Only turn off font hinting when really scaling

We don't want to turn off font hinting based on whether auto-scaling is on,
otherwise Qt Creator will look bad on a low-DPI screen. Instead, we turn it
off only if we have at least one screen that is scaled.

QHighDpiScaling::isActive() now means that there is actual scaling going on.
There is currently no need for the old meaning, so this change does not include
QHighDpiScaling::isEnabled().

Note that nothing can save us from the case where there is one high-DPI and
one low-DPI screen.  In that case we choose looking bad on the low-DPI screen
instead of looking like crap on the high-DPI screen. Also note that our font
system we doesn't allow us to change our minds on hinting later when screens
are plugged in or removed.

Change-Id: I14a4ec7a49f4ba74a4c74684c7b951d0a71b951d
Reviewed-by: Morten Johan Sørvig <morten.sorvig@theqtcompany.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp b/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp
index 112bb8e0a6..c40bbf41b1 100644
--- a/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp
+++ b/src/platformsupport/fontdatabases/fontconfig/qfontconfigdatabase.cpp
@@ -33,6 +33,7 @@
 
 #include "qfontconfigdatabase_p.h"
 #include "qfontenginemultifontconfig_p.h"
+#include "qhighdpiscaling_p.h"
 
 #include <QtCore/QList>
 #include <QtCore/QElapsedTimer>
@@ -553,10 +554,8 @@ QFontEngine::HintStyle defaultHintStyleFromMatch(QFont::HintingPreference hintin
         break;
     }
 
-    if (QGuiApplication::platformNativeInterface()->nativeResourceForScreen("nofonthinting",
-                         QGuiApplication::primaryScreen())) {
+    if (QHighDpiScaling::isActive())
         return QFontEngine::HintNone;
-    }
 
     int hint_style = 0;
     if (FcPatternGetInteger (match, FC_HINT_STYLE, 0, &hint_style) == FcResultMatch) {