My Input Method configuration

10-evdev.conf

#       - - - Logitech Marble Mouse Settings - - -
#
#       The Logitech Marble Mouse buttons are mapped [A-D] from left to right: 
#       A (large); B (small) |  C (small); D (large). 
#
#       Preferred options for right-handed usage:
#       A = normal click [1]  
#       B = middle-click [2] 
#       C = middle-click [2] 
#       D = right-click [3]
#       Hold button B while rolling trackball to emulate wheel-scrolling. 
#
#       Preferred options for left-handed usage:
#       A = right-click [3]  
#       B = middle-click [2] 
#       C = middle-click [2]
#       D = normal click [1]
#       Hold button C while rolling trackball to emulate wheel-scrolling.
#       Pressing both large buttons simultaneously (b) produces a "back" action.

Section "InputClass"
        Identifier  "Marble Mouse"
        MatchProduct "Logitech USB Trackball"
        MatchIsPointer "on"
        MatchDevicePath "/dev/input/event*"
        Driver "evdev"

#       Physical button #s:     A b D - - - - B C    
#       Option "ButtonMapping" "1 8 3 4 5 6 7 2 2"   right-hand placement
#       Option "ButtonMapping" "3 8 1 4 5 6 7 2 2"   left-hand placement
#       b = A & D 
        Option "ButtonMapping" "1 8 3 4 5 6 7 2 2"

#       EmulateWheel: Use Marble Mouse trackball as mouse wheel 
#       Factory Default: 8; Use 9 for right side small button
        Option "EmulateWheel" "true"
        Option "EmulateWheelButton" "8"

#       EmulateWheelInertia: How far (in pixels) the pointer must move to
#       generate button press/release events in wheel emulation mode.
#       Factory Default: 50
        Option "EmulateWheelInertia" "10"

#       Axis Mapping: Enable vertical [ZAxis] and horizontal [XAxis] scrolling
        Option "ZAxisMapping" "4 5"
        Option "XAxisMapping" "6 7"

#       Emulate3Buttons: Required to interpret simultaneous press of two large
#       buttons, A & D, as a seperate command, b.
#       Factory Default: true
        Option "Emulate3Buttons" "true"
EndSection

Section "InputClass"
    Identifier            "Keyboard Defaults"
    MatchIsKeyboard       "yes"
    Option                "XkbLayout" "de" # German keyboard
    Option                "XkbVariant" "alt-intl,nodeadkeys"
    Option                "XkbOptions" "compose:paus"
EndSection