[GUI] State, Attributes and Some basic widgets

Axel Simon A.Simon@ukc.ac.uk
Wed, 16 Apr 2003 12:23:45 +0100


On Wed, Apr 16, 2003 at 10:12:00AM +0100, Alastair Reid wrote:
> Glynn Clements <glynn.clements@virgin.net> writes:
> > 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 [...]
> > b) support all of the attributes which exist on any platform, [...]
> 
> This is a portability issue.
> 
> We can deal with portability issues through static checks (e.g.,
> typesystem) or dynamic checks which either lead to problems being
> ignored or are flagged as runtime errors but, whatever we do, we still
> have to tackle the portability issue.

Actually, I thought CGA is just saying what each GUI backend contains.  
Each backend implementor would just copy the classes specified in the CGA
and add members to it if necessary. CGA is just a specification, not a
library you link to. You just have the guarantee as a user that if you 
program does link against CGA, it will link and run against any other 
backend.

Axel.