Re: UIKit?

[David Chisnall]

On 2 Jan 2010, at 16:53, hns@computer.org wrote:

> Unfortunately, it isn't. The main reason is that iPhone Apps don't use
> GUI (AppKit) but UIKit (which is similar but more a cousin than a
> twin) and heavily rely on CoreGraphics, CoreAnimation and OpenGL-ES.
> Neither API is available through GNUstep or mySTEP.

Not true.  We have Opal, currently in Étoilé svn, which is an  
implementation of CoreGraphics.  Gregory was getting the original  
author to sign copyright assignment so that we could move it upstream  
to GNUstep, but I'm not sure what the status of this is.

Eric has been working on this over Christmas and has now implemented  
things like CGLayer, which is used to implement the low-level bits of  
CoreAnimation.  He's also been working on making -gui issue GC* calls  
instead of DPS* calls, so that we can use Opal for drawing and just  
leave -back handling window creation and event generation (something  
we discussed with Fred at the Étoilé hackathon last spring).

If this is completed and merged then we will be in a good place to  
implement CoreAnimation in -gui and implement UIKit.

OpenGL-ES is supported by Gallium3D and should show up in X.org soon.

> So what are your ideas/plans? Should we start working on it? Who would
> be interested in using it and developing?

I've not looked at UIKit in great detail, but it did seem very similar  
to AppKit when I did look at it.  I think we should be able to reuse a  
lot of the code from out AppKit into a new UIKit.  A few things are  
not used at all by UIKit (e.g. NSCell), but UIKit and AppKit are very  
similar in other places.

It would be really great if we could port iPhone apps to other  
platforms with GNUstep, so this is something I'd be interested in  
seeing, but at the moment it's not high up my list of priorities to  
work on.

Note that UIKit makes heavy use of ObjC2, so any implementation will  
almost certainly need to use clang and libobjc2, both of which are  
close to being release-ready but need testing.  I'm now using both for  
Étoilé development, but no one outside of Étoilé has sent me any  
testing results from libobjc2 and I've only had one clang bug filed  
for ObjC code generation (by someone who isn't using GNUstep at all,  
in fact, related to nested @try statements and now fixed).

David

-- Sent from my brain