Re: Suggestion for improving backend configuration...

[Fred Kiefer]

I fully agree with you that dispatch based on strings is bad and having 
that done at compile time, either in this file or in some make file 
magik, is definitely the better solution.

What would you call the common parts of the backend? The gsc classes?
Moving these into a separate framework semms wrong to me, they either 
belong to gui (as part of NSGraphicContext) or into the backend itself. 
And at the tiem we made the split of gui and back the current interface 
seemed sensible to us, it still does for me.

What we are talking about here is somebody wanting to write a new 
backend, lets say from framebuffer, Wayland or CoreGraphics. I don't see 
anything stopping him or her to integrate this into the current back 
code. Doing so would help to share code between the different 
implementations. At least up to now it was the best way to handle that code.

Fred

On 28.06.2012 03:55, Gregory Casamento wrote:
> Fred,
>
> What I had thought is that the initializeBackend method could use
> information from the info.plist for the bundle to determine what the
> concrete subclass for the context and server are.  This would be trivial to
> implement.
>
> It seems to me that it should be possible to compile a backend without
> modifying the logic I quoted in the previous message.
>
> Wouldn't it be also better to build the common parts of the backend into a
> framework so that "third party" backends could be written without requiring
> direct changes to GNUstep code.
>
> This is just something I was thinking about that could be useful which is
> why I asked for thoughts regarding it.  It is not a fully formed idea, so
> there shouldn't be any puzzling over it, I was asking people to brainstorm
> a little with me.
>
> Later, GC
>
> On Wed, Jun 27, 2012 at 5:36 PM, Fred Kiefer <address@hidden> wrote:
> > On 27.06.2012 17:02, Gregory Casamento wrote:
> > > Guys, currently the code which configures the backend graphics context
> > > looks like this:
> > >
> > >    /* What backend context? */
> > >    if ([defs stringForKey: @"GSContext"])
> > >      context = [defs stringForKey: @"GSContext"];
> > >
> > >    if ([context isEqual: @"xdps"])
> > >      contextClass = NSClassFromString(@"NSDPSContext");
> > >    else if ([context isEqual: @"art"])
> > >      contextClass = NSClassFromString(@"ARTContext");
> > >    else if ([context isEqual: @"winlib"])
> > >      contextClass = NSClassFromString(@"WIN32Context");
> > >     else if ([context isEqual: @"cairo"])
> > >      contextClass = NSClassFromString(@"CairoContext");
> > >   else
> > >      contextClass = NSClassFromString(@"XGContext");
> > >
> > > I think that this information should come from the backend bundles
> > > plist if possible.  This way it's possible to create a backend without
> > > needing to modify backend code directly.
> > >
> > > Any thoughts?
> > >
> > > Later, GC
> >
> > Getting this information from the plist instead of hard coding the values
> > here is fine by me. But how would the correct value get into the plist and
> > how can you write a backend without touching the backend code?
> >
> > Completely puzzled,
> > Fred