internal static DecoderResult decode(byte[] bytes)
{
BitSource bits = new BitSource(bytes);
StringBuilder result = new StringBuilder(100);
StringBuilder resultTrailer = new StringBuilder(0);
List<byte[]> byteSegments = new List<byte[]>(1);
Mode mode = Mode.ASCII_ENCODE;
do
{
if (mode == Mode.ASCII_ENCODE)
{
if (!decodeAsciiSegment(bits, result, resultTrailer, out mode))
return null;
}
else
{
switch (mode)
{
case Mode.C40_ENCODE:
if (!decodeC40Segment(bits, result))
return null;
break;
case Mode.TEXT_ENCODE:
if (!decodeTextSegment(bits, result))
return null;
break;
case Mode.ANSIX12_ENCODE:
if (!decodeAnsiX12Segment(bits, result))
return null;
break;
case Mode.EDIFACT_ENCODE:
if (!decodeEdifactSegment(bits, result))
return null;
break;
case Mode.BASE256_ENCODE:
if (!decodeBase256Segment(bits, result, byteSegments))
return null;
break;
default:
return null;
}
mode = Mode.ASCII_ENCODE;
}
} while (mode != Mode.PAD_ENCODE && bits.available() > 0);
if (resultTrailer.Length > 0)
{
result.Append(resultTrailer.ToString());
}
return new DecoderResult(bytes, result.ToString(), byteSegments.Count == 0 ? null : byteSegments, null);
}
public void testSource()
{
byte[] bytes = { 1, 2, 3, 4, 5 };
BitSource source = new BitSource(bytes);
Assert.AreEqual(40, source.available());
Assert.AreEqual(0, source.readBits(1));
Assert.AreEqual(39, source.available());
Assert.AreEqual(0, source.readBits(6));
Assert.AreEqual(33, source.available());
Assert.AreEqual(1, source.readBits(1));
Assert.AreEqual(32, source.available());
Assert.AreEqual(2, source.readBits(8));
Assert.AreEqual(24, source.available());
Assert.AreEqual(12, source.readBits(10));
Assert.AreEqual(14, source.available());
Assert.AreEqual(16, source.readBits(8));
Assert.AreEqual(6, source.available());
Assert.AreEqual(5, source.readBits(6));
Assert.AreEqual(0, source.available());
}
/// <summary>
/// See ISO 16022:2006, 5.2.8 and Annex C Table C.3
/// </summary>
private static bool decodeEdifactSegment(BitSource bits, StringBuilder result)
{
do
{
// If there is only two or less bytes left then it will be encoded as ASCII
if (bits.available() <= 16)
{
return true;
}
for (int i = 0; i < 4; i++)
{
int edifactValue = bits.readBits(6);
// Check for the unlatch character
if (edifactValue == 0x1F)
{ // 011111
// Read rest of byte, which should be 0, and stop
int bitsLeft = 8 - bits.BitOffset;
if (bitsLeft != 8)
{
bits.readBits(bitsLeft);
}
return true;
}
if ((edifactValue & 0x20) == 0)
{ // no 1 in the leading (6th) bit
edifactValue |= 0x40; // Add a leading 01 to the 6 bit binary value
}
result.Append((char)edifactValue);
}
} while (bits.available() > 0);
return true;
}
/// <summary>
/// See ISO 16022:2006, 5.2.7
/// </summary>
private static bool decodeAnsiX12Segment(BitSource bits,
StringBuilder result)
{
// Three ANSI X12 values are encoded in a 16-bit value as
// (1600 * C1) + (40 * C2) + C3 + 1
int[] cValues = new int[3];
do
{
// If there is only one byte left then it will be encoded as ASCII
if (bits.available() == 8)
{
return true;
}
int firstByte = bits.readBits(8);
if (firstByte == 254)
{ // Unlatch codeword
return true;
}
parseTwoBytes(firstByte, bits.readBits(8), cValues);
for (int i = 0; i < 3; i++)
{
int cValue = cValues[i];
if (cValue == 0)
{ // X12 segment terminator <CR>
result.Append('\r');
}
else if (cValue == 1)
{ // X12 segment separator *
result.Append('*');
}
else if (cValue == 2)
{ // X12 sub-element separator >
result.Append('>');
}
else if (cValue == 3)
{ // space
result.Append(' ');
}
else if (cValue < 14)
{ // 0 - 9
result.Append((char)(cValue + 44));
}
else if (cValue < 40)
{ // A - Z
result.Append((char)(cValue + 51));
}
else
{
return false;
}
}
} while (bits.available() > 0);
return true;
}
/// <summary>
/// See ISO 16022:2006, 5.2.6 and Annex C, Table C.2
/// </summary>
private static bool decodeTextSegment(BitSource bits, StringBuilder result)
{
// Three Text values are encoded in a 16-bit value as
// (1600 * C1) + (40 * C2) + C3 + 1
// TODO(bbrown): The Upper Shift with Text doesn't work in the 4 value scenario all the time
bool upperShift = false;
int[] cValues = new int[3];
int shift = 0;
do
{
// If there is only one byte left then it will be encoded as ASCII
if (bits.available() == 8)
{
return true;
}
int firstByte = bits.readBits(8);
if (firstByte == 254)
{
// Unlatch codeword
return true;
}
parseTwoBytes(firstByte, bits.readBits(8), cValues);
for (int i = 0; i < 3; i++)
{
int cValue = cValues[i];
switch (shift)
{
case 0:
if (cValue < 3)
{
shift = cValue + 1;
}
else if (cValue < TEXT_BASIC_SET_CHARS.Length)
{
char textChar = TEXT_BASIC_SET_CHARS[cValue];
if (upperShift)
{
result.Append((char)(textChar + 128));
upperShift = false;
}
else
{
result.Append(textChar);
}
}
else
{
return false;
}
break;
case 1:
if (upperShift)
{
result.Append((char)(cValue + 128));
upperShift = false;
}
else
{
result.Append((char)cValue);
}
shift = 0;
break;
case 2:
// Shift 2 for Text is the same encoding as C40
if (cValue < C40_SHIFT2_SET_CHARS.Length)
{
char c40char = C40_SHIFT2_SET_CHARS[cValue];
if (upperShift)
{
result.Append((char)(c40char + 128));
upperShift = false;
}
else
{
result.Append(c40char);
}
}
else if (cValue == 27)
{ // FNC1
result.Append((char)29); // translate as ASCII 29
}
else if (cValue == 30)
{ // Upper Shift
upperShift = true;
}
else
{
return false;
}
shift = 0;
break;
case 3:
if (cValue < TEXT_SHIFT3_SET_CHARS.Length)
{
char textChar = TEXT_SHIFT3_SET_CHARS[cValue];
if (upperShift)
{
result.Append((char)(textChar + 128));
upperShift = false;
}
else
{
result.Append(textChar);
}
shift = 0;
}
else
{
return false;
}
break;
default:
return false;
}
}
} while (bits.available() > 0);
return true;
}
/// <summary>
/// See ISO 16022:2006, 5.2.3 and Annex C, Table C.2
/// </summary>
private static bool decodeAsciiSegment(BitSource bits,
StringBuilder result,
StringBuilder resultTrailer,
out Mode mode)
{
bool upperShift = false;
mode = Mode.ASCII_ENCODE;
do
{
int oneByte = bits.readBits(8);
if (oneByte == 0)
{
return false;
}
else if (oneByte <= 128)
{ // ASCII data (ASCII value + 1)
if (upperShift)
{
oneByte += 128;
//upperShift = false;
}
result.Append((char)(oneByte - 1));
mode = Mode.ASCII_ENCODE;
return true;
}
else if (oneByte == 129)
{ // Pad
mode = Mode.PAD_ENCODE;
return true;
}
else if (oneByte <= 229)
{ // 2-digit data 00-99 (Numeric Value + 130)
int value = oneByte - 130;
if (value < 10)
{ // padd with '0' for single digit values
result.Append('0');
}
result.Append(value);
}
else if (oneByte == 230)
{ // Latch to C40 encodation
mode = Mode.C40_ENCODE;
return true;
}
else if (oneByte == 231)
{ // Latch to Base 256 encodation
mode = Mode.BASE256_ENCODE;
return true;
}
else if (oneByte == 232)
{
// FNC1
result.Append((char)29); // translate as ASCII 29
}
else if (oneByte == 233 || oneByte == 234)
{
// Structured Append, Reader Programming
// Ignore these symbols for now
//throw ReaderException.Instance;
}
else if (oneByte == 235)
{ // Upper Shift (shift to Extended ASCII)
upperShift = true;
}
else if (oneByte == 236)
{ // 05 Macro
result.Append("[)>\u001E05\u001D");
resultTrailer.Insert(0, "\u001E\u0004");
}
else if (oneByte == 237)
{ // 06 Macro
result.Append("[)>\u001E06\u001D");
resultTrailer.Insert(0, "\u001E\u0004");
}
else if (oneByte == 238)
{ // Latch to ANSI X12 encodation
mode = Mode.ANSIX12_ENCODE;
return true;
}
else if (oneByte == 239)
{ // Latch to Text encodation
mode = Mode.TEXT_ENCODE;
return true;
}
else if (oneByte == 240)
{ // Latch to EDIFACT encodation
mode = Mode.EDIFACT_ENCODE;
return true;
}
else if (oneByte == 241)
{ // ECI Character
// TODO(bbrown): I think we need to support ECI
//throw ReaderException.Instance;
// Ignore this symbol for now
}
else if (oneByte >= 242)
{ // Not to be used in ASCII encodation
// ... but work around encoders that end with 254, latch back to ASCII
if (oneByte != 254 || bits.available() != 0)
{
return false;
}
}
} while (bits.available() > 0);
mode = Mode.ASCII_ENCODE;
return true;
}
private static int parseECIValue(BitSource bits)
{
int firstByte = bits.readBits(8);
if ((firstByte & 0x80) == 0)
{
// just one byte
return firstByte & 0x7F;
}
if ((firstByte & 0xC0) == 0x80)
{
// two bytes
int secondByte = bits.readBits(8);
return ((firstByte & 0x3F) << 8) | secondByte;
}
if ((firstByte & 0xE0) == 0xC0)
{
// three bytes
int secondThirdBytes = bits.readBits(16);
return ((firstByte & 0x1F) << 16) | secondThirdBytes;
}
throw new ArgumentException("Bad ECI bits starting with byte " + firstByte);
}
private static bool decodeNumericSegment(BitSource bits,
StringBuilder result,
int count)
{
// Read three digits at a time
while (count >= 3)
{
// Each 10 bits encodes three digits
if (bits.available() < 10)
{
return false;
}
int threeDigitsBits = bits.readBits(10);
if (threeDigitsBits >= 1000)
{
return false;
}
result.Append(toAlphaNumericChar(threeDigitsBits / 100));
result.Append(toAlphaNumericChar((threeDigitsBits / 10) % 10));
result.Append(toAlphaNumericChar(threeDigitsBits % 10));
count -= 3;
}
if (count == 2)
{
// Two digits left over to read, encoded in 7 bits
if (bits.available() < 7)
{
return false;
}
int twoDigitsBits = bits.readBits(7);
if (twoDigitsBits >= 100)
{
return false;
}
result.Append(toAlphaNumericChar(twoDigitsBits / 10));
result.Append(toAlphaNumericChar(twoDigitsBits % 10));
}
else if (count == 1)
{
// One digit left over to read
if (bits.available() < 4)
{
return false;
}
int digitBits = bits.readBits(4);
if (digitBits >= 10)
{
return false;
}
result.Append(toAlphaNumericChar(digitBits));
}
return true;
}
private static bool decodeKanjiSegment(BitSource bits,
StringBuilder result,
int count)
{
// Don't crash trying to read more bits than we have available.
if (count * 13 > bits.available())
{
return false;
}
// Each character will require 2 bytes. Read the characters as 2-byte pairs
// and decode as Shift_JIS afterwards
byte[] buffer = new byte[2 * count];
int offset = 0;
while (count > 0)
{
// Each 13 bits encodes a 2-byte character
int twoBytes = bits.readBits(13);
int assembledTwoBytes = ((twoBytes / 0x0C0) << 8) | (twoBytes % 0x0C0);
if (assembledTwoBytes < 0x01F00)
{
// In the 0x8140 to 0x9FFC range
assembledTwoBytes += 0x08140;
}
else
{
// In the 0xE040 to 0xEBBF range
assembledTwoBytes += 0x0C140;
}
buffer[offset] = (byte)(assembledTwoBytes >> 8);
buffer[offset + 1] = (byte)assembledTwoBytes;
offset += 2;
count--;
}
// Shift_JIS may not be supported in some environments:
try
{
result.Append(Encoding.GetEncoding(StringUtils.SHIFT_JIS).GetString(buffer, 0, buffer.Length));
}
catch (Exception)
{
return false;
}
return true;
}
private static bool decodeAlphanumericSegment(BitSource bits,
StringBuilder result,
int count,
bool fc1InEffect)
{
// Read two characters at a time
int start = result.Length;
while (count > 1)
{
if (bits.available() < 11)
{
return false;
}
int nextTwoCharsBits = bits.readBits(11);
result.Append(toAlphaNumericChar(nextTwoCharsBits / 45));
result.Append(toAlphaNumericChar(nextTwoCharsBits % 45));
count -= 2;
}
if (count == 1)
{
// special case: one character left
if (bits.available() < 6)
{
return false;
}
result.Append(toAlphaNumericChar(bits.readBits(6)));
}
// See section 6.4.8.1, 6.4.8.2
if (fc1InEffect)
{
// We need to massage the result a bit if in an FNC1 mode:
for (int i = start; i < result.Length; i++)
{
if (result[i] == '%')
{
if (i < result.Length - 1 && result[i + 1] == '%')
{
// %% is rendered as %
result.Remove(i + 1, 1);
}
else
{
// In alpha mode, % should be converted to FNC1 separator 0x1D
result.Remove(i, 1);
result.Insert(i, new[] { (char)0x1D });
}
}
}
}
return true;
}
private static bool decodeByteSegment(BitSource bits,
StringBuilder result,
int count,
IList<byte[]> byteSegments,
IDictionary<DecodeHintType, object> hints)
{
// Don't crash trying to read more bits than we have available.
if (count << 3 > bits.available())
{
return false;
}
byte[] readBytes = new byte[count];
for (int i = 0; i < count; i++)
{
readBytes[i] = (byte)bits.readBits(8);
}
String encoding;
encoding = StringUtils.guessEncoding(readBytes, hints);
try
{
result.Append(Encoding.GetEncoding(encoding).GetString(readBytes, 0, readBytes.Length));
}
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
catch (ArgumentException)
{
try
{
// Silverlight only supports a limited number of character sets, trying fallback to UTF-8
result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
}
catch (Exception)
{
return false;
}
}
#endif
#if WindowsCE
catch (PlatformNotSupportedException)
{
try
{
// WindowsCE doesn't support all encodings. But it is device depended.
// So we try here the some different ones
if (encoding == "ISO-8859-1")
{
result.Append(Encoding.GetEncoding(1252).GetString(readBytes, 0, readBytes.Length));
}
else
{
result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
}
}
catch (Exception)
{
return false;
}
}
#endif
catch (Exception)
{
return false;
}
byteSegments.Add(readBytes);
return true;
}
private static bool decodeKanjiSegment(BitSource bits,
StringBuilder result,
int count)
{
// Don't crash trying to read more bits than we have available.
if (count * 13 > bits.available())
{
return false;
}
// Each character will require 2 bytes. Read the characters as 2-byte pairs
// and decode as Shift_JIS afterwards
byte[] buffer = new byte[2 * count];
int offset = 0;
while (count > 0)
{
// Each 13 bits encodes a 2-byte character
int twoBytes = bits.readBits(13);
int assembledTwoBytes = ((twoBytes / 0x0C0) << 8) | (twoBytes % 0x0C0);
if (assembledTwoBytes < 0x01F00)
{
// In the 0x8140 to 0x9FFC range
assembledTwoBytes += 0x08140;
}
else
{
// In the 0xE040 to 0xEBBF range
assembledTwoBytes += 0x0C140;
}
buffer[offset] = (byte)(assembledTwoBytes >> 8);
buffer[offset + 1] = (byte)assembledTwoBytes;
offset += 2;
count--;
}
// Shift_JIS may not be supported in some environments:
try
{
result.Append(Encoding.GetEncoding(StringUtils.SHIFT_JIS).GetString(buffer, 0, buffer.Length));
}
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
catch (ArgumentException)
{
try
{
// Silverlight only supports a limited number of character sets, trying fallback to UTF-8
result.Append(Encoding.GetEncoding("UTF-8").GetString(buffer, 0, buffer.Length));
}
catch (Exception)
{
return false;
}
}
#endif
catch (Exception)
{
return false;
}
return true;
}
/// <summary>
/// See specification GBT 18284-2000
/// </summary>
/// <param name="bits">The bits.</param>
/// <param name="result">The result.</param>
/// <param name="count">The count.</param>
/// <returns></returns>
private static bool decodeHanziSegment(BitSource bits,
StringBuilder result,
int count)
{
// Don't crash trying to read more bits than we have available.
if (count * 13 > bits.available())
{
return false;
}
// Each character will require 2 bytes. Read the characters as 2-byte pairs
// and decode as GB2312 afterwards
byte[] buffer = new byte[2 * count];
int offset = 0;
while (count > 0)
{
// Each 13 bits encodes a 2-byte character
int twoBytes = bits.readBits(13);
int assembledTwoBytes = ((twoBytes / 0x060) << 8) | (twoBytes % 0x060);
if (assembledTwoBytes < 0x003BF)
{
// In the 0xA1A1 to 0xAAFE range
assembledTwoBytes += 0x0A1A1;
}
else
{
// In the 0xB0A1 to 0xFAFE range
assembledTwoBytes += 0x0A6A1;
}
buffer[offset] = (byte)((assembledTwoBytes >> 8) & 0xFF);
buffer[offset + 1] = (byte)(assembledTwoBytes & 0xFF);
offset += 2;
count--;
}
try
{
result.Append(Encoding.GetEncoding(StringUtils.GB2312).GetString(buffer, 0, buffer.Length));
}
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
catch (ArgumentException)
{
try
{
// Silverlight only supports a limited number of character sets, trying fallback to UTF-8
result.Append(Encoding.GetEncoding("UTF-8").GetString(buffer, 0, buffer.Length));
}
catch (Exception)
{
return false;
}
}
#endif
catch (Exception)
{
return false;
}
return true;
}
private static bool decodeByteSegment (BitSource bits,
StringBuilder result,
int count,
CharacterSetECI currentCharacterSetECI,
IList<byte[]> byteSegments,
IDictionary<DecodeHintType, object> hints)
{
// Don't crash trying to read more bits than we have available.
if (count << 3 > bits.available ()) {
return false;
}
byte[] readBytes = new byte[count];
for (int i = 0; i < count; i++) {
readBytes [i] = (byte)bits.readBits (8);
}
String encoding;
if (currentCharacterSetECI == null) {
// The spec isn't clear on this mode; see
// section 6.4.5: t does not say which encoding to assuming
// upon decoding. I have seen ISO-8859-1 used as well as
// Shift_JIS -- without anything like an ECI designator to
// give a hint.
encoding = StringUtils.guessEncoding (readBytes, hints);
} else {
encoding = currentCharacterSetECI.EncodingName;
}
try {
result.Append (Encoding.GetEncoding (encoding).GetString (readBytes, 0, readBytes.Length));
}
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
catch (ArgumentException)
{
try
{
// Silverlight only supports a limited number of character sets, trying fallback to UTF-8
result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
}
catch (Exception)
{
return false;
}
}
#endif
#if WindowsCE
catch (PlatformNotSupportedException)
{
try
{
// WindowsCE doesn't support all encodings. But it is device depended.
// So we try here the some different ones
if (encoding == "ISO-8859-1")
{
result.Append(Encoding.GetEncoding(1252).GetString(readBytes, 0, readBytes.Length));
}
else
{
result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
}
}
catch (Exception)
{
return false;
}
}
#endif
catch (Exception) {
return false;
}
byteSegments.Add (readBytes);
return true;
}
/// <summary>
/// See ISO 16022:2006, 5.2.9 and Annex B, B.2
/// </summary>
private static bool decodeBase256Segment(BitSource bits,
StringBuilder result,
IList<byte[]> byteSegments)
{
// Figure out how long the Base 256 Segment is.
int codewordPosition = 1 + bits.ByteOffset; // position is 1-indexed
int d1 = unrandomize255State(bits.readBits(8), codewordPosition++);
int count;
if (d1 == 0)
{ // Read the remainder of the symbol
count = bits.available() / 8;
}
else if (d1 < 250)
{
count = d1;
}
else
{
count = 250 * (d1 - 249) + unrandomize255State(bits.readBits(8), codewordPosition++);
}
// We're seeing NegativeArraySizeException errors from users.
if (count < 0)
{
return false;
}
byte[] bytes = new byte[count];
for (int i = 0; i < count; i++)
{
// Have seen this particular error in the wild, such as at
// http://www.bcgen.com/demo/IDAutomationStreamingDataMatrix.aspx?MODE=3&D=Fred&PFMT=3&PT=F&X=0.3&O=0&LM=0.2
if (bits.available() < 8)
{
return false;
}
bytes[i] = (byte)unrandomize255State(bits.readBits(8), codewordPosition++);
}
byteSegments.Add(bytes);
try
{
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || WINDOWS_PHONE80 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || WindowsCE || PORTABLE)
#if WindowsCE
result.Append(Encoding.GetEncoding(1252).GetString(bytes, 0, bytes.Length));
#else
result.Append(Encoding.GetEncoding("ISO-8859-1").GetString(bytes, 0, bytes.Length));
#endif
#else
result.Append(Encoding.GetEncoding("ISO-8859-1").GetString(bytes));
#endif
}
catch (Exception uee)
{
throw new InvalidOperationException("Platform does not support required encoding: " + uee);
}
return true;
}
internal static DecoderResult decode(byte[] bytes,
Version version,
ErrorCorrectionLevel ecLevel,
IDictionary<DecodeHintType, object> hints)
{
var bits = new BitSource(bytes);
var result = new StringBuilder(50);
var byteSegments = new List<byte[]>(1);
var symbolSequence = -1;
var parityData = -1;
try
{
// CharacterSetECI currentCharacterSetECI = null;
bool fc1InEffect = false;
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)
{
return null;
}
}
if (mode != Mode.TERMINATOR)
{
if (mode == Mode.FNC1_FIRST_POSITION || mode == 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 == Mode.STRUCTURED_APPEND)
{
if (bits.available() < 16)
{
return null;
}
// not really supported; but sequence number and parity is added later to the result metadata
// Read next 8 bits (symbol sequence #) and 8 bits (parity data), then continue
symbolSequence = bits.readBits(8);
parityData = bits.readBits(8);
}
else if (mode == Mode.ECI)
{
/*
// Count doesn't apply to ECI
int value = parseECIValue(bits);
currentCharacterSetECI = CharacterSetECI.getCharacterSetECIByValue(value);
if (currentCharacterSetECI == null)
{
return null;
}
* */
}
else
{
// First handle Hanzi mode which does not start with character count
if (mode == Mode.HANZI)
{
//chinese mode contains a sub set indicator right after mode indicator
int subset = bits.readBits(4);
int countHanzi = bits.readBits(mode.getCharacterCountBits(version));
if (subset == GB2312_SUBSET)
{
if (!decodeHanziSegment(bits, result, countHanzi))
return null;
}
}
else
{
// "Normal" QR code modes:
// How many characters will follow, encoded in this mode?
int count = bits.readBits(mode.getCharacterCountBits(version));
if (mode == Mode.NUMERIC)
{
if (!decodeNumericSegment(bits, result, count))
return null;
}
else if (mode == Mode.ALPHANUMERIC)
{
if (!decodeAlphanumericSegment(bits, result, count, fc1InEffect))
return null;
}
else if (mode == Mode.BYTE)
{
if (!decodeByteSegment(bits, result, count, byteSegments, hints))
return null;
}
else if (mode == Mode.KANJI)
{
if (!decodeKanjiSegment(bits, result, count))
return null;
}
else
{
return null;
}
}
}
}
} while (mode != Mode.TERMINATOR);
}
catch (ArgumentException)
{
// from readBits() calls
return null;
}
#if WindowsCE
var resultString = result.ToString().Replace("\n", "\r\n");
#else
var resultString = result.ToString().Replace("\r\n", "\n").Replace("\n", Environment.NewLine);
#endif
return new DecoderResult(bytes,
resultString,
byteSegments.Count == 0 ? null : byteSegments,
ecLevel == null ? null : ecLevel.ToString(),
symbolSequence, parityData);
}
/// <summary>
/// See specification GBT 18284-2000
/// </summary>
/// <param name="bits">The bits.</param>
/// <param name="result">The result.</param>
/// <param name="count">The count.</param>
/// <returns></returns>
private static bool decodeHanziSegment(BitSource bits,
StringBuilder result,
int count)
{
// Don't crash trying to read more bits than we have available.
if (count * 13 > bits.available())
{
return false;
}
// Each character will require 2 bytes. Read the characters as 2-byte pairs
// and decode as GB2312 afterwards
byte[] buffer = new byte[2 * count];
int offset = 0;
while (count > 0)
{
// Each 13 bits encodes a 2-byte character
int twoBytes = bits.readBits(13);
int assembledTwoBytes = ((twoBytes / 0x060) << 8) | (twoBytes % 0x060);
if (assembledTwoBytes < 0x003BF)
{
// In the 0xA1A1 to 0xAAFE range
assembledTwoBytes += 0x0A1A1;
}
else
{
// In the 0xB0A1 to 0xFAFE range
assembledTwoBytes += 0x0A6A1;
}
buffer[offset] = (byte)((assembledTwoBytes >> 8) & 0xFF);
buffer[offset + 1] = (byte)(assembledTwoBytes & 0xFF);
offset += 2;
count--;
}
try
{
result.Append(Encoding.GetEncoding(StringUtils.GB2312).GetString(buffer, 0, buffer.Length));
}
catch (Exception)
{
return false;
}
return true;
}