You would set a comma separated list of the keyboard layouts and define a key combination to toggle between them
in Xorg's config file as
Code:
Section "InputDevice"
Identifier "Keyboard1"
Driver "kbd"
....
Option "XkbLayout" "af,us"
Option "XkbOptions" "grp:alt_shift_toggle"
...
Alternatively at runtime
Code:
setxkbmap -rules xorg -model {the one in the xorg.conf, presumaby pc105} \
-layout "af.us" -option "grp:alt_shift_toggle"
Alternatively in the Window Manager, either configuration files , or applets or desklets or settings they provide