When tabbing into a radio button group with the middle of three radio buttons selected focus should be on the selected radio button, not the first or last (if shift tabbing) non-selected radio button.
Be aware of these issues:
- JDK-8033699, "Incorrect radio button behavior"
- JDK-8154043, "Fields not reachable anymore by tab-key, because of new tabbing behaviour of radio button groups."
- JDK-8158282, "[macosx] radio buttons have incorrect focus behavior"