/// ------------------------------------------------------------------------------------
/// <summary>
/// Determines whether the specified character is a mark (either as defined by the
/// character property engine or as overridden by the language definition.
/// </summary>
/// <param name="chr">The character.</param>
/// <param name="langDef">The language definition (can be null).</param>
/// <param name="cpe">The character property engine.</param>
/// ------------------------------------------------------------------------------------
private static bool IsMark(char chr, LanguageDefinition langDef, ILgCharacterPropertyEngine cpe)
{
string category = (langDef == null) ? null : langDef.GetOverrideCharCategory(chr);
return ((category == null && cpe.get_IsMark(chr)) || (category != null && category[0] == 'M'));
}
/// ------------------------------------------------------------------------------------
/// <summary>
/// Update the characters in the Private Use Area.
/// </summary>
/// ------------------------------------------------------------------------------------
public static void UpdatePUACollection(LanguageDefinition langDef, List<string> chars)
{
List<PUACharacter> customPuaCharacters = GetDefinedCustomPUACharsFromICU();
// Remove any PUA characters that are no longer in the character list. If there
// are any new PUA characters in the valid characters list, they
// will be added to this collection in IsCodePointDefined().
int codePoint;
string data;
for (int i = langDef.PuaDefinitionCount - 1; i >= 0; i--)
{
langDef.GetPuaDefinition(i, out codePoint, out data);
char character = (char)new PUACharacter(codePoint).Character;
string category = langDef.GetOverrideCharCategory(character);
if (!chars.Contains(character.ToString()) && (category == null || category[0] != 'M'))
{
langDef.RemovePuaDefinition(new CharDef(codePoint, data));
}
}
// Now make sure all the custom PUA characters specified in the valid characters
// list are also added to the language definition's PUA collection.
foreach (string chr in chars)
{
// Go through the codepoints in the character.
foreach (char c in chr)
UpdateLangDefPUACollection((int)c, langDef, customPuaCharacters);
}
}
/// ------------------------------------------------------------------------------------
/// <summary>
/// Finds the first base character/combining diacritic combination and removes any
/// remaining characters.
/// </summary>
/// <param name="origChars">The original string of characters.</param>
/// <param name="langDef">The language definition which could override some of the
/// properties defined by the <paramref name="cpe"/>.</param>
/// <param name="cpe">The character property engine.</param>
/// ------------------------------------------------------------------------------------
public static string ValidateCharacterSequence(string origChars,
LanguageDefinition langDef, ILgCharacterPropertyEngine cpe)
{
// Allow spaces (Zs), hard line breaks (Zl), and other formatting characters (Cf) in
// isolation only.
if (origChars.Length == 1)
{
string category = (langDef == null) ? null : langDef.GetOverrideCharCategory(origChars[0]);
switch (category)
{
case "Zl":
case "Zs":
case "Cf": return origChars;
}
if (category == null &&
(cpe.get_GeneralCategory(origChars[0]) == LgGeneralCharCategory.kccZl ||
cpe.get_GeneralCategory(origChars[0]) == LgGeneralCharCategory.kccZs ||
cpe.get_GeneralCategory(origChars[0]) == LgGeneralCharCategory.kccCf))
{
return origChars;
}
}
StringBuilder newChars = new StringBuilder();
bool baseFound = false;
bool fPrecedingCharWasMark = false;
// Extract first base character and any following diacritics
for (int ich = 0; ich < origChars.Length; ich++ )
{
char chr = origChars[ich];
if (!baseFound)
{
string category = (langDef == null) ? null : langDef.GetOverrideCharCategory(chr);
if (category == null)
{
// If this is not a valid base character, keep looking.
if (!cpe.get_IsLetter(chr) && !cpe.get_IsNumber(chr) &&
cpe.get_GeneralCategory(chr) != LgGeneralCharCategory.kccCo &&
!cpe.get_IsPunctuation(chr) && !cpe.get_IsSymbol(chr))
continue;
}
else
{
// If this is not a valid base character, keep looking.
if (category[0] != 'L' && category[0] != 'N' &&
category != "Co" && category[0] != 'P' && category[0] != 'S')
continue;
}
baseFound = true;
}
else
{
// If this is not a diacritic or a ZWJ or ZWNJ between diacritics,
// discard the rest of the string.
if (IsMark(chr, langDef, cpe))
{
fPrecedingCharWasMark = true;
}
else if ((chr == '\u200C' || chr == '\u200D') && fPrecedingCharWasMark &&
origChars.Length > ich + 1 && IsMark(origChars[ich + 1], langDef, cpe))
{
fPrecedingCharWasMark = false;
}
else
{
// This handles special situations like Korean, where multiple base letters
// (representing phonemes) can compose into a single base letter (representing a
// syllable).
string composed = Icu.Normalize(origChars, Icu.UNormalizationMode.UNORM_NFKC);
if (composed.Length == 1)
return composed;
break;
}
}
if (baseFound)
newChars.Append(chr);
}
return newChars.ToString();
}
