/// <summary>Create a QR-code object with unitialized parameters</summary>
public QRCode()
{
mode = null;
ecLevel = null;
version = -1;
matrixWidth = -1;
maskPattern = -1;
numTotalBytes = -1;
numDataBytes = -1;
numECBytes = -1;
numRSBlocks = -1;
matrix = null;
}
/// <exception cref="iText.Barcodes.Qrcode.WriterException"/>
private static int ChooseMaskPattern(BitVector bits, ErrorCorrectionLevel ecLevel, int version, ByteMatrix
matrix)
{
int minPenalty = int.MaxValue;
// Lower penalty is better.
int bestMaskPattern = -1;
// We try all mask patterns to choose the best one.
for (int maskPattern = 0; maskPattern < QRCode.NUM_MASK_PATTERNS; maskPattern++)
{
MatrixUtil.BuildMatrix(bits, ecLevel, version, maskPattern, matrix);
int penalty = CalculateMaskPenalty(matrix);
if (penalty < minPenalty)
{
minPenalty = penalty;
bestMaskPattern = maskPattern;
}
}
return(bestMaskPattern);
}
/// <summary>Initialize "qrCode" according to "numInputBytes", "ecLevel", and "mode".</summary>
/// <remarks>
/// Initialize "qrCode" according to "numInputBytes", "ecLevel", and "mode". On success,
/// modify "qrCode".
/// </remarks>
/// <exception cref="iText.Barcodes.Qrcode.WriterException"/>
private static void InitQRCode(int numInputBytes, ErrorCorrectionLevel ecLevel, int desiredMinVersion, Mode
mode, QRCode qrCode)
{
qrCode.SetECLevel(ecLevel);
qrCode.SetMode(mode);
// In the following comments, we use numbers of Version 7-H.
for (int versionNum = desiredMinVersion; versionNum <= 40; versionNum++)
{
Version version = Version.GetVersionForNumber(versionNum);
// numBytes = 196
int numBytes = version.GetTotalCodewords();
// getNumECBytes = 130
Version.ECBlocks ecBlocks = version.GetECBlocksForLevel(ecLevel);
int numEcBytes = ecBlocks.GetTotalECCodewords();
// getNumRSBlocks = 5
int numRSBlocks = ecBlocks.GetNumBlocks();
// getNumDataBytes = 196 - 130 = 66
int numDataBytes = numBytes - numEcBytes;
// We want to choose the smallest version which can contain data of "numInputBytes" + some
// extra bits for the header (mode info and length info). The header can be three bytes
// (precisely 4 + 16 bits) at most. Hence we do +3 here.
if (numDataBytes >= numInputBytes + 3)
{
// Yay, we found the proper rs block info!
qrCode.SetVersion(versionNum);
qrCode.SetNumTotalBytes(numBytes);
qrCode.SetNumDataBytes(numDataBytes);
qrCode.SetNumRSBlocks(numRSBlocks);
// getNumECBytes = 196 - 66 = 130
qrCode.SetNumECBytes(numEcBytes);
// matrix width = 21 + 6 * 4 = 45
qrCode.SetMatrixWidth(version.GetDimensionForVersion());
return;
}
}
throw new WriterException("Cannot find proper rs block info (input data too big?)");
}
/// <summary>Set the error correction level of th QR code.</summary>
/// <remarks>
/// Set the error correction level of th QR code.
/// Possible error correction level values ranked from lowest error correction capability to highest: L, M, Q, H
/// </remarks>
/// <param name="value">new error correction level</param>
public void SetECLevel(ErrorCorrectionLevel value)
{
ecLevel = value;
}
/// <summary>Encode "bytes" with the error correction level "ecLevel".</summary>
/// <remarks>
/// Encode "bytes" with the error correction level "ecLevel". The encoding mode will be chosen
/// internally by chooseMode(). On success, store the result in "qrCode".
/// We recommend you to use QRCode.EC_LEVEL_L (the lowest level) for
/// "getECLevel" since our primary use is to show QR code on desktop screens. We don't need very
/// strong error correction for this purpose.
/// Note that there is no way to encode bytes in MODE_KANJI. We might want to add EncodeWithMode()
/// with which clients can specify the encoding mode. For now, we don't need the functionality.
/// </remarks>
/// <exception cref="iText.Barcodes.Qrcode.WriterException"/>
public static void Encode(String content, ErrorCorrectionLevel ecLevel, QRCode qrCode)
{
Encode(content, ecLevel, null, qrCode);
}
/// <summary>Encode "bytes" with the error correction level "ecLevel".</summary>
/// <remarks>
/// Encode "bytes" with the error correction level "ecLevel". The encoding mode will be chosen
/// internally by chooseMode(). On success, store the result in "qrCode".
/// <p>
/// We recommend you to use QRCode.EC_LEVEL_L (the lowest level) for
/// "getECLevel" since our primary use is to show QR code on desktop screens. We don't need very
/// strong error correction for this purpose.
/// <p>
/// Note that there is no way to encode bytes in MODE_KANJI. We might want to add EncodeWithMode()
/// with which clients can specify the encoding mode. For now, we don't need the functionality.
/// </remarks>
/// <param name="content">String to encode</param>
/// <param name="ecLevel">Error-correction level to use</param>
/// <param name="hints">Optional Map containing encoding and suggested minimum version to use</param>
/// <param name="qrCode">QR code to store the result in</param>
/// <exception cref="WriterException"/>
/// <exception cref="iText.Barcodes.Qrcode.WriterException"/>
public static void Encode(String content, ErrorCorrectionLevel ecLevel, IDictionary <EncodeHintType, Object
> hints, QRCode qrCode)
{
String encoding = hints == null ? null : (String)hints.Get(EncodeHintType.CHARACTER_SET);
if (encoding == null)
{
encoding = DEFAULT_BYTE_MODE_ENCODING;
}
int desiredMinVersion = (hints == null || hints.Get(EncodeHintType.MIN_VERSION_NR) == null) ? 1 : (int)hints
.Get(EncodeHintType.MIN_VERSION_NR);
//Check if desired level is within bounds of [1,40]
if (desiredMinVersion < 1)
{
desiredMinVersion = 1;
}
if (desiredMinVersion > 40)
{
desiredMinVersion = 40;
}
// Step 1: Choose the mode (encoding).
Mode mode = ChooseMode(content, encoding);
// Step 2: Append "bytes" into "dataBits" in appropriate encoding.
BitVector dataBits = new BitVector();
AppendBytes(content, mode, dataBits, encoding);
// Step 3: Initialize QR code that can contain "dataBits".
int numInputBytes = dataBits.SizeInBytes();
InitQRCode(numInputBytes, ecLevel, desiredMinVersion, mode, qrCode);
// Step 4: Build another bit vector that contains header and data.
BitVector headerAndDataBits = new BitVector();
// Step 4.5: Append ECI message if applicable
if (mode == Mode.BYTE && !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding))
{
CharacterSetECI eci = CharacterSetECI.GetCharacterSetECIByName(encoding);
if (eci != null)
{
AppendECI(eci, headerAndDataBits);
}
}
AppendModeInfo(mode, headerAndDataBits);
int numLetters = mode.Equals(Mode.BYTE) ? dataBits.SizeInBytes() : content.Length;
AppendLengthInfo(numLetters, qrCode.GetVersion(), mode, headerAndDataBits);
headerAndDataBits.AppendBitVector(dataBits);
// Step 5: Terminate the bits properly.
TerminateBits(qrCode.GetNumDataBytes(), headerAndDataBits);
// Step 6: Interleave data bits with error correction code.
BitVector finalBits = new BitVector();
InterleaveWithECBytes(headerAndDataBits, qrCode.GetNumTotalBytes(), qrCode.GetNumDataBytes(), qrCode.GetNumRSBlocks
(), finalBits);
// Step 7: Choose the mask pattern and set to "qrCode".
ByteMatrix matrix = new ByteMatrix(qrCode.GetMatrixWidth(), qrCode.GetMatrixWidth());
qrCode.SetMaskPattern(ChooseMaskPattern(finalBits, qrCode.GetECLevel(), qrCode.GetVersion(), matrix));
// Step 8. Build the matrix and set it to "qrCode".
MatrixUtil.BuildMatrix(finalBits, qrCode.GetECLevel(), qrCode.GetVersion(), qrCode.GetMaskPattern(), matrix
);
qrCode.SetMatrix(matrix);
// Step 9. Make sure we have a valid QR Code.
if (!qrCode.IsValid())
{
throw new WriterException("Invalid QR code: " + qrCode.ToString());
}
}
