// 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";
}
}
// 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(const UChar* characters,
int length,
FontDescription::GenericFamilyType generic,
UChar32* charChecked,
UScriptCode* scriptChecked)
{
ASSERT(characters && characters[0] && length > 0);
UScriptCode script = USCRIPT_COMMON;
// Sometimes characters common to script (e.g. space) is at
// the beginning of a string so that we need to skip them
// to get a font required to render the string.
int i = 0;
UChar32 ucs4 = 0;
while (i < length && script == USCRIPT_COMMON || script == USCRIPT_INVALID_CODE) {
U16_NEXT(characters, i, length, ucs4);
UErrorCode err = U_ZERO_ERROR;
script = uscript_getScript(ucs4, &err);
// silently ignore the error
}
// 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 < ucs4 && ucs4 < 0xFF5F)
script = USCRIPT_HAN;
// There are a lot of characters in USCRIPT_COMMON that can be covered
// by fonts for scripts closely related to them. See
// http://unicode.org/cldr/utility/list-unicodeset.jsp?a=[:Script=Common:]
// FIXME: make this more efficient with a wider coverage
if (script == USCRIPT_COMMON || script == USCRIPT_INHERITED) {
UBlockCode block = ublock_getCode(ucs4);
switch (block) {
case UBLOCK_BASIC_LATIN:
script = USCRIPT_LATIN;
break;
case UBLOCK_CJK_SYMBOLS_AND_PUNCTUATION:
script = USCRIPT_HAN;
break;
case UBLOCK_HIRAGANA:
case UBLOCK_KATAKANA:
script = USCRIPT_HIRAGANA;
break;
case UBLOCK_ARABIC:
script = USCRIPT_ARABIC;
break;
case UBLOCK_GREEK:
script = USCRIPT_GREEK;
break;
case UBLOCK_DEVANAGARI:
// For Danda and Double Danda (U+0964, U+0965), use a Devanagari
// font for now although they're used by other scripts as well.
// Without a context, we can't do any better.
script = USCRIPT_DEVANAGARI;
break;
case UBLOCK_ARMENIAN:
script = USCRIPT_ARMENIAN;
break;
case UBLOCK_GEORGIAN:
script = USCRIPT_GEORGIAN;
break;
case UBLOCK_KANNADA:
script = USCRIPT_KANNADA;
break;
}
}
// Another lame work-around to cover non-BMP characters.
const UChar* family = getFontFamilyForScript(script, generic);
if (!family) {
int plane = ucs4 >> 16;
switch (plane) {
case 1:
family = L"code2001";
break;
case 2:
family = L"simsun-extb";
break;
default:
family = L"lucida sans unicode";
}
}
