Re: Cocoa To GnuStep port questions

[Pedro Ivo Andrade Tavares]

At 09:38 11/3/2002, Saibot wrote:
> We are
> going to check how GnuStep can help in making the port from Mac OS X to
> windows and linux easier, and if we consider it the way to go, probably
> allocate part of our time in coding for 
> GnuStep.

First of all, thanks for considering the port using GNUstep. I hope you
will find it useful; please tell us what problems you find; we can always
use more suggestions for improvement.

> I am
> not really familiar with NextStep, only with Cocoa, so if my questions
> appear stupid, please forgive...

NextStep and OpenStep are similar things, but not the same. OpenStep the
operating system could be considered "NeXTStep 4.0", just like
MacOS X is "NeXTStep 6.0" (MacOSXServer used to identify itself
on uname as rhapsody-5.1, IIRC). NeXTStep the API, however, is mostly
dead, having been replaced by OpenStep, Cocoa's forefather.

GNUStep tries to comply both to OpenStep and Cocoa definitions, but not
NeXTStep.

> My
> questions are the following:
>  
> - Did any of you already try to use a gcc
> modified with the apple patches to compile ObjC++ code that can run on
> windows/linux. I don't really care whether anyone but me uses the
> compiler as long as it generates code that performs the task on these 2
> platforms as well as on OS X. So, the patches being accepted into the
> mainstream gcc are not something I really care
> about.

When Apple first made available its ObjC++ compiler as source, I tried to
compile it on Linux. At the time, the source was in a really bad shape
for porters, with plenty of MacOSX-specific code sprinkled throughout it
without care. I never got it to produce a working compiler.

However, that was when the Apple compiler was a severely hacked version
of gcc 2.7.2. Stan Shebs of Apple has been working for the last few years
on the Apple cc code, to bring it closer to the mainlne gcc. I believe
the Apple version of gcc 3.0 or gcc 2.95 will compile a lot more cleanly
on Linux. Whether it will provide a working executable, I don't
know.

Well, this tickles my curiosity... I'll try building Apple gcc3.1 from
cvs on Linux, and I'll keep you posted on what happens in a day or
two.

>  -
> Does the GnuStep implementation of NextStep support anti-aliasing and
> floating point coordinates for drawing.
>  
> - How does a GnuStep program compare to a
> Cocoa application in terms of performance? (it is obviously hardware
> dependant, but an approximation will do me
> fine).

I believe you will find on the mail archives a recent conversation
pointing out that classes such as NSArray are vastly faster on GNUstep
than on Cocoa Foundation. However, no such comparison has ever been made
on the GUI side of things, and it's possible that it is in need of
optimization.

> - Is
> GnuStep closer to NextStep in implementation or to Cocoa when
> implementations differ?

GNUstep tries to comply to both OpenStep and Cocoa. When there are
differences, the #defines STRICT_OPENSTEP and STRICT_MACOSX try to
"steer" it. For example, you could #define STRICT_MACOSX to try
to get as close as possible to Cocoa.

> - Does
> GnuStep work on windows (I saw some notes about it on the website but
> couldn't figure out whether it actually works or not, especially since
> there is an item mentioning "port GUI to
> windows").

As it has been already mentioned, the base library is working, but the
GUI library is still to be ported to Windows.

> - Does
> (or will) a widget (for instance, a NSButton) look the same on windows
> and linux or do they each rely on the "typical" widget
> appearance of the OS it runs on?

On Linux, it will have a NeXTStep/OpenStep (the OS) look; on Windows, it
will depend on the taste of whoever writes the GUI backend, as it's not
working yet ;)

Good luck to you,
Pedro Ivo Tavares