[Feature request] Keyboard shortcut to switch languages in panel

[tempuserr]

It would be very convenient to have a keyboard shortcut to switch translate direction (e.g. german->english to english->german) in panel.

Maybe Alt-T again? Because Alt-T is not used at all to hide translation panel.

So it would work like this: first Alt-T - show translation panel second Alt-T (in panel) - switch languages third Alt-T (in panel) - switch languages back and so on.