Display issues with DUI on Mac for CCP4 8.0

[dagewa]

As reported by the CCP4 core team, DUI in the CCP4 8.0 test bundle on MacOS 11.6.1 Big Sur (http://devtools.fg.oisin.rc-harwell.ac.uk/downloads/packages/ccp4-20211117-osx-clang-py3-pyside2.tar.gz) has some issues with image display. The diffraction images are not displayed properly: only a greyish/purplish circle is visible, not the diffraction spots. The “Palette tuning” controls only changes diameter of the circle, but does not make the spots visible. Also, the “Palette tuning” controls are transparent, such that the windows underneath the DUI window are visible.

I don't know if this is specific to the CCP4 build, or related to that version of MacOS.

[dagewa]

Update: apparently a standalone DUI installed into DIALS 3.7.1 does not have a broken image viewer, but does have a transparent palette gradient. So there are two issues: a broken image viewer, which is limited to the CCP4 8.0 bundle, and a transparent palette, which appears on MacOS 11.6.1.

[dagewa]

Briefly looked at this with Luiso. We suspect the palette image is being displayed, but that black colour is being interpreted as transparent. Function to look at is build_qimg. Neither of us have a suitable Mac to debug this though.