Parse QT_SCREEN_SCALE_FACTORS spec only once

Move parsing to initHighDpiScaling() and store the parsed
factors in a vector. The factors are later applied in
updateHighDpiScaling() where the factor list is compared
to the screen list.

Change-Id: I59fc67b84932dbe69868a3683686a91e51333104
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/gui/kernel/qhighdpiscaling_p.h b/src/gui/kernel/qhighdpiscaling_p.h
index 3e7ba2f5e1..8460b3ec2e 100644
--- a/src/gui/kernel/qhighdpiscaling_p.h
+++ b/src/gui/kernel/qhighdpiscaling_p.h
@@ -126,11 +126,19 @@ public:
     static QDpi logicalDpi(const QScreen *screen);
 
 private:
+    struct ScreenFactor {
+        ScreenFactor(QString name, qreal factor)
+            :name(name), factor(factor) { }
+        QString name;
+        qreal factor;
+    };
+
     static qreal rawScaleFactor(const QPlatformScreen *screen);
     static qreal roundScaleFactor(qreal rawFactor);
     static QDpi effectiveLogicalDpi(const QPlatformScreen *screen, qreal rawFactor, qreal roundedFactor);
     static qreal screenSubfactor(const QPlatformScreen *screen);
     static QScreen *screenForPosition(Point position, QScreen *guess);
+    static QVector<QHighDpiScaling::ScreenFactor> parseScreenScaleFactorsSpec(const QStringView &screenScaleFactors);
 
     static qreal m_factor;
     static bool m_active;
@@ -139,7 +147,7 @@ private:
     static bool m_globalScalingActive;
     static bool m_screenFactorSet;
     static bool m_usePhysicalDpi;
-    static QString m_screenFactorsSpec;
+    static QVector<ScreenFactor> m_screenFactors;
     static DpiAdjustmentPolicy m_dpiAdjustmentPolicy;
     static QHash<QString, qreal> m_namedScreenScaleFactors;
 };