decode static method

UQrDecodeResult decode(List<int> codewords)

Implementation

static UQrDecodeResult decode(List<int> codewords) {
  final StringBuffer result = StringBuffer();
  final List<int> byteSegments = <int>[];
  int? eci;
  int index = 0;

  while (index < codewords.length) {
    final int code = codewords[index++];
    switch (code) {
      case _textCompactionModeLatch:
        index = _textCompaction(codewords, index, result);
        break;
      case _byteCompactionModeLatch:
      case _byteCompactionModeLatch6:
        index = _byteCompaction(codewords, index, result, byteSegments);
        break;
      case _modeShiftToByteCompaction:
        if (index < codewords.length) {
          final int value = codewords[index++] % 256;
          result.writeCharCode(value);
          byteSegments.add(value);
        }
        break;
      case _numericCompactionModeLatch:
        index = _numericCompaction(codewords, index, result);
        break;
      case _eciCharset:
        if (index < codewords.length) eci = codewords[index++];
        break;
      case _beginMacroControlBlock:
      case _beginMacroOptionalField:
      case _macroTerminator:
        index = codewords.length;
        break;
      default:
        index = _textCompaction(codewords, index - 1, result);
        break;
    }
  }

  final String text = result.toString();
  return UQrDecodeResult(text: text, bytes: byteSegments.isNotEmpty ? Uint8List.fromList(byteSegments) : Uint8List.fromList(utf8.encode(text)), eci: eci);
}