/// <summary>
/// Removes tashkeel from text.
/// </summary>
public static void RemoveTashkeel(FastStringBuilder input)
{
TashkeelLocations.Clear();
int j = 0; // write index
for (int i = 0; i < input.Length; i++)
{
int curChar = input.Get(i);
if (Char32Utils.IsUnicode16Char(curChar) && TashkeelCharactersSet.Contains((char)curChar))
{
TashkeelLocations.Add(new TashkeelLocation((TashkeelCharacters)curChar, i));
}
else
{
input.Set(j, curChar);
j++;
}
}
input.Length = j;
}
/// <summary>
/// Fixes the flow of the text.
/// </summary>
public static void Fix(FastStringBuilder input, FastStringBuilder output, bool farsi, bool fixTextTags, bool preserveNumbers)
{
// Some texts like tags, English words and numbers need to be displayed in their original order.
// This list keeps the characters that their order should be reserved and streams reserved texts into final letters.
LtrTextHolder.Clear();
TagTextHolder.Clear();
for (int i = input.Length - 1; i >= 0; i--)
{
bool isInMiddle = i > 0 && i < input.Length - 1;
bool isAtBeginning = i == 0;
bool isAtEnd = i == input.Length - 1;
int characterAtThisIndex = input.Get(i);
int nextCharacter = default;
if (!isAtEnd)
{
nextCharacter = input.Get(i + 1);
}
int previousCharacter = default;
if (!isAtBeginning)
{
previousCharacter = input.Get(i - 1);
}
if (fixTextTags)
{
if (characterAtThisIndex == '>')
{
// We need to check if it is actually the beginning of a tag.
bool isValidTag = false;
int nextI = i;
TagTextHolder.Add(characterAtThisIndex);
for (int j = i - 1; j >= 0; j--)
{
var jChar = input.Get(j);
TagTextHolder.Add(jChar);
if (jChar == '<')
{
var jPlus1Char = input.Get(j + 1);
// Tags do not start with space
if (jPlus1Char == ' ')
{
break;
}
isValidTag = true;
nextI = j;
break;
}
}
if (isValidTag)
{
FlushBufferToOutput(LtrTextHolder, output);
FlushBufferToOutput(TagTextHolder, output);
i = nextI;
continue;
}
else
{
TagTextHolder.Clear();
}
}
}
if (Char32Utils.IsPunctuation(characterAtThisIndex) || Char32Utils.IsSymbol(characterAtThisIndex))
{
if (MirroredCharsSet.Contains((char)characterAtThisIndex))
{
// IsRTLCharacter returns false for null
bool isAfterRTLCharacter = Char32Utils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = Char32Utils.IsRTLCharacter(nextCharacter);
if (isAfterRTLCharacter || isBeforeRTLCharacter)
{
characterAtThisIndex = MirroredCharsMap[(char)characterAtThisIndex];
}
}
if (isInMiddle)
{
bool isAfterRTLCharacter = Char32Utils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = Char32Utils.IsRTLCharacter(nextCharacter);
bool isBeforeWhiteSpace = Char32Utils.IsWhiteSpace(nextCharacter);
bool isAfterWhiteSpace = Char32Utils.IsWhiteSpace(previousCharacter);
bool isUnderline = characterAtThisIndex == '_';
bool isSpecialPunctuation = characterAtThisIndex == '.' ||
characterAtThisIndex == '،' ||
characterAtThisIndex == '؛';
if (isBeforeRTLCharacter && isAfterRTLCharacter ||
isAfterWhiteSpace && isSpecialPunctuation ||
isBeforeWhiteSpace && isAfterRTLCharacter ||
isBeforeRTLCharacter && isAfterWhiteSpace ||
(isBeforeRTLCharacter || isAfterRTLCharacter) && isUnderline)
{
FlushBufferToOutput(LtrTextHolder, output);
output.Append(characterAtThisIndex);
}
else
{
LtrTextHolder.Add(characterAtThisIndex);
}
}
else if (isAtEnd)
{
LtrTextHolder.Add(characterAtThisIndex);
}
else if (isAtBeginning)
{
output.Append(characterAtThisIndex);
}
continue;
}
if (isInMiddle)
{
bool isAfterEnglishChar = Char32Utils.IsEnglishLetter(previousCharacter);
bool isBeforeEnglishChar = Char32Utils.IsEnglishLetter(nextCharacter);
bool isAfterNumber = Char32Utils.IsNumber(previousCharacter, preserveNumbers, farsi);
bool isBeforeNumber = Char32Utils.IsNumber(nextCharacter, preserveNumbers, farsi);
bool isAfterSymbol = Char32Utils.IsSymbol(previousCharacter);
bool isBeforeSymbol = Char32Utils.IsSymbol(nextCharacter);
// For cases where english words and farsi/arabic are mixed. This allows for using farsi/arabic, english and numbers in one sentence.
// If the space is between numbers,symbols or English words, keep the order
if (characterAtThisIndex == ' ' &&
(isBeforeEnglishChar || isBeforeNumber || isBeforeSymbol) &&
(isAfterEnglishChar || isAfterNumber || isAfterSymbol))
{
LtrTextHolder.Add(characterAtThisIndex);
continue;
}
}
if (Char32Utils.IsEnglishLetter(characterAtThisIndex) ||
Char32Utils.IsNumber(characterAtThisIndex, preserveNumbers, farsi))
{
LtrTextHolder.Add(characterAtThisIndex);
continue;
}
// handle surrogates
if (characterAtThisIndex >= (char)0xD800 &&
characterAtThisIndex <= (char)0xDBFF ||
characterAtThisIndex >= (char)0xDC00 && characterAtThisIndex <= (char)0xDFFF)
{
LtrTextHolder.Add(characterAtThisIndex);
continue;
}
FlushBufferToOutput(LtrTextHolder, output);
if (characterAtThisIndex != 0xFFFF &&
characterAtThisIndex != (int)SpecialCharacters.ZeroWidthNoJoiner)
{
output.Append(characterAtThisIndex);
}
}
FlushBufferToOutput(LtrTextHolder, output);
}