[GUI] State, Attributes and Some basic widgets

[Glynn Clements]

Alastair Reid wrote:

> Having the type system detect use of unsupported attributes is highly
> desirable

The main problem which I see with that is that the portability
constraint would dictate that you either:

a) only support those attributes which exist on all platforms (which
may only be a small subset of the attributes which exist on any given
platform), or

b) support all of the attributes which exist on any platform, and
ignore any which don't exist on the platform in use (which undermines
the purpose of using type checks).

A more viable approach might be to use type checks with regard to
state attributes, but not for stylistic attributes.

BTW, there is a side issue in that the complete set of attributes
might only be known at run time. This would be most relevent to an
Athena backend, as there are a lot of "enhanced" Athena replacements
(Xaw3d, Xaw-Xpm, Xaw95 etc) which have additional attributes which
aren't present in the standard[1] Athena library.

[1] Actually, "standard" is rather vague, as the XFree86 version
includes enhancements which aren't in the Open Group version, and you
could probably get a decent flame-war from the question of whether
XFree86 or The Open Group constitutes the "standard".

-- 
Glynn Clements <glynn.clements@virgin.net>