Font Database: Add support for private, system UI font families

We introduce QPlatformFontDatabase::isPrivateFontFamily() to allow
testing for private, system UI font families. Both QFontComboBox
and QFontDialog need to filter out those private font families
which, by definition, should be hidden from the end user.

(The textedit example had to be updated to fix the issue where the
default font would be private. In 5.4, we will be adding an equivalent,
public API in QFontDatabase, and a better solution for the textedit
example and QTexEdit in general).

In particular, on OS X and iOS, private fonts are used for the system
UI font. Those have their font family name prefixed by a dot.
QCoreTextFontDatabase knows about this, and makes sure those are
tested positive as private font families. In order to have a cleaner
layer separation, we moved the QPA theme font resolution from the
platform theme classes into QCoreTextFontDatabase for both Cocoa and
iOS QPA plugins.

In both cases, we use CoreText's CTFontCreateUIFontForLanguage(), that
nicely maps to the HITheme API we were using so far on Mac. That means
one HITheme dependency less. We also cache the font descriptors we get
for these font for each time QCTFD::populateFamilies() gets called.
(While not common, this currently happens in auto-tests, like
tst_QFontDatabase, and could happen in actual applications -- specially
when adding and removing application fonts.)

Change-Id: Ic6f0b60f9f597afee1a43596a669742dc546b97f
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

4 files changed, 13 insertions, 58 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoasystemsettings.h b/src/plugins/platforms/cocoa/qcocoasystemsettings.h
index 9ce301f7e7..3861da6230 100644
--- a/src/plugins/platforms/cocoa/qcocoasystemsettings.h
+++ b/src/plugins/platforms/cocoa/qcocoasystemsettings.h
@@ -50,7 +50,6 @@ QT_BEGIN_NAMESPACE
 
 QPalette * qt_mac_createSystemPalette();
 QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes();
-QHash<QPlatformTheme::Font, QFont *>  qt_mac_createRoleFonts();
 
 QT_END_NAMESPACE
 
diff --git a/src/plugins/platforms/cocoa/qcocoasystemsettings.mm b/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
index f18be8b69c..67fa66ad63 100644
--- a/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
+++ b/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
@@ -230,48 +230,4 @@ QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
     return palettes;
 }
 
-QFont *qt_mac_qfontForThemeFont(ThemeFontID themeID)
-{
-    CTFontUIFontType ctID = HIThemeGetUIFontType(themeID);
-    QCFType<CTFontRef> ctfont = CTFontCreateUIFontForLanguage(ctID, 0, 0);
-    QString familyName = QCFString(CTFontCopyFamilyName(ctfont));
-    QCFType<CFDictionaryRef> dict = CTFontCopyTraits(ctfont);
-    CFNumberRef num = static_cast<CFNumberRef>(CFDictionaryGetValue(dict, kCTFontWeightTrait));
-    float fW;
-    CFNumberGetValue(num, kCFNumberFloat32Type, &fW);
-    QFont::Weight wght = fW > 0. ? QFont::Bold : QFont::Normal;
-    num = static_cast<CFNumberRef>(CFDictionaryGetValue(dict, kCTFontSlantTrait));
-    CFNumberGetValue(num, kCFNumberFloatType, &fW);
-    bool italic = (fW != 0.0);
-    return new QFont(familyName, CTFontGetSize(ctfont), wght, italic);
-}
-
-QHash<QPlatformTheme::Font, QFont *> qt_mac_createRoleFonts()
-{
-    QHash<QPlatformTheme::Font, QFont *> fonts;
-
-    fonts.insert(QPlatformTheme::SystemFont, qt_mac_qfontForThemeFont(kThemeApplicationFont));
-    fonts.insert(QPlatformTheme::PushButtonFont, qt_mac_qfontForThemeFont(kThemePushButtonFont));
-    fonts.insert(QPlatformTheme::ListViewFont, qt_mac_qfontForThemeFont(kThemeViewsFont));
-    fonts.insert(QPlatformTheme::ListBoxFont, qt_mac_qfontForThemeFont(kThemeViewsFont));
-    fonts.insert(QPlatformTheme::TitleBarFont, qt_mac_qfontForThemeFont(kThemeWindowTitleFont));
-    fonts.insert(QPlatformTheme::MenuFont, qt_mac_qfontForThemeFont(kThemeMenuItemFont));
-    fonts.insert(QPlatformTheme::MenuBarFont, qt_mac_qfontForThemeFont(kThemeMenuItemFont));
-    fonts.insert(QPlatformTheme::ComboMenuItemFont, qt_mac_qfontForThemeFont(kThemeSystemFont));
-    fonts.insert(QPlatformTheme::HeaderViewFont, qt_mac_qfontForThemeFont(kThemeSmallSystemFont));
-    fonts.insert(QPlatformTheme::TipLabelFont, qt_mac_qfontForThemeFont(kThemeSmallSystemFont));
-    fonts.insert(QPlatformTheme::LabelFont, qt_mac_qfontForThemeFont(kThemeSystemFont));
-    fonts.insert(QPlatformTheme::ToolButtonFont, qt_mac_qfontForThemeFont(kThemeSmallSystemFont));
-    fonts.insert(QPlatformTheme::MenuItemFont, qt_mac_qfontForThemeFont(kThemeMenuItemFont));
-    fonts.insert(QPlatformTheme::ComboLineEditFont, qt_mac_qfontForThemeFont(kThemeViewsFont));
-    fonts.insert(QPlatformTheme::SmallFont, qt_mac_qfontForThemeFont(kThemeSmallSystemFont));
-    fonts.insert(QPlatformTheme::MiniFont, qt_mac_qfontForThemeFont(kThemeMiniSystemFont));
-
-    QFont* fixedFont = new QFont(QStringLiteral("Monaco"), fonts[QPlatformTheme::SystemFont]->pointSize());
-    fixedFont->setStyleHint(QFont::TypeWriter);
-    fonts.insert(QPlatformTheme::FixedFont, fixedFont);
-
-    return fonts;
-}
-
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.mm b/src/plugins/platforms/cocoa/qcocoatheme.mm
index dce1671800..ae42fee82c 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.mm
+++ b/src/plugins/platforms/cocoa/qcocoatheme.mm
@@ -60,6 +60,7 @@
 #include <QtCore/qfileinfo.h>
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtGui/qpainter.h>
+#include <QtPlatformSupport/private/qcoretextfontdatabase_p.h>
 #include <qpa/qplatformintegration.h>
 #include <qpa/qplatformnativeinterface.h>
 
@@ -134,6 +135,12 @@ const QPalette *QCocoaTheme::palette(Palette type) const
     return 0;
 }
 
+QHash<QPlatformTheme::Font, QFont *> qt_mac_createRoleFonts()
+{
+    QCoreTextFontDatabase *ctfd = static_cast<QCoreTextFontDatabase *>(QGuiApplicationPrivate::platformIntegration()->fontDatabase());
+    return ctfd->themeFonts();
+}
+
 const QFont *QCocoaTheme::font(Font type) const
 {
     if (m_fonts.isEmpty()) {
diff --git a/src/plugins/platforms/ios/qiostheme.mm b/src/plugins/platforms/ios/qiostheme.mm
index e7093185aa..e51e97bd5a 100644
--- a/src/plugins/platforms/ios/qiostheme.mm
+++ b/src/plugins/platforms/ios/qiostheme.mm
@@ -46,6 +46,10 @@
 
 #include <QtGui/QFont>
 
+#include <QtPlatformSupport/private/qcoretextfontdatabase_p.h>
+#include <QtGui/private/qguiapplication_p.h>
+#include <qpa/qplatformintegration.h>
+
 #include <UIKit/UIFont.h>
 #include <UIKit/UIInterface.h>
 
@@ -75,19 +79,8 @@ QVariant QIOSTheme::themeHint(ThemeHint hint) const
 const QFont *QIOSTheme::font(Font type) const
 {
     if (m_fonts.isEmpty()) {
-        // The real system font on iOS is '.Helvetica Neue UI', as returned by both [UIFont systemFontOfSize]
-        // and CTFontCreateUIFontForLanguage(kCTFontSystemFontType, ...), but this font is not included when
-        // populating the available fonts in QCoreTextFontDatabase::populateFontDatabase(), since the font
-        // is internal to iOS and not supposed to be used by applications. We could potentially add this
-        // font to the font-database, but it would then show up when enumerating user fonts from Qt
-        // applications since we don't have a flag in Qt to mark a font as a private system font.
-        // For now we hard-code the font to Helvetica, which should be very close to the actual
-        // system font.
-        QLatin1String systemFontFamilyName("Helvetica");
-        m_fonts.insert(QPlatformTheme::SystemFont, new QFont(systemFontFamilyName, [UIFont systemFontSize]));
-        m_fonts.insert(QPlatformTheme::SmallFont, new QFont(systemFontFamilyName, [UIFont smallSystemFontSize]));
-        m_fonts.insert(QPlatformTheme::LabelFont, new QFont(systemFontFamilyName, [UIFont labelFontSize]));
-        m_fonts.insert(QPlatformTheme::PushButtonFont, new QFont(systemFontFamilyName, [UIFont buttonFontSize]));
+        QCoreTextFontDatabase *ctfd = static_cast<QCoreTextFontDatabase *>(QGuiApplicationPrivate::platformIntegration()->fontDatabase());
+        m_fonts = ctfd->themeFonts();
     }
 
     return m_fonts.value(type, 0);