474440 - Deprecate -moz-user-focus and use something else for xul elements

Status: NEW

(Core :: XUL, defect)

Description

[Neil Deakin]

This property don't really belong in css. Currently, it only does anything for xul elements (although the code to check it is still run for all elements then the result is just ignored)

A focusable attribute for xul seems the logical choice, however there are two extra features that are needed:

1. a means for a widget to specify its default focusability. This would probably need a flag in the xbl of some sort.
2. a means for an area to have focusability disabled as a group. This is needed to disable focus for toolbar customization for instance, or to replace the hidden view checking for focus with a more direct approach.
 
The other -moz-user properties should be done in a similar way perhaps:

-moz-user-modify: contenteditable attribute can be used or an editable block of some sort
-moz-user-input: an odd one, indicates if an html element is enabled/disabled, but xul doesn't use it at all.
-moz-user-select: sort of makes text unselectable, but only in the sense that the mouse doesn't select it. The text can still be part of a selection if it is started outside the block (select all for instance)

Filing this bug to keep track, but needs more thought.

Comment 1

[Martijn Wargers (dead)]

I think Aaron removed the support for -moz-user-focus in html and used tabindex now, see discussion in bug 256003.
So maybe that could be used also for xul, for consistency?

Comment 2

[Robert Kaiser]

We have some focusable labels in a few places in XUL, e.g. .text-link or the ones I used in SeaMonkey's download progress windows so that one can get accessible context menus on source and target location labels. Using CSS for getting those really feels hacky, an attribute would fit better for such cases for sure (tabindex sounds hacky as well though, as one would need to adjust following indexes for every .text-link added somewhere, I guess).

Comment 3

[Dão Gottwald [:dao]]

text-link labels just need to be made focusable in one place. For XUL applications it's largely irrelevant where or how that's done.

Comment 4

[Firefox Bug Husbandry Bot]

Moving to Core:XUL per https://bugzilla.mozilla.org/show_bug.cgi?id=1455336