How to enable horizontal scrolling with 3-buttons mouse

You may have a 3 buttons mouse with vertical scroll, but no physical horizontal scroll.

Here is how to have horizontal scroll emulation using SHIFT + vertical scroll.

Installation

First install those two packages from source:

 sudo spi -i xbindkeys xautomation

• xbindkeys will be use to do an action of specific events (here shift + vertical scroll).
• xautomation will be use to generate the horizontal scroll events for X.

Configuration

Vertical scrolling is seen as two buttons by X, by default it's button 4 and 5. (1 is left, 2 is right, 3 is middle) Horizontal scrolling is also seen as two buttons', 6 and 7 by default.

So the idea is, for each SHIFT + button 4, a button 6 event should be generated. The same for button 5 and 7.

Create the file ~/.xbindkeysrc.scm with the following content:

 ; bind shift + vertical scroll to horizontal scroll events
 (xbindkey '(shift "b:4") "xte 'mouseclick 6'")
 (xbindkey '(shift "b:5") "xte 'mouseclick 7'")

Then create the file '~/.config/autostart/xbindkeys.desktop with the following content:

 [Desktop Entry]
 Encoding=UTF-8
 Version=1.0
 Type=Application
 Name=xbindkeys
 Exec=xbindkeys

This will run xbindkeys on every desktop login. You can run xbindkeys directly to have it work right now.

Firefox

For this to work in Firefox too, you have to disable the action bound to shift+scroll which do back and forward action per default.

Go to about:config, search the key mousewheel.with_shift.action and assign it the value -1.