} // end constructor
private bool CommandTreeRootStateHandler(char commandChar)
{
switch (commandChar)
{
case 'm':
_SelectGraphicsRendition(m_state.FinishParsingParams());
return(true);
case '#':
m_state.CurrentCommandHandler = HashCommandStateHandler;
return(false);
default:
throw new NotSupportedException(String.Format("The command code '{0}' (0x{1:x}) is not supported.", commandChar, (int)commandChar));
}
}
} // end Write()
/// <summary>
/// Returns the index of the first character past the control sequence (which
/// could be past the end of the string, or could be the start of another
/// control sequence).
/// </summary>
private int _HandleControlSequence(string s, int escIndex)
{
m_state.Begin(); // we may actually be continuing...
char c;
int curIndex = escIndex;
while (++curIndex < s.Length)
{
c = s[curIndex];
if ((c >= '0') && (c <= '9'))
{
m_state.AccumParamDigit(((int)c) - 0x30);
continue;
}
else if (';' == c)
{
m_state.EnterParam();
continue;
}
else if (((c >= '@') && (c <= '~')) || (c == '#'))
{
if (_FindCommand(c, out Action <List <int> > command))
{
command(m_state.FinishParsingParams());
return(curIndex + 1);
}
}
else
{
// You're supposed to be able to have anonther character, like a space
// (0x20) before the command code character, but I'm not going to do that.
// TODO: Unfortunately, we can get into this scenario. Say somebody wrote a string to the
// output stream, and that string had control sequences. And say then somebody tried to process
// that string in a pipeline, for instance tried to find some property on it, that didn't
// exist, causing an error to be written, where the "target object" is the string... and stuff
// maybe gets truncated or ellipsis-ized... and then we're hosed. What should I do about this?
// Try to sanitize higher-level output? Seems daunting... Just reset state and ignore it? Hm.
m_state.Reset();
throw new ArgumentException(String.Format("Invalid command sequence character at position {0} (0x{1:x}).", curIndex, (int)c));
}
}
// Finished parsing the whole string--the control sequence must be broken across
// strings.
return(curIndex);
} // end _HandleControlSequence()