gdk:device-key (device index)

device -- a gdk:device object
index -- an unsigned integer with the index of the macro button to get
keyval -- an unsigned integer with the keyval to generate
modifiers -- a value of the gdk:modifier-type flags

If the index argument has a valid keyval, the gdk:device-key function will return keyval and modifiers with the keyval settings. The (setf gdk:device-key) function specifies the X key event to generate when a macro button of a device is pressed.