Strange behaviour of DataViewCtrl on OSX

I noticed a strange behvabiour of a DataViewCtrl on OSX 10.11, python3.7, wxpython 4.1.1a1. After notifying the DataViewModel that an item has been removed at some node, at all adjacent items the triangle symbol appears, indicating that the node is exapandable, which is not the case. This happens only when the DataViewCtrl has a single column. With two columns everything works as expected.

With the attached sample, click “Expand some” and then “Move”: item “three.element C” will be moved to “two”. Before move:

After move:

Now add a second column (“Add column”) and repeat the same.

I guess this is more a wxWidgets issue than a wxpython one. If you agree I will report it there as well.

Regards, Christian
osxbug.py (5.6 KB)

I was able to replicate this, but I don’t know what could cause it. You’re probably correct that it is a wxWidgets’ issue, so please do report it there.

Ok, I reported it over there but I was unable to create a c++ sample to demonstrate the issue. I modified the dataview sample but until now it behaves just fine.
I made one more observation with the python sample: it does not happen always. And when it happens, the IsContainer method of the model is not called. When trying it today it worked as expected. Then I resized the frame (after having expanded the source node) and the problem appeared again (and IsContainer was not called).

Christian