Comment 23 for bug 58693

Bottom Line
==========
There are multiple bugs w/r to keyboard events in Firefox on Linux.

Background
==========
JavaScript events have attributes. Mozilla currently does the following for key and text events:

(1) Assigns values to the attribute keyCode for keyup and keydown events. The assignment is often wrong (null) on Linux.
(2) Assigns values to the attribute charCode for keypress events. The assignment is often wrong (null) on Linux.
(3) Bungles the assignment of attributes to compositionstart and compositionend on Linux

The W3C specification declines to specify what the correct values are for assignments to charCode and keyCode. It makes recommendations for the assignment of two new attributes: char and key. In principal,
these assignments could be made more less operating system and browser independent.

(4) Firefox does not make assignments to either of the new char or key attributes. In the tables below, no attempt is made to indicate the lack of assignment. Assignment of both char and key look relatively easy. The previous draft of the W3C DOM Level 3 Events specification was more challenging.

(5) Firefox dispatches compositionstart and compositionend events on Linux. On Windows the behavior is completely different. This is an OS dependency that is difficult to code around.

(6) W3C calls for a textInput event to get fired after the last keyup. If Firefox implemented this part of the spec then the OS-dependency and browser-dependency it's current implementation is requiring could be made to vanish -- at least for the majority of the applications that listen to the keyboard.

In an earlier post on this topic, operating system inconsistencies had not been determined. Now they are and they are large.

Supporting Data
===============

Mozilla key and text event sequences
Firefox 3.6.10
Test URL: https://bug447757.bugzilla.mozilla.org/attachment.cgi?id=474270

Nominal keyboard sequence (Windows: AltGr 2 e)
Country: Albania
Language: Albania

The tables record the event sequence in the order of occurence.

Windows
=======
keyC charC alt event
17 - F keydown
18 - T keydown
50 - T keydown
50 - T keyup
17 - T keyup
69 - F keydown
- 283 F keypress
69 - F keyup

Linux
=====
keyCcharC alt event
0 - F keydown
- 0 T keypress
0 - T keyup
0 - T keyup
- - T compositionstart
- - F compositionend
69 - F keyup