Re: JXTA for ObjC (was: Re: a simple program)

[Richard Frith-Macdonald]

On Friday, August 17, 2001, at 02:23 PM, Aurelien wrote:

> Le vendredi 17 août 2001, à 02:41, Richard Frith-Macdonald a écrit :
>
> > On Friday, August 17, 2001, at 11:27 AM, Aurelien wrote:
> I'm not sure I understand this very well. The front-end thus calls the 
> back-end's drawing routine and the back-end makes callbacks on the 
> front-end's event handling routines ? So the back-end is just an 
> abstract layer to the native OS ? I mean, do you have routines like 
> drawRect (), fillOval, and the like in the back-end, which in turn call 
> native routines to do it ?

Yes something like that ... for the xdps backend, the drawing primitives 
map pretty directly
to display postscript commands, while for the xgps backend the dps-like 
primitives are mapped
via a drawing engine to xlib commands.

> I wasn't talking GTK, but QT (but maybe it's roughly the same thing). I 
> was under the impression that the most unstable part of GNUstep's work 
> was the AppKit. I can understand that a not-for-profit effort trying to 
> create an entire GUI library with support for PostScript is a huge task 
> and could still take a while before it reaches maturity. My idea is, 
> provided we set aside the great benefit of having PostScript 
> everywhere, the use of QT would make GNUstep more readily useable. By 
> saying <quote>[...] It would gain a certain degree of stability 
> [...]</quote>, are you acknowledging these assumptions ?

I was meaning that a GTK app writen using the base library was likely to 
be more stable than a GTK
app without the base library - as that library provides a good framework 
for the non-gui parts of
the app.
While it's true that the GNUstep gui is much less stable than the base 
library, I'm not sure that
it's much less stable than (say) GTK.
I really know too little about QT to comment on that.

> > You could also use bundles to write different backends for the GNUstep 
> > gui, but the frontend would
> > impose a GNUstep look and feel - the backend would be handling only 
> > low-level operations.
>
> OK, thus we would have exactly the same application on each and every 
> platform (what you wish) ?

Yes.  At the moment, we have xdps and xgps bundles, for use on x-windows 
systems with and without
display postscript.

> > The frontend has something called NSInterfaceStyle, which can be used 
> > to change the look and feel,
> > but it requires you to actually implement the code to handle the new 
> > look and feel within the frontend
> > library, so it's not a great mechanism.
>
> If this was done with QT, which also has the ability to set the 
> interface style, this could be done once for all platforms. Pardon me 
> if I'm wrong, this wouldn't require to write anything for the back-end; 
> this again is already being done by QT.

IU think if you used QT, you wouldn't want to use the gui library at 
all, or you would use NSInterfaceStyle to
disable most of the gui library and replace it with QT objects.  Using 
QT objects would be a completely
different API/programming paradigm to the OpenStep AppKit ... so I think 
that trying to combine the two
would probably confuse things.

> > If you really want a totally different, native, look and feel
> > it makes more sense to omit the GNUstep gui and work with the native 
> > gui library directly.
>
> Yes, but that would force the developer to write a GUI/platform.
But that's just what things like QT and GTK are supposed to be - so you 
wouldn't need to write a new
gui platform.  OK, so they may be much less fully featured than the 
AppKit, but I think that's a
price you probably have to pay for using them.

> > PS. Just in case it's not already apparent ... I prefer to use the 
> > GNUstep look and feel on every
> > system rather than use native look and feel.  Even though Apples new 
> > MacOS-X is very pretty, I still
> > believe that the NeXTstep gui was (a little) prettier (look)  and (a 
> > lot) more usable (feel).
>
> Yes, but you cannot just bypass the fact that users are reluctant to 
> non-native l&f. I myself tend to consider a non-native application as 
> being amateurish, though I admit this is 100% irrational. Now, talking 
> personal tastes, I never had the chance to use a NeXT computer, but 
> from the screenshots you see on gnustep.org, pardon me, but it's making 
> me sick. In particular, the techy dark gray/black option is 
> frightening, really. But, again, when I'll have something compiled on 
> my Linux box, and used it a bit, maybe I'll change my mind...

True ... the great thing about free software is that people can write 
their own stuff ...
I'd like people to contribute native look and feel systems - but nobody 
(afaik) is working on thatm
and I'm not about to (though I may offer advice).