icccolor>]|<funciri> (not support yet)
function getTagColor(currTag, parents) {
  const defaultColor = 'black';
  const fillVal = currTag.attributes.fill;
  let color;
  const parentsLength = parents.length;

  if ('none' === fillVal) {
    return color;
  }
  if ('currentColor' === fillVal) {
    return defaultColor;
  }
  if ('inherit' === fillVal) {
    if (0 === parentsLength) {
      return defaultColor;
    }
    return getTagColor(
      parents[parentsLength - 1],
      parents.slice(0, parentsLength - 1)
    );
    // this might be null.
    // For example: <svg ><path fill="inherit" /> </svg>
    // in this case getTagColor should return null
    // recursive call, the bottom element should be svg,
    // and svg didn't fill color, so just return null
  }

  return fillVal;
}

class SVGIcons2SVGFontStream extends Transform {
  constructor(options) {
    super({ objectMode: true });

    // Setting objectMode separately
    this._writableState.objectMode = true;
    this._readableState.objectMode = false;

    this.glyphs = [];

    this._options = options || {};
    this._options.fontName = this._options.fontName || 'iconfont';
    this._options.fontId = this._options.fontId || this._options.fontName;
    this._options.fixedWidth = this._options.fixedWidth || false;
    this._options.descent = this._options.descent || 0;
    this._options.round = this._options.round || 10e12;
    this._options.metadata = this._options.metadata || '';

    this.log = this._options.log || console.log.bind(console); // eslint-disable-line
  }

  _transform(svgIconStream, _unused, svgIconStreamCallback) {
    // Parsing each icons asynchronously
    const saxStream = Sax.createStream(true);
    const parents = [];
    const transformStack = [new Matrix()];
    function applyTransform(d) {
      return new SVGPathData(d).matrix(
        ...transformStack[transformStack.length - 1].toArray()
      );
    }
    const glyph = svgIconStream.metadata || {};

    // init width and height os they aren't undefined if <svg> isn't renderable
    glyph.width = 0;
    glyph.height = 1;

    glyph.paths = [];
    this.glyphs.push(glyph);

    if ('string' !== typeof glyph.name) {
      this.emit(
        'error',
        new Error(
          `Please provide a name for the glyph at index ${this.glyphs.length -
            1}`
        )
      );
    }
    if (
      this.glyphs.some(
        anotherGlyph =>
          anotherGlyph !== glyph && anotherGlyph.name === glyph.name
      )
    ) {
      this.emit(
        'error',
        new Error(`The glyph name "${glyph.name}" must be unique.`)
      );
    }
    if (
      glyph.unicode &&
      glyph.unicode instanceof Array &&
      glyph.unicode.length
    ) {
      if (
        glyph.unicode.some((unicodeA, i) =>
          glyph.unicode.some((unicodeB, j) => i !== j && unicodeA === unicodeB)
        )
      ) {
        this.emit(
          'error',
          new Error(
            `Given codepoints for the glyph "${glyph.name}" contain duplicates.`
          )
        );
      }
    } else if ('string' !== typeof glyph.unicode) {
      this.emit(
        'error',
        new Error(`Please provide a codepoint for the glyph "${glyph.name}"`)
      );
    }

    if (
      this.glyphs.some(
        anotherGlyph =>
          anotherGlyph !== glyph && anotherGlyph.unicode === glyph.unicode
      )
    ) {
      this.emit(
        'error',
        new Error(
          `The glyph "${
            glyph.name
          }" codepoint seems to be used already elsewhere.`
        )
      );
    }

    saxStream.on('opentag', tag => {
      let values;
      let color;

      parents.push(tag);
      try {
        const currentTransform = transformStack[transformStack.length - 1];

        if ('undefined' !== typeof tag.attributes.transform) {
          const transform = matrixFromTransformAttribute(
            tag.attributes.transform
          );
          transformStack.push(currentTransform.clone().multiply(transform));
        } else {
          transformStack.push(currentTransform);
        }
        // Checking if any parent rendering is disabled and exit if so
        if (!tagShouldRender(tag, parents)) {
          return;
        }

        // Save the view size
        if ('svg' === tag.name) {
          if ('viewBox' in tag.attributes) {
            values = tag.attributes.viewBox.split(/\s*,*\s|\s,*\s*|,/);
            const dX = parseFloat(values[0]);
            const dY = parseFloat(values[1]);
            const width = parseFloat(values[2]);
            const height = parseFloat(values[3]);

            // use the viewBox width/height if not specified explictly
            glyph.width =
              'width' in tag.attributes
                ? parseFloat(tag.attributes.width)
                : width;
            glyph.height =
              'height' in tag.attributes
                ? parseFloat(tag.attributes.height)
                : height;

            transformStack[transformStack.length - 1]
              .translate(-dX, -dY)
              .scale(glyph.width / width, glyph.height / height);
          } else {
            if ('width' in tag.attributes) {
              glyph.width = parseFloat(tag.attributes.width);
            } else {
              this.log(
                `Glyph "${
                  glyph.name
                }" has no width attribute, defaulting to 150.`
              );
              glyph.width = 150;
            }
            if ('height' in tag.attributes) {
              glyph.height = parseFloat(tag.attributes.height);
            } else {
              this.log(
                `Glyph "${
                  glyph.name
                }" has no height attribute, defaulting to 150.`
              );
              glyph.height = 150;
            }
          }
        } else if ('clipPath' === tag.name) {
          // Clipping path unsupported
          this.log(
            `Found a clipPath element in the icon "${
              glyph.name
            }" the result may be different than expected.`
          );
        } else if ('rect' === tag.name && 'none' !== tag.attributes.fill) {
          glyph.paths.push(
            applyTransform(svgShapesToPath.rectToPath(tag.attributes))
          );
        } else if ('line' === tag.name && 'none' !== tag.attributes.fill) {
          this.log(
            `Found a line element in the icon "${
              glyph.name
            }" the result could be different than expected.`
          );
          glyph.paths.push(
            applyTransform(svgShapesToPath.lineToPath(tag.attributes))
          );
        } else if ('polyline' === tag.name && 'none' !== tag.attributes.fill) {
          this.log(
            `Found a polyline element in the icon "${
              glyph.name
            }" the result could be different than expected.`
          );
          glyph.paths.push(
            applyTransform(svgShapesToPath.polylineToPath(tag.attributes))
          );
        } else if ('polygon' === tag.name && 'none' !== tag.attributes.fill) {
          glyph.paths.push(
            applyTransform(svgShapesToPath.polygonToPath(tag.attributes))
          );
        } else if (
          ['circle', 'ellipse'].includes(tag.name) &&
          'none' !== tag.attributes.fill
        ) {
          glyph.paths.push(
            applyTransform(svgShapesToPath.circleToPath(tag.attributes))
          );
        } else if (
          'path' === tag.name &&
          tag.attributes.d &&
          'none' !== tag.attributes.fill
        ) {
          glyph.paths.push(applyTransform(tag.attributes.d));
        }

        // According to http://www.w3.org/TR/SVG/painting.html#SpecifyingPaint
        // Map attribute fill to color property
        if ('none' !== tag.attributes.fill) {
          color = getTagColor(tag, parents);
          if ('undefined' !== typeof color) {
            glyph.color = color;
          }
        }
      } catch (err) {
        this.emit(
          'error',
          new Error(
            `Got an error parsing the glyph "${glyph.name}": ${err.message}.`
          )
        );
      }
    });

    saxStream.on('error', err => {
      this.emit('error', err);
    });

    saxStream.on('closetag', () => {
      transformStack.pop();
      parents.pop();
    });

    saxStream.on('end', () => {
      svgIconStreamCallback();
    });

    svgIconStream.pipe(saxStream);
  }

  _flush(svgFontFlushCallback) {
    const maxGlyphHeight = this.glyphs.reduce(
      (curMax, glyph) => Math.max(curMax, glyph.height),
      0
    );
    const maxGlyphWidth = this.glyphs.reduce(
      (curMax, glyph) => Math.max(curMax, glyph.width),
      0
    );
    const fontHeight = this._options.fontHeight || maxGlyphHeight;
    let fontWidth = maxGlyphWidth;
    if (this._options.normalize) {
      fontWidth = this.glyphs.reduce(
        (curMax, glyph) =>
          Math.max(curMax, fontHeight / glyph.height * glyph.width),
        0
      );
    } else if (this._options.fontHeight) {
      // even if normalize is off, we need to scale the fontWidth if we have a custom fontHeight
      fontWidth *= fontHeight / maxGlyphHeight;
    }

    this._options.ascent =
      'undefined' !== typeof this._options.ascent
        ? this._options.ascent
        : fontHeight - this._options.descent;

    if (
      !this._options.normalize &&
      fontHeight >
        (1 < this.glyphs.length
          ? this.glyphs.reduce(
              (curMin, glyph) => Math.min(curMin, glyph.height),
              Infinity
            )
          : this.glyphs[0].height)
    ) {
      this.log(
        'The provided icons do not have the same heights. This could lead' +
          ' to unexpected results. Using the normalize option may help.'
      );
    }
    if (1000 > fontHeight) {
      this.log(
        'A fontHeight of at least than 1000 is recommended, otherwise ' +
          'further steps (rounding in svg2ttf) could lead to ugly results.' +
          ' Use the fontHeight option to scale icons.'
      );
    }

    // Output the SVG file
    // (find a SAX parser that allows modifying SVG on the fly)
    /* eslint-disable prefer-template */
    this.push(
      '<?xml version="1.0" standalone="no"?>\n' +
        '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd" >\n' +
        '<svg xmlns="http://www.w3.org/2000/svg">\n' +
        (this._options.metadata
          ? '<metadata>' + this._options.metadata + '</metadata>\n'
          : '') +
        '<defs>\n' +
        '  <font id="' +
        this._options.fontId +
        '" horiz-adv-x="' +
        fontWidth +
        '">\n' +
        '    <font-face font-family="' +
        this._options.fontName +
        '"\n' +
        '      units-per-em="' +
        fontHeight +
        '" ascent="' +
        this._options.ascent +
        '"\n' +
        '      descent="' +
        this._options.descent +
        '"' +
        (this._options.fontWeight
          ? '\n      font-weight="' + this._options.fontWeight + '"'
          : '') +
        (this._options.fontStyle
          ? '\n      font-style="' + this._options.fontStyle + '"'
          : '') +
        ' />\n' +
        '    <missing-glyph horiz-adv-x="0" />\n'
    );

    this.glyphs.forEach(glyph => {
      const ratio = this._options.normalize
        ? fontHeight / glyph.height
        : fontHeight / maxGlyphHeight;
      if (!isFinite(ratio)) throw new Error('foo');
      glyph.width *= ratio;
      glyph.height *= ratio;
      const glyphPath = new SVGPathData('');

      if (this._options.fixedWidth) {
        glyph.width = fontWidth;
      }
      const yOffset = glyph.height - this._options.descent;
      const glyphPathTransform = new Matrix().transform(
        1,
        0,
        0,
        -1,
        0,
        yOffset
      ); // ySymmetry
      if (1 !== ratio) {
        glyphPathTransform.scale(ratio, ratio);
      }
      glyph.paths.forEach(path => {
        glyphPath.commands.push(
          ...path.toAbs().matrix(...glyphPathTransform.toArray()).commands
        );
      });
      if (this._options.centerHorizontally) {
        const bounds = glyphPath.getBounds();

        glyphPath.translate(
          (glyph.width - (bounds.maxX - bounds.minX)) / 2 - bounds.minX
        );
      }
      delete glyph.paths;
      glyph.unicode.forEach((unicode, i) => {
        const unicodeStr = ucs2
          .decode(unicode)
          .map(point => '&#x' + point.toString(16).toUpperCase() + ';')
          .join('');
        const d = glyphPath.round(this._options.round).encode();

        this.push(
          '    <glyph glyph-name="' +
            glyph.name +
            (0 === i ? '' : '-' + i) +
            '"\n' +
            '      unicode="' +
            unicodeStr +
            '"\n' +
            '      horiz-adv-x="' +
            glyph.width +
            '" d="' +
            d +
            '" />\n'
        );
      });
    });
    this.push('  </font>\n' + '</defs>\n' + '</svg>\n');
    this.log('Font created');
    if ('function' === typeof this._options.callback) {
      this._options.callback(this.glyphs);
    }
    svgFontFlushCallback();
  }
}

module.exports = SVGIcons2SVGFontStream;