private string ReadCodedStringInternal(BinaryStream stream, int?maxLength)
{
StringBuilder sb = new StringBuilder();
int count = 0;
bool saturnMode = false;
for (count = 0; (!maxLength.HasValue) ||
(maxLength.HasValue && count < maxLength);)
{
ContextString contextString;
ControlCode code = ProcessChar(stream, sb, saturnMode, ref count, out contextString);
if (code != null)
{
if (code.Flags.HasFlag(ControlCodeFlags.AlternateFont))
{
saturnMode = !saturnMode;
}
if (code.Flags.HasFlag(ControlCodeFlags.Terminate))
{
break;
}
}
}
// Advance the position past the end of the string if applicable
while (maxLength.HasValue && count++ < maxLength)
{
stream.ReadShort();
}
return(sb.ToString());
}
protected virtual ControlCode ProcessChar(BinaryStream stream, StringBuilder sb,
bool isSaturn, ref int count, out ContextString contextString)
{
contextString = null;
int chPosition = stream.Position;
short ch = stream.ReadShort();
count++;
ControlCode code = ControlCodes.FirstOrDefault(cc => cc.Code == ch);
var charLookup = isSaturn ? SaturnLookup : CharLookup;
if (code != null)
{
if (code.Code != -1)
{
sb.Append('[');
if (code.Tag != null)
{
sb.Append(code.Tag);
}
else
{
sb.Append(((ushort)ch).ToString("X4"));
}
for (int i = 0; i < code.Arguments; i++)
{
ch = stream.ReadShort();
count++;
sb.Append(' ');
sb.Append(((ushort)ch).ToString("X4"));
}
sb.Append(']');
}
}
else
{
if (charLookup.ContainsKey(ch))
{
contextString = charLookup[ch];
sb.Append(contextString.String);
}
else
{
sb.Append('[');
sb.Append(((ushort)ch).ToString("X4"));
sb.Append(']');
//logger.Debug($"Unrecognized character: [{ch:X4}] at 0x{chPosition:X}");
}
}
return(code);
}