public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
// Compute this location once and reuse it on multiple implementations
int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
int size = readers.Count;
for (int i = 0; i < size; i++)
{
UPCEANReader reader = (UPCEANReader)readers[i];
Result result;
try
{
result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
}
catch (ReaderException)
{
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.
if (result.BarcodeFormat.Equals(BarcodeFormat.EAN_13) && result.Text[0] == '0')
{
return(new Result(result.Text.Substring(1), null, result.ResultPoints, BarcodeFormat.UPC_A));
}
return(result);
}
throw ReaderException.Instance;
}