SvgTransform.fromString constructor

SvgTransform.fromString(String? transform)

Implementation

factory SvgTransform.fromString(String? transform) {
  if (transform == null) {
    return none;
  }

  final mat = Matrix4.identity();

  for (final m in _transformRegExp.allMatches(transform)) {
    final name = m.group(1);
    final parameterList = SvgParser.splitDoubles(m.group(2)!).toList();

    switch (name) {
      case 'matrix':
        final mm = <double>[
          ...parameterList,
          ...List.filled(6 - parameterList.length, 0.0)
        ];

        mat.multiply(Matrix4(mm[0], mm[1], 0, 0, mm[2], mm[3], 0, 0, 0, 0, 1,
            0, mm[4], mm[5], 0, 1));
        break;
      case 'translate':
        final dx = parameterList[0];
        final dy = [...parameterList, .0][1];

        mat.multiply(Matrix4.identity()..translate(dx, dy));
        break;
      case 'scale':
        final sw = parameterList[0];
        final sh = [...parameterList, sw][1];

        mat.multiply(Matrix4.identity()..scale(sw, sh));
        break;
      case 'rotate':
        final degrees = parameterList[0];

        var ox = 0.0;
        var oy = 0.0;
        if (parameterList.length > 1) {
          // Rotation about the origin (ox, oy)
          ox = parameterList[1];
          oy = [...parameterList, .0][2];
          mat.translate(ox, oy);
        }

        mat.multiply(Matrix4.rotationZ(radians(degrees)));

        if (ox != 0 || oy != 0) {
          mat.translate(-ox, -oy);
        }
        break;

      case 'skewX':
        // assert(false, 'skewX');
        mat.multiply(Matrix4.skewX(radians(parameterList[0])));
        break;
      case 'skewY':
        // assert(false, 'skewY');
        mat.multiply(Matrix4.skewY(radians(parameterList[0])));
        break;
    }
  }

  return SvgTransform(mat);
}