// Wrappers for TextUtil methods
public static bool IsRTLCharacter(int ch)
{
if (!IsUnicode16Char(ch))
{
return(false);
}
return(TextUtils.IsRTLCharacter((char)ch));
}
/// <summary>
/// Is the letter at provided index a finishing letter?
/// </summary>
/// <returns><see langword="true" /> if the letter is a finishing letter</returns>
private static bool IsFinishingLetter(FastStringBuilder letters, int index)
{
char currentIndexLetter = letters.Get(index);
char previousIndexLetter = default;
if (index != 0)
{
previousIndexLetter = letters.Get(index - 1);
}
bool isPreviousLetterConnectable = index != 0 &&
previousIndexLetter != ' ' &&
previousIndexLetter != (int)GeneralLetters.Dal &&
previousIndexLetter != (int)GeneralLetters.Thal &&
previousIndexLetter != (int)GeneralLetters.Ra2 &&
previousIndexLetter != (int)GeneralLetters.Zeen &&
previousIndexLetter != (int)GeneralLetters.PersianZe &&
previousIndexLetter != (int)GeneralLetters.Waw &&
previousIndexLetter != (int)GeneralLetters.Alef &&
previousIndexLetter != (int)GeneralLetters.AlefMad &&
previousIndexLetter != (int)GeneralLetters.AlefHamza &&
previousIndexLetter != (int)GeneralLetters.AlefMaksoor &&
previousIndexLetter != (int)GeneralLetters.WawHamza &&
previousIndexLetter != (int)GeneralLetters.Hamza &&
previousIndexLetter != (int)GeneralLetters.ZeroWidthNoJoiner &&
previousIndexLetter != (int)IsolatedLetters.Dal &&
previousIndexLetter != (int)IsolatedLetters.Thal &&
previousIndexLetter != (int)IsolatedLetters.Ra2 &&
previousIndexLetter != (int)IsolatedLetters.Zeen &&
previousIndexLetter != (int)IsolatedLetters.PersianZe &&
previousIndexLetter != (int)IsolatedLetters.Waw &&
previousIndexLetter != (int)IsolatedLetters.Alef &&
previousIndexLetter != (int)IsolatedLetters.AlefMad &&
previousIndexLetter != (int)IsolatedLetters.AlefHamza &&
previousIndexLetter != (int)IsolatedLetters.AlefMaksoor &&
previousIndexLetter != (int)IsolatedLetters.WawHamza &&
previousIndexLetter != (int)IsolatedLetters.Hamza &&
TextUtils.IsRTLCharacter(previousIndexLetter);
bool canThisLetterBeFinishing = currentIndexLetter != ' ' &&
currentIndexLetter != (int)GeneralLetters.ZeroWidthNoJoiner &&
currentIndexLetter != (int)GeneralLetters.Hamza;
return(isPreviousLetterConnectable && canThisLetterBeFinishing);
}
/// <summary>
/// Converts English numbers that are outside tags to Persian or Arabic numbers.
/// </summary>
/// <param name="text"></param>
/// <param name="farsi"></param>
/// <returns>Text with converted numbers</returns>
public static void FixNumbersOutsideOfTags(FastStringBuilder text, bool farsi)
{
var englishDigits = new HashSet <char>(EnglishToFarsiNumberMap.Keys);
for (int i = 0; i < text.Length; i++)
{
var iChar = text.Get(i);
// skip valid tags
if (iChar == '<')
{
bool sawValidTag = false;
for (int j = i + 1; j < text.Length; j++)
{
char jChar = text.Get(j);
if (jChar == ' ' || TextUtils.IsRTLCharacter(jChar))
{
break;
}
else if (jChar == '>')
{
i = j;
sawValidTag = true;
break;
}
}
if (sawValidTag)
{
continue;
}
}
if (englishDigits.Contains(iChar))
{
text.Set(i, farsi ? EnglishToFarsiNumberMap[iChar] : EnglishToHinduNumberMap[iChar]);
}
}
}
/// <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;
char characterAtThisIndex = input.Get(i);
char nextCharacter = default;
if (!isAtEnd)
{
nextCharacter = input.Get(i + 1);
}
char 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);
// Tags do not have space inside
if (jChar == ' ')
{
break;
}
// Tags do not have RTL characters inside
if (TextUtils.IsRTLCharacter(jChar))
{
break;
}
TagTextHolder.Add(jChar);
if (jChar == '<')
{
isValidTag = true;
nextI = j;
break;
}
}
if (isValidTag)
{
FlushBufferToOutput(LtrTextHolder, output);
FlushBufferToOutput(TagTextHolder, output);
i = nextI;
continue;
}
else
{
TagTextHolder.Clear();
}
}
}
if (char.IsPunctuation(characterAtThisIndex) || char.IsSymbol(characterAtThisIndex))
{
if (MirroredCharsSet.Contains(characterAtThisIndex))
{
// IsRTLCharacter returns false for null
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isAfterRTLCharacter || isBeforeRTLCharacter)
{
characterAtThisIndex = MirroredCharsMap[characterAtThisIndex];
}
}
if (isInMiddle)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
bool isBeforeWhiteSpace = char.IsWhiteSpace(nextCharacter);
bool isAfterWhiteSpace = char.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 = TextUtils.IsEnglishLetter(previousCharacter);
bool isBeforeEnglishChar = TextUtils.IsEnglishLetter(nextCharacter);
bool isAfterNumber = TextUtils.IsNumber(previousCharacter, preserveNumbers, farsi);
bool isBeforeNumber = TextUtils.IsNumber(nextCharacter, preserveNumbers, farsi);
bool isAfterSymbol = char.IsSymbol(previousCharacter);
bool isBeforeSymbol = char.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 (TextUtils.IsEnglishLetter(characterAtThisIndex) ||
TextUtils.IsNumber(characterAtThisIndex, preserveNumbers, farsi))
{
LtrTextHolder.Add(characterAtThisIndex);
continue;
}
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)GeneralLetters.ZeroWidthNoJoiner)
{
output.Append(characterAtThisIndex);
}
}
FlushBufferToOutput(LtrTextHolder, output);
}
public static void FindTag(
FastStringBuilder str,
int start,
out int tagStart,
out int tagEnd,
out int tagType,
out int hashCode)
{
for (int i = start; i < str.Length;)
{
if (str.Get(i) != '<')
{
i++;
continue;
}
bool calculateHashCode = true;
hashCode = 0;
for (int j = i + 1; j < str.Length; j++)
{
char jChar = str.Get(j);
if (calculateHashCode)
{
if (char.IsLetter(jChar))
{
unchecked
{
if (hashCode == 0)
{
hashCode = jChar.GetHashCode();
}
else
{
hashCode = (hashCode * 397) ^ jChar.GetHashCode();
}
}
}
else if (hashCode != 0)
{
// We have computed the hash code. Now we reached a non letter character. We need to stop
calculateHashCode = false;
}
}
// Rich text tag cannot contain RTL chars
if (TextUtils.IsRTLCharacter(jChar))
{
break;
}
if (jChar == '>')
{
// Check if the tag is closing, opening or self contained
tagStart = i;
tagEnd = j + 1;
if (str.Get(j - 1) == '/')
{
// This is self contained.
tagType = 3;
return;
}
if (str.Get(i + 1) == '/')
{
// This is closing
tagType = 2;
return;
}
tagType = 1;
return;
}
}
i++;
}
tagStart = 0;
tagEnd = 0;
tagType = 0;
hashCode = 0;
}
/// <summary>
/// Fixes the shape of letters based on their position.
/// </summary>
/// <param name="input"></param>
/// <param name="output"></param>
/// <param name="preserveNumbers"></param>
/// <param name="farsi"></param>
/// <returns></returns>
public static void Fix(FastStringBuilder input, FastStringBuilder output, bool preserveNumbers, bool farsi, bool fixTextTags)
{
FixYah(input, farsi);
output.SetValue(input);
for (int i = 0; i < input.Length; i++)
{
bool skipNext = false;
char iChar = input.Get(i);
// For special Lam Letter connections.
if (iChar == (char)GeneralLetters.Lam)
{
if (i < input.Length - 1)
{
skipNext = HandleSpecialLam(input, output, i);
if (skipNext)
{
iChar = output.Get(i);
}
}
}
// We don't want to fix tatweel or zwnj character
if (iChar == (int)GeneralLetters.ArabicTatweel ||
iChar == (int)GeneralLetters.ZeroWidthNoJoiner)
{
continue;
}
if (TextUtils.IsRTLCharacter(iChar))
{
char converted = GlyphTable.Convert(iChar);
if (IsMiddleLetter(input, i))
{
output.Set(i, (char)(converted + 3));
}
else if (IsFinishingLetter(input, i))
{
output.Set(i, (char)(converted + 1));
}
else if (IsLeadingLetter(input, i))
{
output.Set(i, (char)(converted + 2));
}
}
// If this letter as Lam and special Lam-Alef connection was made, We want to skip the Alef
// (Lam-Alef occupies 1 space)
if (skipNext)
{
i++;
}
}
if (!preserveNumbers)
{
if (fixTextTags)
{
FixNumbersOutsideOfTags(output, farsi);
}
else
{
FixNumbers(output, farsi);
}
}
}
/// <summary>
/// Is the letter at provided index a middle letter?
/// </summary>
/// <returns><see langword="true" /> if the letter is a middle letter</returns>
private static bool IsMiddleLetter(FastStringBuilder letters, int index)
{
var currentIndexLetter = letters.Get(index);
char previousIndexLetter = default;
if (index != 0)
{
previousIndexLetter = letters.Get(index - 1);
}
char nextIndexLetter = default;
if (index < letters.Length - 1)
{
nextIndexLetter = letters.Get(index + 1);
}
bool middleLetterCheck = index != 0 &&
currentIndexLetter != (int)GeneralLetters.Alef &&
currentIndexLetter != (int)GeneralLetters.Dal &&
currentIndexLetter != (int)GeneralLetters.Thal &&
currentIndexLetter != (int)GeneralLetters.Ra2 &&
currentIndexLetter != (int)GeneralLetters.Zeen &&
currentIndexLetter != (int)GeneralLetters.PersianZe &&
currentIndexLetter != (int)GeneralLetters.Waw &&
currentIndexLetter != (int)GeneralLetters.AlefMad &&
currentIndexLetter != (int)GeneralLetters.AlefHamza &&
currentIndexLetter != (int)GeneralLetters.AlefMaksoor &&
currentIndexLetter != (int)GeneralLetters.WawHamza &&
currentIndexLetter != (int)GeneralLetters.ZeroWidthNoJoiner &&
currentIndexLetter != (int)GeneralLetters.Hamza;
bool previousLetterCheck = index != 0 &&
previousIndexLetter != (int)GeneralLetters.Alef &&
previousIndexLetter != (int)GeneralLetters.Dal &&
previousIndexLetter != (int)GeneralLetters.Thal &&
previousIndexLetter != (int)GeneralLetters.Ra2 &&
previousIndexLetter != (int)GeneralLetters.Zeen &&
previousIndexLetter != (int)GeneralLetters.PersianZe &&
previousIndexLetter != (int)GeneralLetters.Waw &&
previousIndexLetter != (int)GeneralLetters.AlefMad &&
previousIndexLetter != (int)GeneralLetters.AlefHamza &&
previousIndexLetter != (int)GeneralLetters.AlefMaksoor &&
previousIndexLetter != (int)GeneralLetters.WawHamza &&
previousIndexLetter != (int)GeneralLetters.Hamza &&
previousIndexLetter !=
(int)GeneralLetters.ZeroWidthNoJoiner &&
previousIndexLetter != (int)IsolatedLetters.Alef &&
previousIndexLetter != (int)IsolatedLetters.Dal &&
previousIndexLetter != (int)IsolatedLetters.Thal &&
previousIndexLetter != (int)IsolatedLetters.Ra2 &&
previousIndexLetter != (int)IsolatedLetters.Zeen &&
previousIndexLetter != (int)IsolatedLetters.PersianZe &&
previousIndexLetter != (int)IsolatedLetters.Waw &&
previousIndexLetter != (int)IsolatedLetters.AlefMad &&
previousIndexLetter != (int)IsolatedLetters.AlefHamza &&
previousIndexLetter != (int)IsolatedLetters.AlefMaksoor &&
previousIndexLetter != (int)IsolatedLetters.WawHamza &&
previousIndexLetter != (int)IsolatedLetters.Hamza &&
TextUtils.IsRTLCharacter(previousIndexLetter);
bool nextLetterCheck = index < letters.Length - 1 &&
TextUtils.IsRTLCharacter(nextIndexLetter) &&
nextIndexLetter != (int)GeneralLetters.ZeroWidthNoJoiner &&
nextIndexLetter != (int)GeneralLetters.Hamza &&
nextIndexLetter != (int)IsolatedLetters.Hamza;
return(nextLetterCheck && previousLetterCheck && middleLetterCheck);
}
/// <summary>
/// Is the letter at provided index a leading letter?
/// </summary>
/// <returns><see langword="true" /> if the letter is a leading letter</returns>
private static bool IsLeadingLetter(FastStringBuilder letters, int index)
{
var currentIndexLetter = letters.Get(index);
char previousIndexLetter = default;
if (index != 0)
{
previousIndexLetter = letters.Get(index - 1);
}
char nextIndexLetter = default;
if (index < letters.Length - 1)
{
nextIndexLetter = letters.Get(index + 1);
}
bool isPreviousLetterNonConnectable = index == 0 ||
!TextUtils.IsRTLCharacter(previousIndexLetter) ||
previousIndexLetter == (int)GeneralLetters.Alef ||
previousIndexLetter == (int)GeneralLetters.Dal ||
previousIndexLetter == (int)GeneralLetters.Thal ||
previousIndexLetter == (int)GeneralLetters.Ra2 ||
previousIndexLetter == (int)GeneralLetters.Zeen ||
previousIndexLetter == (int)GeneralLetters.PersianZe ||
previousIndexLetter == (int)GeneralLetters.Waw ||
previousIndexLetter == (int)GeneralLetters.AlefMad ||
previousIndexLetter ==
(int)GeneralLetters.AlefHamza ||
previousIndexLetter ==
(int)GeneralLetters.Hamza ||
previousIndexLetter ==
(int)GeneralLetters.AlefMaksoor ||
previousIndexLetter ==
(int)GeneralLetters.ZeroWidthNoJoiner ||
previousIndexLetter ==
(int)GeneralLetters.WawHamza ||
previousIndexLetter ==
(int)IsolatedLetters.Alef ||
previousIndexLetter == (int)IsolatedLetters.Dal ||
previousIndexLetter ==
(int)IsolatedLetters.Thal ||
previousIndexLetter == (int)IsolatedLetters.Ra2 ||
previousIndexLetter ==
(int)IsolatedLetters.Zeen ||
previousIndexLetter ==
(int)IsolatedLetters.PersianZe ||
previousIndexLetter == (int)IsolatedLetters.Waw ||
previousIndexLetter ==
(int)IsolatedLetters.AlefMad ||
previousIndexLetter ==
(int)IsolatedLetters.AlefHamza ||
previousIndexLetter ==
(int)IsolatedLetters.Hamza ||
previousIndexLetter ==
(int)IsolatedLetters.AlefMaksoor;
bool canThisLetterBeLeading = currentIndexLetter != ' ' &&
currentIndexLetter != (int)GeneralLetters.Dal &&
currentIndexLetter != (int)GeneralLetters.Thal &&
currentIndexLetter != (int)GeneralLetters.Ra2 &&
currentIndexLetter != (int)GeneralLetters.Zeen &&
currentIndexLetter != (int)GeneralLetters.PersianZe &&
currentIndexLetter != (int)GeneralLetters.Alef &&
currentIndexLetter != (int)GeneralLetters.AlefHamza &&
currentIndexLetter != (int)GeneralLetters.AlefMaksoor &&
currentIndexLetter != (int)GeneralLetters.AlefMad &&
currentIndexLetter != (int)GeneralLetters.WawHamza &&
currentIndexLetter != (int)GeneralLetters.Waw &&
currentIndexLetter !=
(int)GeneralLetters.ZeroWidthNoJoiner &&
currentIndexLetter != (int)GeneralLetters.Hamza;
bool isNextLetterConnectable = index < letters.Length - 1 &&
TextUtils.IsRTLCharacter(nextIndexLetter) &&
nextIndexLetter != (int)GeneralLetters.Hamza &&
nextIndexLetter !=
(int)GeneralLetters.ZeroWidthNoJoiner;
return(isPreviousLetterNonConnectable &&
canThisLetterBeLeading &&
isNextLetterConnectable);
}
/// <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();
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;
char characterAtThisIndex = input.Get(i);
char nextCharacter = default;
if (!isAtEnd)
{
nextCharacter = input.Get(i + 1);
}
char previousCharacter = default;
if (!isAtBeginning)
{
previousCharacter = input.Get(i - 1);
}
if (char.IsPunctuation(characterAtThisIndex) || char.IsSymbol(characterAtThisIndex))
{
if (fixTextTags)
{
if (characterAtThisIndex == '>')
{
// We need to check if it is actually the beginning of a tag.
bool isValidTag = false;
// If > is at the end of the text (At beginning of the array), it can't be a tag
if (isAtEnd == false)
{
for (int j = i - 1; j >= 0; j--)
{
// Tags do not have space inside
if (input.Get(j) == ' ')
{
break;
}
// Tags do not have RTL characters inside
if (TextUtils.IsRTLCharacter(input.Get(j)))
{
break;
}
if (input.Get(j) == '<')
{
isValidTag = true;
break;
}
}
}
if (LtrTextHolder.Count > 0 && isValidTag)
{
for (int j = 0; j < LtrTextHolder.Count; j++)
{
output.Append(LtrTextHolder[LtrTextHolder.Count - 1 - j]);
}
LtrTextHolder.Clear();
}
}
}
if (characterAtThisIndex == ')')
{
if (isInMiddle)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isAfterRTLCharacter || isBeforeRTLCharacter)
{
characterAtThisIndex = '(';
}
}
else if (isAtEnd)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
if (isAfterRTLCharacter)
{
characterAtThisIndex = '(';
}
}
else if (isAtBeginning)
{
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isBeforeRTLCharacter)
{
characterAtThisIndex = '(';
}
}
}
else if (characterAtThisIndex == '(')
{
if (isInMiddle)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isAfterRTLCharacter || isBeforeRTLCharacter)
{
characterAtThisIndex = ')';
}
}
else if (isAtEnd)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
if (isAfterRTLCharacter)
{
characterAtThisIndex = ')';
}
}
else if (isAtBeginning)
{
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isBeforeRTLCharacter)
{
characterAtThisIndex = ')';
}
}
}
else if (characterAtThisIndex == '«')
{
if (isInMiddle)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
if (isAfterRTLCharacter || isBeforeRTLCharacter)
{
characterAtThisIndex = '»';
}
}
else if (isAtEnd)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isAfterRTLCharacter)
{
characterAtThisIndex = '»';
}
}
else if (isAtBeginning)
{
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
if (isBeforeRTLCharacter)
{
characterAtThisIndex = '»';
}
}
}
else if (characterAtThisIndex == '»')
{
if (isInMiddle)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
if (isAfterRTLCharacter || isBeforeRTLCharacter)
{
characterAtThisIndex = '«';
}
}
else if (isAtEnd)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
if (isAfterRTLCharacter)
{
characterAtThisIndex = '«';
}
}
else if (isAtBeginning)
{
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
if (isBeforeRTLCharacter)
{
characterAtThisIndex = '«';
}
}
}
if (isInMiddle)
{
bool isAfterRTLCharacter = TextUtils.IsRTLCharacter(previousCharacter);
bool isBeforeRTLCharacter = TextUtils.IsRTLCharacter(nextCharacter);
bool isBeforeWhiteSpace = char.IsWhiteSpace(nextCharacter);
bool isAfterWhiteSpace = char.IsWhiteSpace(previousCharacter);
bool isUnderline = characterAtThisIndex == '_';
bool isSpecialPunctuation = characterAtThisIndex == '.' ||
characterAtThisIndex == '،' ||
characterAtThisIndex == '؛';
if (isBeforeRTLCharacter && isAfterRTLCharacter ||
isAfterWhiteSpace && isSpecialPunctuation ||
isBeforeWhiteSpace && isAfterRTLCharacter ||
isBeforeRTLCharacter && isAfterWhiteSpace ||
(isBeforeRTLCharacter || isAfterRTLCharacter) && isUnderline)
{
if (LtrTextHolder.Count > 0)
{
for (int j = 0; j < LtrTextHolder.Count; j++)
{
output.Append(LtrTextHolder[LtrTextHolder.Count - 1 - j]);
}
LtrTextHolder.Clear();
}
output.Append(characterAtThisIndex);
}
else
{
LtrTextHolder.Add(characterAtThisIndex);
}
}
else if (isAtEnd)
{
LtrTextHolder.Add(characterAtThisIndex);
}
else if (isAtBeginning)
{
output.Append(characterAtThisIndex);
}
if (fixTextTags)
{
if (characterAtThisIndex == '<')
{
bool valid = false;
if (isAtBeginning == false)
{
for (int j = i + 1; j < input.Length; j++)
{
// Tags do not have space inside
if (input.Get(j) == ' ')
{
break;
}
// Tags do not have RTL characters inside
if (TextUtils.IsRTLCharacter(input.Get(j)))
{
break;
}
if (input.Get(j) == '>')
{
valid = true;
break;
}
}
}
if (LtrTextHolder.Count > 0 && valid)
{
for (int j = 0; j < LtrTextHolder.Count; j++)
{
output.Append(LtrTextHolder[LtrTextHolder.Count - 1 - j]);
}
LtrTextHolder.Clear();
}
}
}
continue;
}
if (isInMiddle)
{
bool isAfterEnglishChar = TextUtils.IsEnglishLetter(previousCharacter);
bool isBeforeEnglishChar = TextUtils.IsEnglishLetter(nextCharacter);
bool isAfterNumber = TextUtils.IsNumber(previousCharacter, preserveNumbers, farsi);
bool isBeforeNumber = TextUtils.IsNumber(nextCharacter, preserveNumbers, farsi);
bool isAfterSymbol = char.IsSymbol(previousCharacter);
bool isBeforeSymbol = char.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 (TextUtils.IsEnglishLetter(characterAtThisIndex) ||
TextUtils.IsNumber(characterAtThisIndex, preserveNumbers, farsi))
{
LtrTextHolder.Add(characterAtThisIndex);
continue;
}
if (characterAtThisIndex >= (char)0xD800 &&
characterAtThisIndex <= (char)0xDBFF ||
characterAtThisIndex >= (char)0xDC00 && characterAtThisIndex <= (char)0xDFFF)
{
LtrTextHolder.Add(characterAtThisIndex);
continue;
}
if (LtrTextHolder.Count > 0)
{
for (int j = 0; j < LtrTextHolder.Count; j++)
{
output.Append(LtrTextHolder[LtrTextHolder.Count - 1 - j]);
}
LtrTextHolder.Clear();
}
if (characterAtThisIndex != 0xFFFF &&
characterAtThisIndex != (int)GeneralLetters.ZeroWidthNoJoiner)
{
output.Append(characterAtThisIndex);
}
}
if (LtrTextHolder.Count > 0)
{
for (int j = 0; j < LtrTextHolder.Count; j++)
{
output.Append(LtrTextHolder[LtrTextHolder.Count - 1 - j]);
}
LtrTextHolder.Clear();
}
}
