path: root/src/gui/painting/qpaintdevice.cpp
diff options
authorMorten Johan Sørvig <>2015-06-19 16:40:39 +0200
committerSimon Hausmann <>2015-07-30 04:04:01 +0000
commitdcd2debe625841ee8cba6d13a56cde7613c40358 (patch)
treed1d1e6c98d9cc5d81f29a389721acca6a9f7d150 /src/gui/painting/qpaintdevice.cpp
parent0167ace5f0a7e5ad80ce95efc99c86235bcf8c0d (diff)
Enable non-integer device pixel ratio
Work around QPaintDevice::metric's int return type by adding a new metric that returns a scaled devicePixelRatio. Choose a scale factor that gives us more than enough range. The QPaintDevice::devicePixelRatio() convenience accessor is public API and can unfortunately not be changed to return a qreal. Add devicePixelRatioF() which returns the (unscaled) devicePixelRatio. Change all call sites of QPaintDevice::devicePixelRatio() to use QPainDevice::devicePixelRatioF(). Task-number: QTBUG-46615 Change-Id: I97ec4000fe379b7ff5e1624a871ae2512790aad9 Reviewed-by: Paul Olav Tvete <> Reviewed-by: Lars Knoll <>
Diffstat (limited to 'src/gui/painting/qpaintdevice.cpp')
1 files changed, 6 insertions, 0 deletions
diff --git a/src/gui/painting/qpaintdevice.cpp b/src/gui/painting/qpaintdevice.cpp
index bbf8e8f170..2332d11a03 100644
--- a/src/gui/painting/qpaintdevice.cpp
+++ b/src/gui/painting/qpaintdevice.cpp
@@ -79,7 +79,13 @@ Q_GUI_EXPORT int qt_paint_device_metric(const QPaintDevice *device, QPaintDevice
int QPaintDevice::metric(PaintDeviceMetric m) const
+ // Fallback: A subclass has not implemented PdmDevicePixelRatioScaled but might
+ // have implemented PdmDevicePixelRatio.
+ if (m == PdmDevicePixelRatioScaled)
+ return this->metric(PdmDevicePixelRatio) * devicePixelRatioFScale();
qWarning("QPaintDevice::metrics: Device has no metric information");
if (m == PdmDpiX) {
return 72;
} else if (m == PdmDpiY) {