TraitsUI buggy view depending on OS

Question

I'm using TraitsUI in Python to create applications, and noticed that the UI disappears on a Mac 10.8, looks great on Ubuntu 10.04, and is somewhere in between for Ubuntu-Mate 14.04 (ie small view discrepancies)

This is using the latest version of traits=4.5.0 on both computers and traitsui=4.4.0. Any ideas, if not why this is happening, in which package or component of traits/traitsui the issue might reside?

Thanks.

PS the plot is not missing from the first screenshot, I just deleted it so that's not part of the bug.

Answer 1

Converting chat to answer:

The discrepancy was due to differences in installed GUI backend toolkit versions. There are two main backends available in TraitsUI: The newer Qt is more performant, OO, full-featured, and attractive, which is why it is the default within Canopy. The older Wx is still the default at the command line for legacy reasons. There are two wrappers for Qt: pyside and pyqt. We recommend and use pyside for licensing reasons (and provide it for free, unlike pyqt).

The backend can be specified either in code or by setting environment variables at the command line. See Toolkit Selection and Integrating in a Qt application and VTK/Mayavi on Mac OS X .