UScriptCode getScript(int ucs4) {
UErrorCode err = U_ZERO_ERROR;
UScriptCode script = uscript_getScript(ucs4, &err);
// If script is invalid, common or inherited or there's an error,
// infer a script based on the unicode block of a character.
if (script <= USCRIPT_INHERITED || U_FAILURE(err))
script = getScriptBasedOnUnicodeBlock(ucs4);
return script;
}
// FIXME:
// - Handle 'Inherited', 'Common' and 'Unknown'
// (see http://www.unicode.org/reports/tr24/#Usage_Model )
// For 'Inherited' and 'Common', perhaps we need to
// accept another parameter indicating the previous family
// and just return it.
// - All the characters (or characters up to the point a single
// font can cover) need to be taken into account
const UChar* getFallbackFamily(UChar32 character,
FontDescription::GenericFamilyType generic,
UScriptCode contentScript,
const AtomicString& contentLocale,
UScriptCode* scriptChecked,
SkFontMgr* fontManager)
{
ASSERT(character);
ASSERT(fontManager);
const UChar* family = getFontBasedOnUnicodeBlock(character, fontManager);
if (family) {
if (scriptChecked)
*scriptChecked = USCRIPT_INVALID_CODE;
return family;
}
UScriptCode script = getScript(character);
// For the full-width ASCII characters (U+FF00 - U+FF5E), use the font for
// Han (determined in a locale-dependent way above). Full-width ASCII
// characters are rather widely used in Japanese and Chinese documents and
// they're fully covered by Chinese, Japanese and Korean fonts.
if (0xFF00 < character && character < 0xFF5F)
script = USCRIPT_HAN;
if (script == USCRIPT_COMMON)
script = getScriptBasedOnUnicodeBlock(character);
// For unified-Han scripts, try the lang attribute.
if (script == USCRIPT_HAN) {
if (isUnambiguousUnifiedHanScript(contentScript))
script = contentScript;
else
script = scriptCodeForUnifiedHanFromSubtags(contentLocale);
}
family = getFontFamilyForScript(script, generic, fontManager);
// Another lame work-around to cover non-BMP characters.
// If the font family for script is not found or the character is
// not in BMP (> U+FFFF), we resort to the hard-coded list of
// fallback fonts for now.
if (!family || character > 0xFFFF) {
int plane = character >> 16;
switch (plane) {
case 1:
family = L"code2001";
break;
case 2:
// Use a Traditional Chinese ExtB font if in Traditional Chinese locale.
// Otherwise, use a Simplified Chinese ExtB font. Windows Japanese
// fonts do support a small subset of ExtB (that are included in JIS X 0213),
// but its coverage is rather sparse.
// Eventually, this should be controlled by lang/xml:lang.
if (icu::Locale::getDefault() == icu::Locale::getTraditionalChinese())
family = L"pmingliu-extb";
else
family = L"simsun-extb";
break;
default:
family = L"lucida sans unicode";
}
}