Configuring Kensington Slimblade in Linux

Question

I just got a Kensigton Slimblade Trackball and I'm trying to configure it. I'm adapting it from my old Logitech Marble configuration.

I want the configuration to be:

• Left-Bottom: Left click
• Left-Top: Backward
• Right-Top: Right click and ball scroll lock
• Right-Bottom: Middle click

The configuration I could set until now is:

• Left-Bottom: Left click
• Left-Top: Middle click
• Right-Top: Right click and ball scroll lock
• Right-Bottom: Backward

This is my configuration script:

xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Middle Button Emulation" 8 1   

xinput set-button-map "Kensington Kensington Slimblade Trackball" 1 2 8 4 5 6 7 

xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation" 8 1
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation Button" 8 8
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation Axes" 8 6 7 4 5
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation Timeout" 16 300

Before running this script, xev reports button numbers as:

Left-Bottom: 1, Left-Top: 2, Right-Top: 8, Right-Botom: 3

After running this script:

Left-Bottom: 1, Left-Top: 2, Right-Top: 8, Right-Botom: 8

So AFAIK, xinput set-button-map changes button order. In this page, I learned that the 2nd value corresponds to the middle mouse button, and the 8th to the Thumb1 (normally related to backward function). So I thought I should just use number 3 as the 2nd element and 2 as the 8th element like this:

xinput set-button-map "Kensington Kensington Slimblade Trackball" 1 3 8 4 5 6 7 2

but now the top-left button has right-click function and left-bottom is disabled. xev now reports

Left-Bottom: 1, Left-Top: 3, Right-Top: 2, Right-Botom: 8. 

Anyone knows how I set the configuration as I intend ? I'm using Ubuntu 16.04. Thanks.

Answer 1

A few minutes after I post the question I found the answer. Here goes in case anyone needs it (configuration for Mint 18/Ubuntu 16.04):

xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Middle Button Emulation" 8 0
7 8 9 
xinput set-button-map "Kensington Kensington Slimblade Trackball" 1 8 2 4 5 6 7 3 2
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation" 8 1
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation Button" 8 8
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation Axes" 8 6 7 4 5
xinput set-int-prop "Kensington Kensington Slimblade Trackball" "Evdev Wheel Emulation Timeout" 16 300

Edit

After upgrading for Mint 19 (at home) and Ubuntu 18.04 (at office) I found the configuration above doesn't work. 18.04 uses a different library for these kind of devices (libinput) and even if I reinstalled Evdev some options don't work. After a painful search I found the solution. Create a a file with .conf extension in /usr/share/X11/xorg.conf.d/ folder. In my case I named it 10-slimblade.conf. Put this configuration inside the file:

Section "InputClass"
        Identifier "Kensington Kensington Slimblade Trackball"
        MatchProduct "Kensington Kensington Slimblade Trackball"
        MatchIsPointer "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "ButtonMapping" "1 8 2 4 5 6 7 3 2"
        Option "ScrollButton" "8"
        Option "ScrollMethod" "button"
        Option "MiddleEmulation" "on"
EndSection

Restart session, and that's it.

Answer 2

Thanks so much! Just to add on a bit, I was able to find that these are how the buttons are on the trackball:

---------
| 2 | 8 |
---------
| 1 | 3 |
---------

And this is the order they are in the ButtonMapping string:

LeftClick MiddleClick RightClick ScrollUp ScrollDown ScrollLeft ScrollRight Back Forward

So, for me, I just wanted right and left on the bottom row, with back top left and middle top right:

Section "InputClass"
    Identifier "Kensington Kensington Slimblade Trackball"
    MatchProduct "Kensington Kensington Slimblade Trackball"
    MatchIsPointer "on"
    MatchDevicePath "/dev/input/event*"
    Driver "libinput"
    Option "ButtonMapping" "1 8 3 4 5 6 7 2 9"
    Option "ScrollButton" "8"
    Option "ScrollMethod" "button"
EndSection

The documentation here is non-existent, so this is what I could piece together by running xev -event mouse.

---

Here is a map from button ID to its function:

Button	Function
1	left click
2	middle click
3	right click
4	scroll up
5	scroll down
6	scroll left
7	scroll right
8	back
9	forward

Answer 3

Beautiful, thanks guys! :) Had to modify slightly to make it work for me, though. Since on my system (Ubuntu 18.04) xinput reports the trackball like this:

$ xinput list | grep Kensington
⎜   ↳ Kensington Slimblade Trackball            id=14   [slave  pointer  (2)]

I had to modify MatchProduct from your examples above to make that work for me. Also I slimmed it down a tiny bit. On my end it looks like this and that worked for me:

Section "InputClass"
    Identifier "My Kensington Slimblade Trackball"
    MatchProduct "Kensington Slimblade Trackball"
    Option "ButtonMapping" "1 8 3 4 5 6 7 2 9"
    Option "ScrollButton" "8"
    Option "ScrollMethod" "button"
EndSection