Same Java app: Tab vs. Right arrow for moving to next radio button

[Jonathan Kamens]

We are trying to implement some automation with a third-party app via 
using "xdotool" to send X events to the app.

One of the things we need to do with the app is to switch focus from one 
radio button to another.

When we run the app on Ubuntu 14 (Unity desktop), the tab key can be 
used to switch to the next radio button, and the right arrow can /not/ 
be used. In contrast, when we run the app on Fedora 21 (GNOME 3 
desktop), the right arrow key can be used and the tab key can /not/ be 
used. When I say "can not be used," I mean it does nothing.

We're using openjdk 8 in both cases. I observed the same behavior, at 
least the Ubuntu half of it, in openjdk 7 as well.

Since it's exactly the same app in both cases, it seems unlikely that 
it's the app that's responsible for the difference in behavior between 
the two platforms, which is why I'm coming here first to ask about it 
rather than going to the author of the app.

Any insights anyone can offer into why the two platforms behave 
differently and what we can do to make them behave the same would be 
greatly appreciated.

Thanks,

Jonathan Kamens