public static void encode(String content, ErrorCorrectionLevel ecLevel, Dictionary<EncodeHintType, Object> hints,
QRCode qrCode)
{
String encoding = hints == null ? null : (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.
var 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.
var 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.
var finalBits = new BitVector();
interleaveWithECBytes(headerAndDataBits, qrCode.NumTotalBytes, qrCode.NumDataBytes, qrCode.NumRSBlocks,
finalBits);
// Step 7: Choose the mask pattern and set to "qrCode".
var 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("Invalid QR code: " + qrCode);
}
}
public DecoderResult(sbyte[] rawBytes, String text, List<byte[]> byteSegments, ErrorCorrectionLevel ecLevel)
{
if (rawBytes == null && text == null)
{
throw new ArgumentException();
}
this.rawBytes = rawBytes;
this.text = text;
this.byteSegments = byteSegments;
this.ecLevel = ecLevel;
}
public QRCode()
{
mode = null;
ecLevel = null;
version = - 1;
matrixWidth = - 1;
maskPattern = - 1;
numTotalBytes = - 1;
numDataBytes = - 1;
numECBytes = - 1;
numRSBlocks = - 1;
matrix = null;
}
/// <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(String content, ErrorCorrectionLevel ecLevel, QRCode qrCode)
{
encode(content, ecLevel, null, 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?)");
}
private static int chooseMaskPattern(BitVector bits, ErrorCorrectionLevel ecLevel, int version,
ByteMatrix matrix)
{
int minPenalty = Int32.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;
}
internal static DecoderResult decode(sbyte[] bytes, Version version, ErrorCorrectionLevel ecLevel)
{
var bits = new BitSource(bytes);
var result = new StringBuilder(50);
CharacterSetECI currentCharacterSetECI = null;
bool fc1InEffect = false;
var byteSegments = new List<byte[]>(1);
Mode mode;
do
{
// While still another segment to read...
if (bits.available() < 4)
{
// OK, assume we're done. Really, a TERMINATOR mode should have been recorded here
mode = Mode.TERMINATOR;
}
else
{
try
{
mode = Mode.forBits(bits.readBits(4)); // mode is encoded by 4 bits
}
catch (ArgumentException)
{
throw ReaderException.Instance;
}
}
if (!mode.Equals(Mode.TERMINATOR))
{
if (mode.Equals(Mode.FNC1_FIRST_POSITION) || mode.Equals(Mode.FNC1_SECOND_POSITION))
{
// We do little with FNC1 except alter the parsed result a bit according to the spec
fc1InEffect = true;
}
else if (mode.Equals(Mode.STRUCTURED_APPEND))
{
// not really supported; all we do is ignore it
// Read next 8 bits (symbol sequence #) and 8 bits (parity data), then continue
bits.readBits(16);
}
else if (mode.Equals(Mode.ECI))
{
// Count doesn't apply to ECI
int value_Renamed = parseECIValue(bits);
currentCharacterSetECI = CharacterSetECI.getCharacterSetECIByValue(value_Renamed);
if (currentCharacterSetECI == null)
{
throw ReaderException.Instance;
}
}
else
{
// How many characters will follow, encoded in this mode?
int count = bits.readBits(mode.getCharacterCountBits(version));
if (mode.Equals(Mode.NUMERIC))
{
decodeNumericSegment(bits, result, count);
}
else if (mode.Equals(Mode.ALPHANUMERIC))
{
decodeAlphanumericSegment(bits, result, count, fc1InEffect);
}
else if (mode.Equals(Mode.BYTE))
{
decodeByteSegment(bits, result, count, currentCharacterSetECI, byteSegments);
}
else if (mode.Equals(Mode.KANJI))
{
decodeKanjiSegment(bits, result, count);
}
else
{
throw ReaderException.Instance;
}
}
}
} while (!mode.Equals(Mode.TERMINATOR));
return new DecoderResult(bytes, result.ToString(), (byteSegments.Count == 0) ? null : byteSegments, ecLevel);
}
// Make bit vector of type information. On success, store the result in "bits" and return true.
// Encode error correction level and mask pattern. See 8.9 of
// JISX0510:2004 (p.45) for details.
public static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int maskPattern, BitVector bits)
{
if (!QRCode.isValidMaskPattern(maskPattern))
{
throw new WriterException("Invalid mask pattern");
}
int typeInfo = (ecLevel.Bits << 3) | maskPattern;
bits.appendBits(typeInfo, 5);
int bchCode = calculateBCHCode(typeInfo, TYPE_INFO_POLY);
bits.appendBits(bchCode, 10);
var maskBits = new BitVector();
maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15);
bits.xor(maskBits);
if (bits.size() != 15)
{
// Just in case.
throw new WriterException("should not happen but we got: " + bits.size());
}
}
// Embed type information. On success, modify the matrix.
public static void embedTypeInfo(ErrorCorrectionLevel ecLevel, int maskPattern, ByteMatrix matrix)
{
var typeInfoBits = new BitVector();
makeTypeInfoBits(ecLevel, maskPattern, typeInfoBits);
for (int i = 0; i < typeInfoBits.size(); ++i)
{
// Place bits in LSB to MSB order. LSB (least significant bit) is the last value in
// "typeInfoBits".
int bit = typeInfoBits.at(typeInfoBits.size() - 1 - i);
// Type info bits at the left top corner. See 8.9 of JISX0510:2004 (p.46).
int x1 = TYPE_INFO_COORDINATES[i][0];
int y1 = TYPE_INFO_COORDINATES[i][1];
matrix.set_Renamed(x1, y1, bit);
if (i < 8)
{
// Right top corner.
int x2 = matrix.Width - i - 1;
int y2 = 8;
matrix.set_Renamed(x2, y2, bit);
}
else
{
// Left bottom corner.
int x2 = 8;
int y2 = matrix.Height - 7 + (i - 8);
matrix.set_Renamed(x2, y2, bit);
}
}
}
// Build 2D matrix of QR Code from "dataBits" with "ecLevel", "version" and "getMaskPattern". On
// success, store the result in "matrix" and return true.
public static void buildMatrix(BitVector dataBits, ErrorCorrectionLevel ecLevel, int version, int maskPattern,
ByteMatrix matrix)
{
clearMatrix(matrix);
embedBasicPatterns(version, matrix);
// Type information appear with any version.
embedTypeInfo(ecLevel, maskPattern, matrix);
// Version info appear if version >= 7.
maybeEmbedVersionInfo(version, matrix);
// Data should be embedded at end.
embedDataBits(dataBits, maskPattern, matrix);
}
public ECBlocks getECBlocksForLevel(ErrorCorrectionLevel ecLevel)
{
return ecBlocks[ecLevel.ordinal()];
}
