Main concept is to adding a focus-change mode, which is toggled by holding key, for example ALT. In focus-change mode, keyboard focus can be moved betwewn components by keyboard arrows, ang page-up/page-down keys.
Usage:
TraverseFocusSupport tfs = new TraverseFocusSupport();
tfs.install(frame);
For example see src/main/java/io/github/wayerr/ft/swing/Example.java