Sometimes, I didn't remember what keys had I pressed, occasionally switched a text box to right-to-left layout. Well, maybe this is a very useful feature for Arabic users, but I just don't know how to switch back to left-to-right layout.
(P.S. In MS Windows, there's a text direction option in the right button menu for the text box. However, in Linux (GNOME Classic) I didn't see any.)
