M$ Windows has an ability for each window class to remember their own input/layout language. That way every app will receive keyboard input set/changed by the user on the fly. E.g. LO Writer will receive a native keyboard input and Konsole and all other apps a default English keyboard input. Surprisingly, I haven’t seen much demand for this particularly but it is useful.
As addendum, when AFK, I often forget that I have changed the current language(when in Firefox). Taskbar applet does not distinguish it enough. From the top of my head, it would be useful if Ibeem cursor image could change color when user change the language layout. That implementation would require setting multiple cursor themes for each language with a different Ibeem cursor image and change them on each switch. Now, cursor themes have been a problem with Linux from the age of time and doing it this way doesn’t appear as the best approach. Is there any fallback function that can force a theme to use different Ibeem image?
Oh, finally, and this have confused me a bit :), doublecliking a flag within settings page to change the textual representation of a current language layout is not very intuitive.