/// <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)
{
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)
{
FixNumbers(output, farsi);
}
}
/// <summary>
/// Handles the special Lam-Alef connection in the text.
/// </summary>
/// <param name="input"></param>
/// <param name="output"></param>
/// <param name="i">Index of Lam letter</param>
/// <returns><see langword="true" /> if special connection has been made.</returns>
private static bool HandleSpecialLam(FastStringBuilder input, FastStringBuilder output, int i)
{
bool isFixed;
switch (input.Get(i + 1))
{
case (char)GeneralLetters.AlefMaksoor:
output.Set(i, (char)0xFEF7);
isFixed = true;
break;
case (char)GeneralLetters.Alef:
output.Set(i, (char)0xFEF9);
isFixed = true;
break;
case (char)GeneralLetters.AlefHamza:
output.Set(i, (char)0xFEF5);
isFixed = true;
break;
case (char)GeneralLetters.AlefMad:
output.Set(i, (char)0xFEF3);
isFixed = true;
break;
default:
isFixed = false;
break;
}
if (isFixed)
{
output.Set(i + 1, (char)0xFFFF);
}
return isFixed;
}
/// <summary>
/// Removes tashkeel. Converts general RTL letters to isolated form. Also fixes Farsi and Arabic ی letter.
/// </summary>
/// <param name="text">Input to prepare</param>
/// <param name="farsi"></param>
/// <returns>Prepared input in char array</returns>
public static void FixYah(FastStringBuilder text, bool farsi)
{
for (int i = 0; i < text.Length; i++)
{
if (farsi && text.Get(i) == (int)GeneralLetters.Ya)
{
text.Set(i, (char)GeneralLetters.PersianYa);
}
else if (farsi == false && text.Get(i) == (int)GeneralLetters.PersianYa)
{
text.Set(i, (char)GeneralLetters.Ya);
}
}
}
public void SetValue_MakesIndependentCopies()
{
var builder1 = new FastStringBuilder("my holy moly text");
var builder2 = new FastStringBuilder(10);
builder2.SetValue(builder1);
builder1.Set(5, 'f');
Assert.AreNotEqual(builder1.ToString(), builder2.ToString());
}