bool IsItRegisteredCommand(string command)
{
if (command.Length == 1)
{
return(false);
}
command = command.Substring(1);
if (TexFormulaParser.isCommandRegistered(command))
{
return(true);
}
if (TEXPreference.main.GetFontIndexByID(command) >= 0)
{
return(true);
}
return(false);
}
// This function can be called recursively
private string Parse(string original)
{
if (string.IsNullOrEmpty(original))
{
return(original);
}
original = original.Replace("\r", "");
var b = new StringBuilder();
int l = 0, e = 0, i = 0;
bool onRTL = IsFirstRecognizableCharIsRTL(original, 0), commonlyRTL = onRTL;
while (l < original.Length)
{
var c = original[l];
var p = l == 0 ? '\0' : original[l - 1];
var n = l == original.Length - 1 ? '\0' : original[l + 1];
bool ignored = IsIgnoredChar(c);
// If character is a new line
if (c == '\n')
{
if (e != l)
{
// This means something is left behind. Lets clear-em-up
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
e = l;
}
b.Append('\n');
e = ++l;
i = b.Length;
if (l < original.Length)
{
onRTL = commonlyRTL = IsFirstRecognizableCharIsRTL(original, l);
}
}
// If character is an opening brace
else if (c == '{' && p != '\\' && n != '}' && n != '\0')
{
if (e != l)
{
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
e = l;
}
var substring = TexFormulaParser.ReadGroup(original, ref l, '{', '}');
e = l;
var parsed = "{" + Parse(substring) + "}";
Insert(b, parsed, false, commonlyRTL, ref i);
}
// If character is a backslash (signals a command) (absolutely specific to TEXDraw behaviour)
else if (c == '\\' && p != '\\' && char.IsLetter(n))
{
if (e != l)
{
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
e = l;
}
l++;
var command = TexFormulaParser.LookForAWord(original, ref l);
var param1 = string.Empty;
var param2 = string.Empty;
if (l >= original.Length)
{
break;
}
else if (command.Contains("frac"))
{
param1 = "{" + Parse(TexFormulaParser.ReadGroup(original, ref l, '{', '}')) + "}";
param2 = "{" + Parse(TexFormulaParser.ReadGroup(original, ref l, '{', '}')) + "}";
}
else if (command == "rtl" || command == "ltr")
{
if (e != (l - 4))
{
Insert(b, original.Substring(e, (l - 4) - e), onRTL, commonlyRTL, ref i);
}
SkipWhiteSpace(original, ref l);
e = l;
onRTL = commonlyRTL = command == "rtl";
continue;
}
else if (TexFormulaParser.isCommandRegistered(command) || TEXPreference.main.GetFontIndexByID(command) >= 0)
{
if (original[l] == '[')
{
if (command == "root")
{
param1 = "[" + Parse(TexFormulaParser.ReadGroup(original, ref l, '[', ']')) + "]";
}
else
{
param1 = "[" + (TexFormulaParser.ReadGroup(original, ref l, '[', ']')) + "]";
}
}
if (l < original.Length && original[l] != '{' || !command.Contains("hold"))
{
param2 = "{" + Parse(TexFormulaParser.ReadGroup(original, ref l, '{', '}')) + "}";
}
}
var parsed = "\\" + command + param1 + param2;
Insert(b, parsed, false, commonlyRTL, ref i);
e = l;
}
// If character is a script sign (also specific to TEXDraw behaviour)
else if (c == '_' || c == '^' && p != '\\')
{
if (e != l)
{
Insert(b, original.Substring(e, l - e), onRTL, false, ref i);
e = l;
}
var iBackup = i;
while (c == '_' || c == '^')
{
l++;
var parsed = Parse(TexFormulaParser.ReadScriptGroup(original, ref l));
Insert(b, new string(c, 1) + parsed, onRTL, false, ref i);
c = l == original.Length ? '\0' : original[l];
}
e = l;
if (commonlyRTL)
{
i = iBackup;
}
}
// If character/space is different than current RTL mode
else if ((IsRTLChar(c) != onRTL && !ignored) ||
(ignored && l < original.Length - 1 && (onRTL ^ commonlyRTL) &&
((IsRTLChar(c = original[l + 1])) != onRTL)))
{
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
onRTL = IsRTLChar(c);
e = l++;
}
else
{
l++;
}
}
Insert(b, original.Substring(e), onRTL, commonlyRTL, ref i);
var result = b.ToString();
b.Length = 0;
return(result);
}