Make it possible to enable non-scalable font scaling

Windows native font engine supports scaling of non-scalalble fonts, so
make it possible to do so.
Added two functions to QPlatformFontDatabase: fontsAlwaysScalable() and
standardSizes(), and made fontsAlwaysScalable() to return true for
Windows native font database.

Windows Freetype font engine doesn't seem to support scaling of
non-scalable fonts, so didn't enable it in there.

Added implementation of standardSizes() for Mac OS.

Task-number: QTBUG-24970
Change-Id: I41c9356ede8a37b7c61db94340dbeb5b629f34b9
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
Reviewed-by: Jiang Jiang <jiang.jiang@nokia.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/gui/text/qfontdatabase_qpa.cpp b/src/gui/text/qfontdatabase_qpa.cpp
index 0014efc450..c2a3aa9722 100644
--- a/src/gui/text/qfontdatabase_qpa.cpp
+++ b/src/gui/text/qfontdatabase_qpa.cpp
@@ -161,9 +161,12 @@ QFontEngine *loadSingleEngine(int script,
     Q_UNUSED(foundry);
 
     Q_ASSERT(size);
+    QPlatformFontDatabase *pfdb = QGuiApplicationPrivate::platformIntegration()->fontDatabase();
     int pixelSize = size->pixelSize;
-    if (!pixelSize || (style->smoothScalable && pixelSize == SMOOTH_SCALABLE))
+    if (!pixelSize || (style->smoothScalable && pixelSize == SMOOTH_SCALABLE)
+        || pfdb->fontsAlwaysScalable()) {
         pixelSize = request.pixelSize;
+    }
 
     QFontDef def = request;
     def.pixelSize = pixelSize;
@@ -171,7 +174,6 @@ QFontEngine *loadSingleEngine(int script,
     QFontCache::Key key(def,script);
     QFontEngine *engine = QFontCache::instance()->findEngine(key);
     if (!engine) {
-        QPlatformFontDatabase *pfdb = QGuiApplicationPrivate::platformIntegration()->fontDatabase();
         engine = pfdb->fontEngine(def,QUnicodeTables::Script(script),size->handle);
         if (engine) {
             QFontCache::Key key(def,script);