encode method

@override BitMatrix encode(String contents, BarcodeFormat format, int width, int height, [ Map<EncodeHintType, Object>? hints, ])

@param contents The contents to encode in the barcode @param format The barcode format to generate @param width The preferred width in pixels @param height The preferred height in pixels @param hints Additional parameters to supply to the encoder @return BitMatrix representing encoded barcode image @throws WriterException if contents cannot be encoded legally in a format

Implementation

@override
BitMatrix encode(
  String contents,
  BarcodeFormat format,
  int width,
  int height, [
  Map<EncodeHintType, Object>? hints,
]) {
  if (contents.isEmpty) {
    throw ArgumentError('Found empty contents');
  }

  if (format != BarcodeFormat.DATA_MATRIX) {
    throw ArgumentError('Can only encode DATA_MATRIX, but got $format');
  }

  if (width < 0 || height < 0) {
    throw ArgumentError(
      "Requested dimensions can't be negative: $width" 'x$height',
    );
  }

  // Try to get force shape & min / max size
  SymbolShapeHint shape = SymbolShapeHint.FORCE_NONE;
  Dimension? minSize;
  Dimension? maxSize;
  if (hints != null) {
    final requestedShape =
        hints[EncodeHintType.DATA_MATRIX_SHAPE] as SymbolShapeHint?;
    if (requestedShape != null) {
      shape = requestedShape;
    }

    // ignore: deprecated_member_use_from_same_package
    final requestedMinSize = hints[EncodeHintType.MIN_SIZE] as Dimension?;
    if (requestedMinSize != null) {
      minSize = requestedMinSize;
    }

    // ignore: deprecated_member_use_from_same_package
    final requestedMaxSize = hints[EncodeHintType.MAX_SIZE] as Dimension?;
    if (requestedMaxSize != null) {
      maxSize = requestedMaxSize;
    }
  }

  //1. step: Data encodation
  String encoded;

  final hasCompactionHint = hints != null &&
      hints.containsKey(EncodeHintType.DATA_MATRIX_COMPACT) &&
      (hints[EncodeHintType.DATA_MATRIX_COMPACT] as bool);
  if (hasCompactionHint) {
    final hasGS1FormatHint = hints.containsKey(EncodeHintType.GS1_FORMAT) &&
        (hints[EncodeHintType.GS1_FORMAT] as bool);

    Encoding? charset;
    final hasEncodingHint = hints.containsKey(EncodeHintType.CHARACTER_SET);
    if (hasEncodingHint) {
      charset = (hints[EncodeHintType.CHARACTER_SET] as Encoding?);
    }
    encoded = MinimalEncoder.encodeHighLevel(
      contents,
      charset,
      hasGS1FormatHint ? 0x1D : -1,
      shape,
    );
  } else {
    encoded =
        HighLevelEncoder.encodeHighLevel(contents, shape, minSize, maxSize);
  }

  final symbolInfo =
      SymbolInfo.lookup(encoded.length, shape, minSize, maxSize, true);

  //2. step: ECC generation
  final codewords = ErrorCorrection.encodeECC200(encoded, symbolInfo!);

  //3. step: Module placement in Matrix
  final placement = DefaultPlacement(
    codewords,
    symbolInfo.symbolDataWidth,
    symbolInfo.symbolDataHeight,
  );
  placement.place();

  //4. step: low-level encoding
  return _encodeLowLevel(placement, symbolInfo, width, height);
}