WIP: Add PdmDevicePixelRatioScaled.

Work around QPainDevice::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 QPainDevice::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 QPainDevice::devicePixelRatio()
to use QPainDevice::devicePixelRatioF().

Task-number: QTBUG-38858
Change-Id: Ia97c24e1c7b10241d6425fab2fa513702bb750b8

1 files changed, 2 insertions, 2 deletions

diff --git a/src/widgets/styles/qmacstyle_mac.mm b/src/widgets/styles/qmacstyle_mac.mm
index 67970ba33d..95a41b4830 100644
--- a/src/widgets/styles/qmacstyle_mac.mm
+++ b/src/widgets/styles/qmacstyle_mac.mm
@@ -1989,7 +1989,7 @@ void QMacStylePrivate::drawColorlessButton(const HIRect &macRect, HIThemeButtonD
         }
     }
 
-    int devicePixelRatio = p->device()->devicePixelRatio();
+    int devicePixelRatio = p->device()->devicePixelRatioF();
     int width = devicePixelRatio * (int(macRect.size.width) + extraWidth);
     int height = devicePixelRatio * (int(macRect.size.height) + extraHeight);
 
@@ -7216,7 +7216,7 @@ CGContextRef qt_mac_cg_context(const QPaintDevice *pdev)
         }
 
         CGContextTranslateCTM(ret, 0, pm->height());
-        int devicePixelRatio = pdev->devicePixelRatio();
+        qreal devicePixelRatio = pdev->devicePixelRatioF();
         CGContextScaleCTM(ret, devicePixelRatio, devicePixelRatio);
         CGContextScaleCTM(ret, 1, -1);
         return ret;