Hi all, there is this issue report #4011 "Map canvas flickers when content is dragged" which is actually pretty annoying and doesn't get much attention. ( http://hub.qgis.org/issues/4011 ) I think the solution would be pretty simple. Please read on.
It was introduced by f4d26d6211830a866030a333236dcfbf15e077aa "Fix for resize crash, ticket #2714". This bugfix disables backbuffering, what fixes the crash but leads to the beforementioned flickering. The crash seems to be related to Qt versions (probably 4.6 and 4.7 affected). When I tried to reproduce the crash in 4.8.1 (by reverting abovementioned patch) I couldn't reproduce the crash. So it is well possible that this problem has been fixed in Qt upstreams. But: I myself never could reproduce this crash (due to the lack of a system with old Qt libs). So, I would be happy if someone familiar with this problem could confirm that this is fixed with Qt 4.8. Then there are two possibilities (unless you come up with a third one): 1. Check for qVersion upon every repaint as suggested by Martin Dobias and then enable/disable the workaround accordingly. 2. Switch the workaround on/off by a pre-compiler constant. This way, any new distro with Qt>=4.8 could be shipped without the workaround-code being compiled into the binaries. Any comments on this issue are very welcome, as it makes QGIS look a lot sweeter :) Regards _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
