Re: 2 questions about Application Services, 1 about backend

[Xavier Glattard]

David Ayers a écrit :
> Am Freitag, den 20.02.2009, 11:18 +0100 schrieb Xavier Glattard:
>
> > > ** 3. How can I check at runtime if a function is implemented by the 
> > > platform backend ?
> > > For example "setValues" is not implemented on win32:
> > >  [[self openGLContext] setValues:&swapInterval 
> > > forParameter:NSOpenGLCPSwapInterval];
> > A call to a non-implemented method raises an exception. You may catch 
> > it. As it's only implemented by Apple a compile time check should do the 
> > job. But is this what you need ?
>
> -resondsToSelector: is the canonical run time check.
>
> id ctx = [self openGLContext];
> if ([ctx respondsToSelector:@selector(setValues:forParameter:)])
>   {
>     [ctx setValues:&swapInterval forParameter:NSOpenGLCPSwapInterval];
>   }
>
> Cheers,
> David

Yes but [setValues:forParameter] is implemented as:
   '[self notImplemented]'

So '[respondsToSelector:@selector(setValues:forParameter:)]' will always
return YES, and [setValues:forParameter] always raises an exception.

Regards
- Xavier