Allow selecting fonts with irregular style names

Fonts like "Helvetica Neue UltraLight" or "Skia Regular Black
Condensed" can't be selected in Qt because either they don't
report correct numeric values for weight/stretch/etc. or these
values are not mapped from QFont enums in a linear way. Thus
we provide a shortcut to select these fonts with PostScript
name or full name without resorting to family name matching in
QFontDatabase (these fonts are not registered in font database
anyway). After this, we can simply use:

    QFont font("Helvetica Neue");
    font.setStyleName("UltraLight");

to select these fonts. QCoreTextFontEngineMulti matched like
this can be created directly from the CTFontRef instance
instead of creating from the font name, making this process
faster.

The commit also cleaned up the font loading process in Mac
font database a bit, moving the code for family matching into
a separate function.

Add QFontInfo::styleName() and QRawFont::styleName() to access
the resolved style name for a font.

Task-number: QTBUG-19366
Change-Id: Iad07768c02ed06cc8d6b7395dec554384f410506
Reviewed-on: http://codereview.qt.nokia.com/333
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Jiang Jiang <jiang.jiang@nokia.com>
(cherry picked from commit 97391be5ebddc62545ddb88f92fc2045bfa10711)

1 files changed, 84 insertions, 58 deletions

diff --git a/src/gui/text/qfontdatabase_mac.cpp b/src/gui/text/qfontdatabase_mac.cpp
index 6fdaf06..724dbf6 100644
--- a/src/gui/text/qfontdatabase_mac.cpp
+++ b/src/gui/text/qfontdatabase_mac.cpp
@@ -249,6 +249,63 @@ static inline float weightToFloat(unsigned int weight)
     return (weight - 50) / 100.0;
 }
 
+static QFontEngine *loadFromDatabase(const QFontDef &req, const QFontPrivate *d)
+{
+#if defined(QT_MAC_USE_COCOA)
+    QCFString fontName = NULL;
+#else
+    ATSFontFamilyRef familyRef = 0;
+    ATSFontRef fontRef = 0;
+#endif
+
+    QStringList family_list = familyList(req);
+
+    const char *stylehint = styleHint(req);
+    if (stylehint)
+        family_list << QLatin1String(stylehint);
+
+    // add QFont::defaultFamily() to the list, for compatibility with previous versions
+    family_list << QApplication::font().defaultFamily();
+
+    QMutexLocker locker(fontDatabaseMutex());
+    QFontDatabasePrivate *db = privateDb();
+    if (!db->count)
+        initializeDb();
+    for (int i = 0; i < family_list.size(); ++i) {
+        for (int k = 0; k < db->count; ++k) {
+            if (db->families[k]->name.compare(family_list.at(i), Qt::CaseInsensitive) == 0) {
+                QByteArray family_name = db->families[k]->name.toUtf8();
+#if defined(QT_MAC_USE_COCOA)
+                QCFType<CTFontRef> ctFont = CTFontCreateWithName(QCFString(db->families[k]->name), 12, NULL);
+                if (ctFont) {
+                    fontName = CTFontCopyFullName(ctFont);
+                    goto found;
+                }
+#else
+                familyRef = ATSFontFamilyFindFromName(QCFString(db->families[k]->name), kATSOptionFlagsDefault);
+                if (familyRef) {
+                    fontRef = ATSFontFindFromName(QCFString(db->families[k]->name), kATSOptionFlagsDefault);
+                    goto found;
+                }
+#endif
+            }
+        }
+    }
+found:
+#ifdef QT_MAC_USE_COCOA
+    if (fontName)
+        return new QCoreTextFontEngineMulti(fontName, req, d->kerning);
+#else
+    if (familyRef) {
+        QCFString actualName;
+        if (ATSFontFamilyGetName(familyRef, kATSOptionFlagsDefault, &actualName) == noErr)
+            req.family = actualName;
+        return new QFontEngineMacMulti(familyRef, req, fontDef, d->kerning);
+    }
+#endif
+    return NULL;
+}
+
 void QFontDatabase::load(const QFontPrivate *d, int script)
 {
     // sanity checks
@@ -289,69 +346,38 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
         return; // the font info and fontdef should already be filled
     }
 
-    //find the font
-    QStringList family_list = familyList(req);
-
-    const char *stylehint = styleHint(req);
-    if (stylehint)
-        family_list << QLatin1String(stylehint);
-
-    // add QFont::defaultFamily() to the list, for compatibility with
-    // previous versions
-    family_list << QApplication::font().defaultFamily();
-
+    QFontEngine *engine = NULL;
 #if defined(QT_MAC_USE_COCOA)
-    QCFString fontName = NULL, familyName = NULL;
-#else
-    ATSFontFamilyRef familyRef = 0;
-    ATSFontRef fontRef = 0;
-#endif
-
-    QMutexLocker locker(fontDatabaseMutex());
-    QFontDatabasePrivate *db = privateDb();
-    if (!db->count)
-        initializeDb();
-    for(int i = 0; i < family_list.size(); ++i) {
-        for (int k = 0; k < db->count; ++k) {
-            if (db->families[k]->name.compare(family_list.at(i), Qt::CaseInsensitive) == 0) {
-                QByteArray family_name = db->families[k]->name.toUtf8();
-#if defined(QT_MAC_USE_COCOA)
-                QCFType<CTFontRef> ctFont = CTFontCreateWithName(QCFString(db->families[k]->name), 12, NULL);
-                if (ctFont) {
-                    fontName = CTFontCopyFullName(ctFont);
-                    familyName = CTFontCopyFamilyName(ctFont);
-                    goto FamilyFound;
-                }
-#else
-                familyRef = ATSFontFamilyFindFromName(QCFString(db->families[k]->name), kATSOptionFlagsDefault);
-                if (familyRef) {
-                    fontRef = ATSFontFindFromName(QCFString(db->families[k]->name), kATSOptionFlagsDefault);
-                    goto FamilyFound;
-                }
-#endif
+    // Shortcut to get the font directly without going through the font database
+    if (!req.family.isEmpty() && !req.styleName.isEmpty()) {
+        QCFString expectedFamily = QCFString(req.family);
+        QCFString expectedStyle = QCFString(req.styleName);
+
+        QCFType<CFMutableDictionaryRef> attributes = CFDictionaryCreateMutable(NULL, 0,
+            &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
+        CFDictionaryAddValue(attributes, kCTFontFamilyNameAttribute, expectedFamily);
+        CFDictionaryAddValue(attributes, kCTFontStyleNameAttribute, expectedStyle);
+
+        QCFType<CTFontDescriptorRef> descriptor = CTFontDescriptorCreateWithAttributes(attributes);
+        CGAffineTransform transform = qt_transform_from_fontdef(req);
+        QCFType<CTFontRef> ctFont = CTFontCreateWithFontDescriptor(descriptor, req.pixelSize, &transform);
+        if (ctFont) {
+            QCFString familyName = CTFontCopyFamilyName(ctFont);
+            // Only accept the font if the family name is exactly the same as we specified
+            if (CFEqual(expectedFamily, familyName)) {
+                engine = new QCoreTextFontEngineMulti(ctFont, req, d->kerning);
             }
         }
     }
-FamilyFound:
-    //fill in the engine's font definition
-    QFontDef fontDef = d->request; //copy..
-    if(fontDef.pointSize < 0)
-        fontDef.pointSize = qt_mac_pointsize(fontDef, d->dpi);
-    else
-        fontDef.pixelSize = qt_mac_pixelsize(fontDef, d->dpi);
-
-#ifdef QT_MAC_USE_COCOA
-    fontDef.family = familyName;
-    QFontEngine *engine = new QCoreTextFontEngineMulti(fontName, fontDef, d->kerning);
-#else
-    QCFString actualName;
-    if (ATSFontFamilyGetName(familyRef, kATSOptionFlagsDefault, &actualName) == noErr)
-        fontDef.family = actualName;
-    QFontEngine *engine = new QFontEngineMacMulti(familyRef, fontRef, fontDef, d->kerning);
 #endif
-    d->engineData->engine = engine;
-    engine->ref.ref(); //a ref for the engineData->engine
-    QFontCache::instance()->insertEngine(key, engine);
+    if (!engine)
+        engine = loadFromDatabase(req, d);
+
+    if (engine) {
+        d->engineData->engine = engine;
+        engine->ref.ref();
+        QFontCache::instance()->insertEngine(key, engine);
+    }
 }
 
 static void registerFont(QFontDatabasePrivate::ApplicationFont *fnt)