Merge pull request #12102 from Kolcha/hidpi

Delegate GUI scaling work to Qt

src/app/main.cpp

@@ -133,6 +133,12 @@ int main(int argc, char *argv[])
     // We must save it here because QApplication constructor may change it
     bool isOneArg = (argc == 2);
 
+#if !defined(DISABLE_GUI) && (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
+    // Attribute Qt::AA_EnableHighDpiScaling must be set before QCoreApplication is created
+    if (qgetenv("QT_ENABLE_HIGHDPI_SCALING").isEmpty() && qgetenv("QT_AUTO_SCREEN_SCALE_FACTOR").isEmpty())
+        Application::setAttribute(Qt::AA_EnableHighDpiScaling, true);
+#endif
+
     try {
         // Create Application
         const QString appId = QLatin1String("qBittorrent-") + Utils::Misc::getUserIDString();

src/gui/utils.cpp

@@ -62,6 +62,10 @@ void Utils::Gui::resize(QWidget *widget, const QSize &newSize)
 
 qreal Utils::Gui::screenScalingFactor(const QWidget *widget)
 {
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
+    Q_UNUSED(widget);
+    return 1;
+#else
     if (!widget)
         return 1;
 
@@ -77,6 +81,7 @@ qreal Utils::Gui::screenScalingFactor(const QWidget *widget)
 #else
     return widget->devicePixelRatioF();
 #endif // Q_OS_WIN
+#endif // QT_VERSION
 }
 
 QPixmap Utils::Gui::scaledPixmap(const QIcon &icon, const QWidget *widget, const int height)