A DESCRIPTION OF THE REQUEST :
Java AWT has MouseWheelListener for vertical scrolling and MouseListener for other button events. Please add specific support for horizontal scroll events. (There are several ways this could be done, e.g. an MouseHorizScrollListener interface or adding BUTTON_LEFT_SCROLL/BUTTON_RIGHT_SCROLL identifiers in MouseEvent, or smooth scrolling support which also translates non-smooth scroll events.)

JUSTIFICATION :
Because many hardware devices support horizontal scrolling and Linux supports reporting it in a fairly standard way, yet most Java applications I have used do not support horizontal scroll events.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
On Linux, XEV reports the main mouse buttons with codes 1-3, vertical scrolling as button events with codes 4-5, and horizontal scrolling similarly with codes 6-7. Applications should have a standard way of recognising and responding to these button events and scrolling horizontally.
ACTUAL -
Horizontal scroll events are ignored or misused (e.g. netbeans opens a right-click menu on any horizontal scroll action). The events *are* reported in a usable way, but there is a call for standardisation: see http://netbeans.org/bugzilla/show_bug.cgi?id=226785#c4 .

CUSTOMER SUBMITTED WORKAROUND :
See linked netbeans report.