/// <summary> 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.
/// </summary>
public static void Encode(System.String content, ErrorCorrectionLevel ecLevel, QRCode qrCode)
{
Encode(content, ecLevel, null, qrCode);
}
public static void Encode(System.String content, ErrorCorrectionLevel ecLevel, System.Collections.Hashtable hints, QRCode qrCode)
{
System.String encoding = hints == null?null:(System.String)hints[EncodeHintType.CHARACTER_SET];
if (encoding == null)
{
encoding = DEFAULT_BYTE_MODE_ENCODING;
}
// 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, 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.Version, mode, headerAndDataBits);
headerAndDataBits.appendBitVector(dataBits);
// Step 5: Terminate the bits properly.
TerminateBits(qrCode.NumDataBytes, headerAndDataBits);
// Step 6: Interleave data bits with error correction code.
BitVector finalBits = new BitVector();
InterleaveWithEcBytes(headerAndDataBits, qrCode.NumTotalBytes, qrCode.NumDataBytes, qrCode.NumRSBlocks, finalBits);
// Step 7: Choose the mask pattern and set to "qrCode".
ByteMatrix matrix = new ByteMatrix(qrCode.MatrixWidth, qrCode.MatrixWidth);
qrCode.MaskPattern = ChooseMaskPattern(finalBits, qrCode.ECLevel, qrCode.Version, matrix);
// Step 8. Build the matrix and set it to "qrCode".
MatrixUtil.buildMatrix(finalBits, qrCode.ECLevel, qrCode.Version, qrCode.MaskPattern, matrix);
qrCode.Matrix = matrix;
// Step 9. Make sure we have a valid QR Code.
if (!qrCode.Valid)
{
throw new WriterException(string.Format("Invalid QR code: {0}", qrCode));
}
}
/// <summary> Initialize "qrCode" according to "numInputBytes", "ecLevel", and "mode". On success,
/// modify "qrCode".
/// </summary>
private static void InitQrCode(int numInputBytes, ErrorCorrectionLevel ecLevel, Mode mode, QRCode qrCode)
{
qrCode.ECLevel = ecLevel;
qrCode.Mode = mode;
// In the following comments, we use numbers of Version 7-H.
for (int versionNum = 1; versionNum <= 40; versionNum++)
{
Version version = Version.getVersionForNumber(versionNum);
// numBytes = 196
int numBytes = version.TotalCodewords;
// getNumECBytes = 130
Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel);
int numEcBytes = ecBlocks.TotalECCodewords;
// getNumRSBlocks = 5
int numRSBlocks = ecBlocks.NumBlocks;
// 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.Version = versionNum;
qrCode.NumTotalBytes = numBytes;
qrCode.NumDataBytes = numDataBytes;
qrCode.NumRSBlocks = numRSBlocks;
// getNumECBytes = 196 - 66 = 130
qrCode.NumECBytes = numEcBytes;
// matrix width = 21 + 6 * 4 = 45
qrCode.MatrixWidth = version.DimensionForVersion;
return;
}
}
throw new WriterException("Cannot find proper rs block info (input data too big?)");
}
