| static private lookAheadTest ( String msg, int startpos, int currentMode ) : int | ||
| msg | String | |
| startpos | int | |
| currentMode | int | |
| return | int | |
public void encode(EncoderContext context)
{
//step F
var buffer = new StringBuilder();
while (context.HasMoreCharacters)
{
char c = context.CurrentChar;
encodeChar(c, buffer);
context.Pos++;
int count = buffer.Length;
if (count >= 4)
{
context.writeCodewords(encodeToCodewords(buffer, 0));
buffer.Remove(0, 4);
int newMode = HighLevelEncoder.lookAheadTest(context.Message, context.Pos, EncodingMode);
if (newMode != EncodingMode)
{
context.signalEncoderChange(Encodation.ASCII);
break;
}
}
}
buffer.Append((char)31); //Unlatch
handleEOD(context, buffer);
}
override public void encode(EncoderContext context)
{
//step C
StringBuilder buffer = new StringBuilder();
while (context.HasMoreCharacters)
{
char c = context.CurrentChar;
context.Pos++;
encodeChar(c, buffer);
int count = buffer.Length;
if ((count % 3) == 0)
{
writeNextTriplet(context, buffer);
int newMode = HighLevelEncoder.lookAheadTest(context.Message, context.Pos, EncodingMode);
if (newMode != EncodingMode)
{
context.signalEncoderChange(newMode);
break;
}
}
}
handleEOD(context, buffer);
}
public override void encode(EncoderContext context)
{
//step C
var buffer = new StringBuilder();
int currentMode = EncodingMode;
while (context.HasMoreCharacters)
{
char c = context.CurrentChar;
context.Pos++;
encodeChar(c, buffer);
int count = buffer.Length;
if ((count % 3) == 0)
{
writeNextTriplet(context, buffer);
int newMode = HighLevelEncoder.lookAheadTest(context.Message, context.Pos, currentMode);
if (newMode != currentMode)
{
// Return to ASCII encodation, which will actually handle latch to new mode
context.signalEncoderChange((int)Encodation.ASCII);
break;
}
}
}
handleEOD(context, buffer);
}
public void encode(EncoderContext context)
{
var buffer = new StringBuilder();
buffer.Append('\u0000'); //Initialize length field
while (context.HasMoreCharacters)
{
char c = context.CurrentChar;
buffer.Append(c);
context.Pos++;
int newMode = HighLevelEncoder.lookAheadTest(context.Message, context.Pos, EncodingMode);
if (newMode != EncodingMode)
{
// Return to ASCII encodation, which will actually handle latch to new mode
context.signalEncoderChange((int)Encodation.ASCII);
break;
}
}
int dataCount = buffer.Length - 1;
const int lengthFieldSize = 1;
int currentSize = context.CodewordCount + dataCount + lengthFieldSize;
context.updateSymbolInfo(currentSize);
bool mustPad = (context.SymbolInfo.dataCapacity - currentSize) > 0;
if (context.HasMoreCharacters || mustPad)
{
if (dataCount <= 249)
{
buffer[0] = (char)dataCount;
}
else if (dataCount <= 1555)
{
buffer[0] = (char)((dataCount / 250) + 249);
buffer.Insert(1, new [] { (char)(dataCount % 250) });
}
else
{
throw new InvalidOperationException(
"Message length not in valid ranges: " + dataCount);
}
}
{
var c = buffer.Length;
for (int i = 0; i < c; i++)
{
context.writeCodeword(randomize255State(
buffer[i], context.CodewordCount + 1));
}
}
}
virtual public void encode(EncoderContext context)
{
//step C
var buffer = new StringBuilder();
while (context.HasMoreCharacters)
{
char c = context.CurrentChar;
context.Pos++;
int lastCharSize = encodeChar(c, buffer);
int unwritten = (buffer.Length / 3) * 2;
int curCodewordCount = context.CodewordCount + unwritten;
context.updateSymbolInfo(curCodewordCount);
int available = context.SymbolInfo.dataCapacity - curCodewordCount;
if (!context.HasMoreCharacters)
{
//Avoid having a single C40 value in the last triplet
var removed = new StringBuilder();
if ((buffer.Length % 3) == 2)
{
if (available < 2 || available > 2)
{
lastCharSize = backtrackOneCharacter(context, buffer, removed,
lastCharSize);
}
}
while ((buffer.Length % 3) == 1 &&
((lastCharSize <= 3 && available != 1) || lastCharSize > 3))
{
lastCharSize = backtrackOneCharacter(context, buffer, removed, lastCharSize);
}
break;
}
int count = buffer.Length;
if ((count % 3) == 0)
{
int newMode = HighLevelEncoder.lookAheadTest(context.Msg, context.Pos, EncodingMode);
if (newMode != EncodingMode)
{
context.signalEncoderChange(newMode);
break;
}
}
}
handleEOD(context, buffer);
}
public void encode(EncoderContext context)
{
//step B
int n = HighLevelEncoder.determineConsecutiveDigitCount(context.Message, context.Pos);
if (n >= 2)
{
context.writeCodeword(encodeASCIIDigits(context.Message[context.Pos],
context.Message[context.Pos + 1]));
context.Pos += 2;
}
else
{
char c = context.CurrentChar;
int newMode = HighLevelEncoder.lookAheadTest(context.Message, context.Pos, EncodingMode);
if (newMode != EncodingMode)
{
switch (newMode)
{
case Encodation.BASE256:
context.writeCodeword(HighLevelEncoder.LATCH_TO_BASE256);
context.signalEncoderChange(Encodation.BASE256);
return;
case Encodation.C40:
context.writeCodeword(HighLevelEncoder.LATCH_TO_C40);
context.signalEncoderChange(Encodation.C40);
return;
case Encodation.X12:
context.writeCodeword(HighLevelEncoder.LATCH_TO_ANSIX12);
context.signalEncoderChange(Encodation.X12);
break;
case Encodation.TEXT:
context.writeCodeword(HighLevelEncoder.LATCH_TO_TEXT);
context.signalEncoderChange(Encodation.TEXT);
break;
case Encodation.EDIFACT:
context.writeCodeword(HighLevelEncoder.LATCH_TO_EDIFACT);
context.signalEncoderChange(Encodation.EDIFACT);
break;
default:
throw new InvalidOperationException("Illegal mode: " + newMode);
}
}
else if (HighLevelEncoder.isExtendedASCII(c))
{
context.writeCodeword(HighLevelEncoder.UPPER_SHIFT);
context.writeCodeword((char)(c - 128 + 1));
context.Pos++;
}
else
{
context.writeCodeword((char)(c + 1));
context.Pos++;
}
}
}
protected virtual int CheckForMoreEffectiveEncodingMode(EncoderContext context)
{
return(HighLevelEncoder.lookAheadTest(context.Message, context.Pos, EncodingMode));
}