QDpi: divide the forced DPI by the scaling factor, as Qt 5.13 did

When setting a DPI in xrdb, it should have the same effect on apps that enable scaling and apps that don't (including Qt4 and GTK applications). That's what happened in Qt 5.13, while the recent changes removed that division, and as a result the fonts were huge in Qt5 apps compared to Qt4/GTK/kwin/plasmashell/krunner (which don't scale, but do honor the font DPI). Change-Id: Icd7be2d15a9b50982ae624e41bd9e546f315d58b Reviewed-by: Friedemann Kleint <[email protected]> Reviewed-by: Morten Johan Sørvig <[email protected]>
chain78 · Sep 13, 2019 · 00d0a53 · 00d0a53
1 parent c6bde29
commit 00d0a53
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
@@ -680,8 +680,11 @@ QDpi QHighDpiScaling::logicalDpi(const QScreen *screen)
     if (!screen || !screen->handle())
         return QDpi(96, 96);
 
-    if (!m_usePixelDensity)
-        return QPlatformScreen::overrideDpi(screen->handle()->logicalDpi());
+    if (!m_usePixelDensity) {
+        const qreal screenScaleFactor = screenSubfactor(screen->handle());
+        const QDpi dpi = QPlatformScreen::overrideDpi(screen->handle()->logicalDpi());
+        return QDpi{ dpi.first / screenScaleFactor, dpi.second / screenScaleFactor };
+    }
 
     const qreal scaleFactor = rawScaleFactor(screen->handle());
     const qreal roundedScaleFactor = roundScaleFactor(scaleFactor);