The release of Mac OS X 10.6 (Snow Leopard) snuck up on me while I have been working hard on a major new release of PerfectTablePlan plan. I didn’t really want to risk messing up my stable Mac development machine by installing it, so I asked testlab2.com (who have been doing some third party testing for me) to test my latest beta on it.
Bad news. All the combo boxes in my application (which work fine in Mac OS X 10.3, 10.4 and 10.5) have visual artefacts on Mac OS X 10.6. They work fine, but they don’t look right. I wondered if the artefact could be unique to some weird configuration on testlab2’s test machine, so I asked the fine folk on macsb mailing list to see if they could replicate it. 4 of them tried (thanks Cesar, Jon, Aaron and Pierre) and they all saw the visual artefacts. Damn.
I posted a question on the qt-interest forum. The single response (thanks Francesco) mentioned that this issue had been reported in the Qt development blog. I managed to find the blog post, applied the recommended single line code patch to Qt 4.4.2 and rebuilt everything. Cesar from macsb kindly re-tried the new binaries and reports that this improved things, but some artefacts are still visible the first time a combo box is shown. Perhaps the patch works better for Qt 4.5.

Note the artefacts at the top and bottom of the combo box drop-down list
It looks like I am going to have to release it like this, unless someone knows of a better patch. This is very annoying after the months of hard work I have put into the new release. Aesthetics are important for commercial software, especially on the Mac. This could cost me quite a few sales.
I am not on the very latest release of Qt, but apparently this issue would still occur even if I was. Qt/Nokia have announced that they don’t expect to support Mac OS X 10.6 until they release Qt 4.6, whenever that might be. What use is a cross-platform toolkit that doesn’t support the latest major OSs?
Developer releases of 10.6 have been available for a while – I believe the Qt team should have burnt the midnight oil to make sure they had a release that properly supported 10.6 as soon as it became generally available. I know that isn’t easy given the size of the Qt framework and Apple’s penchant for secretiveness. But that is the game they are in and that is what I expect. I think they have seriously dropped the ball here, and this is coming from a longtime Qt fan-boy. Perhaps they have spread themselves a bit too thin by moving to LGPL licensing.
I have written this post as a quick heads up to other Qt developers. Thanks to everyone that helped me get this far.