From: blimoges@sobeco.com (Bertrand Limoges)
Subject: Re: XVT toolkit??
Organization: Sobeco Ernst & Young
Date: Wed, 11 Nov 1992 16:16:18 GMT
Followup-To: comp.windows.x,comp.windows.x.motif,comp.windows.misc,comp.sys.misc,comp.sys.mac.misc,comp.unix.misc

In article <BxCptF.Jw1@world.std.com>, kevyn@world.std.com (Kevyn Ford)
wrote:
> 
> 
> > I would like inputs from anyone who has used the XVT Portability Toolkit.
> 
> One of my projects evaluated the XVT Toolkit against using the native GUI
> for our VAXstations ... as far as producing a portable GUI application XVT
> is fairly good.
> 
> However, while there wasn't any one problem that we encountered with XVT, it
> is not as robust as the native GUI system (which is to be expected) and we
> found that there were many "small" features lacking that, all together, gave
> the application an "unfinished" look (you can actually see some of this in
> their XVT-Design tool itself -- which is brain-dead).
> 
> We have found that XVT is more suited for "simpler" interfaces, and it will be
> used as such, but for one particular application we've decided to use the
> DECwindows/Motif interface.
> 
> In short, XVT is a good portable GUI system for apps that don't really need
> anything more than a few pull-down menus and graphical controls.

I've been using XVT for almost a year now, and I must say that it is
suitable
for applications that have much more than "a few pull-down menus and
graphical
controls". Let's first address the issue the original poster was concerned
about: portability between Motif, Mac, and OS/2 PM (very dissimilar GUI's).
Well
I must say that XVT does allow you to support these platforms, and if you
know
one of them well, it will be no problem to learn the XVT API, and it beats
learning Mac, Windows, PM, Motif, OpenLook, ... Incidently, I started from
a sound knowledge of the Mac toolbox, and worked from there.

That is not to say that XVT is without problems. As you may guess, any API
which promises to be portable between so many platforms has to adopt
somewhat of a common denominator approach, which means that all native GUI
features are not implemented within the XVT API. The main problem with that
is not really loss of functionality, but rather loss of adherence to the
standard human interface for that platform. However, note that you can use
any feature of the native GUI in a non-portable way, and these can be
coded in separate modules to minimize the mixing of portable and
non-portable
code. BTW, I run some XVT applications on a MacSE, and performance is more
than acceptable.

XVT does have several problems. 	It's a product in full evolution, and you
have to contend with some bugs. However the XVT technical help is very
good, bug reports are released, and bug fixes are shipped regularly. A lot
was cleaned up between version 2 and version 3, and you have to look at
where the product is going. Higher level API's built on top of XVT are
already available, and OO application framework (a la MacApp) are in the
pipes. I have had some frustrations migrating from the rich Mac toolbox to
the XVT API, but it makes me smile everytime I take that code from my Mac,
and just compile away on our RS6000 with Motif.

I could say more about the pros and cons of XVT, but my "baud rate" at the
keyboard, and net bandwidth precludes it.

Bertrand Limoges, Sobeco Ernst & Young Inc., Montreal, Canada

My opinions, not those of my employer.
---
We extend and amplify impoverished data on the basis of what we know about
how
the world typically behaves, and the result is that prejudice becomes a
natural part of "rational" thought.     --Jeremy Campbell
Newsgroups: comp.windows.x