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 (format != BarcodeFormat.UPC_A) {
    throw ArgumentError('Can only encode UPC-A, but got $format');
  }
  // Transform a UPC-A code into the equivalent EAN-13 code and write it that way
  return _subWriter.encode(
    '0$contents',
    BarcodeFormat.EAN_13,
    width,
    height,
    hints,
  );
}