public override Result decodeRow(int rowNumber, BitArray row, IDictionary <DecodeHintType, object> hints)
{
for (var index = 0; index < counters.Length; index++)
{
counters[index] = 0;
}
if (!setCounters(row))
{
return(null);
}
int startOffset = findStartPattern();
if (startOffset < 0)
{
return(null);
}
int nextStart = startOffset;
decodeRowResult.Length = 0;
do
{
int charOffset = toNarrowWidePattern(nextStart);
if (charOffset == -1)
{
return(null);
}
// Hack: We store the position in the alphabet table into a
// StringBuilder, so that we can access the decoded patterns in
// validatePattern. We'll translate to the actual characters later.
decodeRowResult.Append((char)charOffset);
nextStart += 8;
// Stop as soon as we see the end character.
if (decodeRowResult.Length > 1 &&
arrayContains(STARTEND_ENCODING, ALPHABET[charOffset]))
{
break;
}
} while (nextStart < counterLength); // no fixed end pattern so keep on reading while data is available
// Look for whitespace after pattern:
int trailingWhitespace = counters[nextStart - 1];
int lastPatternSize = 0;
for (int i = -8; i < -1; i++)
{
lastPatternSize += counters[nextStart + i];
}
// We need to see whitespace equal to 50% of the last pattern size,
// otherwise this is probably a false positive. The exception is if we are
// at the end of the row. (I.e. the barcode barely fits.)
if (nextStart < counterLength && trailingWhitespace < lastPatternSize / 2)
{
return(null);
}
if (!validatePattern(startOffset))
{
return(null);
}
// Translate character table offsets to actual characters.
for (int i = 0; i < decodeRowResult.Length; i++)
{
decodeRowResult[i] = ALPHABET[decodeRowResult[i]];
}
// Ensure a valid start and end character
char startchar = decodeRowResult[0];
if (!arrayContains(STARTEND_ENCODING, startchar))
{
return(null);
}
char endchar = decodeRowResult[decodeRowResult.Length - 1];
if (!arrayContains(STARTEND_ENCODING, endchar))
{
return(null);
}
// remove stop/start characters character and check if a long enough string is contained
if (decodeRowResult.Length <= MIN_CHARACTER_LENGTH)
{
// Almost surely a false positive ( start + stop + at least 1 character)
return(null);
}
if (!SupportClass.GetValue(hints, DecodeHintType.RETURN_CODABAR_START_END, false))
{
decodeRowResult.Remove(decodeRowResult.Length - 1, 1);
decodeRowResult.Remove(0, 1);
}
int runningCount = 0;
for (int i = 0; i < startOffset; i++)
{
runningCount += counters[i];
}
float left = runningCount;
for (int i = startOffset; i < nextStart - 1; i++)
{
runningCount += counters[i];
}
float right = runningCount;
var resultPointCallback = SupportClass.GetValue(hints, DecodeHintType.NEED_RESULT_POINT_CALLBACK, (ResultPointCallback)null);
if (resultPointCallback != null)
{
resultPointCallback(new ResultPoint(left, rowNumber));
resultPointCallback(new ResultPoint(right, rowNumber));
}
return(new Result(
decodeRowResult.ToString(),
null,
new[]
{
new ResultPoint(left, rowNumber),
new ResultPoint(right, rowNumber)
},
BarcodeFormat.CODABAR));
}
