Fix sorting of fallback fonts based on writing systems

This rewrites 243f4b2a8c
in a more complete and optimized manner

Task-number: QTBUG-81924
Change-Id: I52105a9ede07ce350fad3d50277dd631df371f06
Reviewed-by: Hikaru Terazono (3c1u) <3c1u@vulpesgames.tokyo>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
This commit is contained in:
Konstantin Ritt 2020-02-12 06:50:11 +03:00
parent 540bd6cf20
commit 181bece09a

View File

@ -597,6 +597,25 @@ Q_GUI_EXPORT int qt_script_for_writing_system(QFontDatabase::WritingSystem writi
}
/*!
\internal
Tests if the given family \a family supports writing system \a writingSystem,
including the special case for Han script mapping to several subsequent writing systems
*/
static bool familySupportsWritingSystem(QtFontFamily *family, size_t writingSystem)
{
Q_ASSERT(family != nullptr);
Q_ASSERT(writingSystem != QFontDatabase::Any && writingSystem < QFontDatabase::WritingSystemsCount);
size_t ws = writingSystem;
do {
if ((family->writingSystems[ws] & QtFontFamily::Supported) != 0)
return true;
} while (writingSystem >= QFontDatabase::SimplifiedChinese && writingSystem <= QFontDatabase::Japanese && ++ws <= QFontDatabase::Japanese);
return false;
}
/*!
@ -826,19 +845,7 @@ QStringList QPlatformFontDatabase::fallbacksForFamily(const QString &family, QFo
f->ensurePopulated();
size_t otherWritingSystem = writingSystem;
while (writingSystem > QFontDatabase::Any && f->writingSystems[otherWritingSystem] != QtFontFamily::Supported) {
otherWritingSystem = std::find(scriptForWritingSystem + (otherWritingSystem + 1),
scriptForWritingSystem + QFontDatabase::WritingSystemsCount,
script) - scriptForWritingSystem;
if (otherWritingSystem >= QFontDatabase::WritingSystemsCount) {
break;
}
}
if (otherWritingSystem >= QFontDatabase::WritingSystemsCount)
if (writingSystem != QFontDatabase::Any && !familySupportsWritingSystem(f, writingSystem))
continue;
for (int j = 0; j < f->count; ++j) {
@ -1283,7 +1290,7 @@ static int match(int script, const QFontDef &request,
test.family->ensurePopulated();
// Check if family is supported in the script we want
if (writingSystem != QFontDatabase::Any && !(test.family->writingSystems[writingSystem] & QtFontFamily::Supported))
if (writingSystem != QFontDatabase::Any && !familySupportsWritingSystem(test.family, writingSystem))
continue;
// as we know the script is supported, we can be sure
@ -2869,10 +2876,9 @@ QString QFontDatabase::resolveFontFamilyAlias(const QString &family)
Q_GUI_EXPORT QStringList qt_sort_families_by_writing_system(QChar::Script script, const QStringList &families)
{
const size_t writingSystem =
std::find(scriptForWritingSystem,
scriptForWritingSystem + QFontDatabase::WritingSystemsCount, script)
- scriptForWritingSystem;
size_t writingSystem = std::find(scriptForWritingSystem,
scriptForWritingSystem + QFontDatabase::WritingSystemsCount,
script) - scriptForWritingSystem;
if (writingSystem == QFontDatabase::Any
|| writingSystem >= QFontDatabase::WritingSystemsCount) {
return families;
@ -2892,30 +2898,9 @@ Q_GUI_EXPORT QStringList qt_sort_families_by_writing_system(QChar::Script script
}
}
bool isSupported = false;
if (testFamily != nullptr) {
isSupported = testFamily->writingSystems[writingSystem] & QtFontFamily::Supported;
auto otherWritingSystem = writingSystem;
// test other writing systems
while (!isSupported) {
otherWritingSystem =
std::find(&scriptForWritingSystem[otherWritingSystem + 1],
scriptForWritingSystem + QFontDatabase::WritingSystemsCount,
script)
- scriptForWritingSystem;
if (otherWritingSystem >= QFontDatabase::WritingSystemsCount)
break;
isSupported |=
testFamily->writingSystems[otherWritingSystem] & QtFontFamily::Supported;
}
}
uint order = i;
if (!isSupported) {
if (testFamily == nullptr
|| !familySupportsWritingSystem(testFamily, writingSystem)) {
order |= 1u << 31;
}