3 files changed, 14 insertions, 0 deletions
diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h
index fc5207fa25..9381f01639 100644
--- a/src/corelib/global/qnamespace.h
+++ b/src/corelib/global/qnamespace.h
@@ -496,6 +496,7 @@ public:
         AA_UseSoftwareOpenGL = 17,
         AA_ShareOpenGLContexts = 18,
         AA_SetPalette = 19,
+        AA_NoHighDpiScaling = 20,
 
         // Add new attributes before this line
         AA_AttributeCount
diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc
index 970e1b1f42..4aed887b19 100644
--- a/src/corelib/global/qnamespace.qdoc
+++ b/src/corelib/global/qnamespace.qdoc
@@ -197,6 +197,11 @@
     \value AA_SetPalette Indicates whether a palette was explicitly set on the
            QApplication/QGuiApplication. This value has been added in Qt 5.5.
 
+    \value AA_NoHighDpiScaling Disables all high-DPI scaling in Qt, exposing window
+           system coordinates. Note that the window system may do its own scaling,
+           so this does not guarantee that QPaintDevice::devicePixelRatio() will
+           be equal to 1. This value has been added in Qt 5.6.
+
     The following values are obsolete:
 
     \value AA_ImmediateWidgetCreation This attribute is no longer fully
diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
index e574a79370..46c9f671df 100644
--- a/src/gui/kernel/qhighdpiscaling.cpp
+++ b/src/gui/kernel/qhighdpiscaling.cpp
@@ -142,6 +142,11 @@ QDpi QHighDpiScaling::m_logicalDpi; // The scaled logical DPI of the primary scr
 */
 void QHighDpiScaling::initHighDpiScaling()
 {
+    if (QCoreApplication::testAttribute(Qt::AA_NoHighDpiScaling)) {
+        m_factor = 1;
+        m_active = false;
+        return;
+    }
     m_factor = initialScaleFactor();
     bool usePlatformPluginPixelDensity = qEnvironmentVariableIsSet(autoScreenEnvVar)
                                          || qgetenv(legacyDevicePixelEnvVar).toLower() == "auto";
@@ -157,6 +162,9 @@ void QHighDpiScaling::initHighDpiScaling()
 
 void QHighDpiScaling::updateHighDpiScaling()
 {
+    if (QCoreApplication::testAttribute(Qt::AA_NoHighDpiScaling))
+        return;
+
     if (m_usePixelDensity && !m_pixelDensityScalingActive) {
         Q_FOREACH (QScreen *screen, QGuiApplication::screens()) {
             if (!qFuzzyCompare(screenSubfactor(screen->handle()), qreal(1))) {