override public Result decodeRow(int rowNumber,
BitArray row,
Hashtable hints)
{
// Compute this location once and reuse it on multiple implementations
int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
if (startGuardPattern == null)
{
return(null);
}
foreach (UPCEANReader reader in readers)
{
Result result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
if (result == null)
{
continue;
}
// Special case: a 12-digit code encoded in UPC-A is identical to a "0"
// followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
// UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
// Individually these are correct and their readers will both read such a code
// and correctly call it EAN-13, or UPC-A, respectively.
//
// In this case, if we've been looking for both types, we'd like to call it
// a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
// UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
// result if appropriate.
//
// But, don't return UPC-A if UPC-A was not a requested format!
bool ean13MayBeUPCA =
result.BarcodeFormat == BarcodeFormat.EAN_13 &&
result.Text[0] == '0';
var possibleFormats =
hints == null || !hints.Contains(DecodeHintType.POSSIBLE_FORMATS) ? null : (ArrayList)hints[DecodeHintType.POSSIBLE_FORMATS];
bool canReturnUPCA = possibleFormats == null || possibleFormats.Contains(BarcodeFormat.UPC_A);
if (ean13MayBeUPCA && canReturnUPCA)
{
// Transfer the metdata across
var resultUPCA = new Result(result.Text.Substring(1),
result.RawBytes,
result.ResultPoints,
BarcodeFormat.UPC_A);
resultUPCA.putAllMetadata(result.ResultMetadata);
return(resultUPCA);
}
return(result);
}
return(null);
}
