HiDPI Display of Checkboxes

James.Emerton · wrote on 15 Jan 2018, 20:51

I am currently in the process of porting a PyQt application to Qt and enabling HiDPI support. I've set Qt.AA_EnableHighDpiScaling and almost everything displays correctly, except for checkboxes.

I came across https://bugreports.qt.io/browse/QTBUG-44478 which appears to indicate that this problem exists in the base QWindowsStyle but I am also seeing the same behavior on Windows 10 using the QWindowsVistaStyle.

Is anyone else experiencing this issue?

SGaist · wrote on 15 Jan 2018, 21:13

Hi,

You might want to check this submission and build a custom version of the plugin with this applied.

James.Emerton · wrote on 18 Jan 2018, 22:58

I did some exploratory debugging and found that (on Windows 10) QWindowsStyle::drawPrimitive() is not being called to render checkboxes, but rather they are being drawn with DrawThemeBackgroundEx() from uxstyle.dll (which I would have expected to support High DPI correctly.)

After looking at the screen shots attached to the ticket referenced above I discovered that I have a different sort of drawing problem; checkboxes are being render correctly, but at the same size (13px) regardless of device scaling.

On Windows 7 checkboxes appear to render correctly with device scaling enabled.