Re: about RunLoop, joystick support and so on

[Richard Frith-Macdonald]

On 14 Feb 2007, at 16:56, Xavier Glattard wrote:

> That's OK ... but there is no practical pressure to be able to use
> > the backend indepedently of the gui, so I don't think you *have* to
> > take that view.
> > I'm perfectly happy with avoiding calls from back to gui methods ...
> > but that does involve changing the interface to pass more information
> > in both directions,
>
> Which one ?

The GSDisplayServer API is used for calls from the gui to the  
backend ... so it would be primarily this one, needing supply more  
parameters for some calls and perhaps return more information back in  
some calls.
In addition, the backend provides information in the form of events  
in the event queue, and perhps some special events not defined in  
Openstep/Cocoa might need to be added to the event queue.  I suppose  
the backend could provide notifications (NSNotification) if there is  
anything which needs to be sent  out-of-band (ie not as an event in  
the event queue)

> I think that would not involve so much changes. Calls from back to gui
> are not so numerous, some are simply bad (most in the win32  
> backend, like the
> use of Notification from the AppKit; i saw a [window sendEvent:  
> ev] ; some
> AppKit classes are 'categorized' to change methods!!), many others  
> can be easily
> change to an other form (the use of an alert panel), and some other  
> should be in
> the AppKit (window level management in the x11 backend (ignore  
> under win32),
> getNextEventMatching because AppKit and user events should not be  
> handle by the
> backend)...
>
> The more i see the win32 backend, the more i think it needs a deep  
> cleaning!
>
> > and since nobody (afaik) wants to use back standalone,
>
> I do :-)
> Well.. i would like.
>
> > there seems little to be gained by adding to the
> > interface rather than using existing gui api.
>
> Some month ago I thought of a SDL backend. But such a backend would be
> a subset of the official backend (only ONE window) : the full AppKit
> would not run with a SDL backend. For instance i would have to write
> my own SDLApplication class. But the official backend does need
> NSApplication, and Panel, and Menu... So my SDLApplication would
> not run with an offical backend!
> At end, the work would never be compatible with GNUstep in any way.

Well, I doubt that anyone would complain if you wanted to clean-up  
the gui<->back interaction as long as you approached it incrementally  
(cleaning up a bit at a time), so that if anyone spotted a problem we  
could revert easily.  Generally people are very willing to accept  
patches/improvements to GNUstep as long as they are not presented  
with big changes effecting lots of code in one patch (since such  
patches are very difficult to evaluate quickly).

Even if nobody else wants to use the backend the way you do, a  
cleanup/simplification would benefit everyone in future.