Make QOpenGLWidget work with QT_WIDGETS_HIGHDPI_DOWNSCALE

Get the DPR from QWidget::metric(), which has a code path
for handling the QT_WIDGETS_HIGHDPI_DOWNSCALE case.

Fixes: QTBUG-111105
Change-Id: I821cbdf00423de211719173ae5c0af7b76594f60
Reviewed-by: Eirik Aavitsland <[email protected]>
(cherry picked from commit 433d67e767478ce946cd04d8ad4ff73051c14773)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>

1 files changed, 2 insertions, 8 deletions

diff --git a/src/openglwidgets/qopenglwidget.cpp b/src/openglwidgets/qopenglwidget.cpp
index a21bd3d5519..cbc0b751e85 100644
--- a/src/openglwidgets/qopenglwidget.cpp
+++ b/src/openglwidgets/qopenglwidget.cpp
@@ -1609,15 +1609,9 @@ int QOpenGLWidget::metric(QPaintDevice::PaintDeviceMetric metric) const
         else
             return qRound(dpmy * 0.0254);
     case PdmDevicePixelRatio:
-        if (window)
-            return int(window->devicePixelRatio());
-        else
-            return 1.0;
+        return QWidget::metric(metric);
     case PdmDevicePixelRatioScaled:
-        if (window)
-            return int(window->devicePixelRatio() * devicePixelRatioFScale());
-        else
-            return int(devicePixelRatioFScale());
+        return QWidget::metric(metric);
     default:
         qWarning("QOpenGLWidget::metric(): unknown metric %d", metric);
         return 0;