Re: [Vala] Generating bindings for non-GLib/GObject based API

[Michael Wild <themiwi users sourceforge net>]

On 29. Apr, 2010, at 21:22 , Jan Hudec wrote:

> On Sun, Apr 25, 2010 at 11:46:17 +0200, Michael Wild wrote:
> > On 23. Apr, 2010, at 22:29 , Jan Hudec wrote:
> > > Actually I believe
> > >
> > >   [Compact]
> > >   [CCode (cname = "void", ...)]
> > >   class Thing ...
> > >
> > > should work. It will give you void * passed around, so it's some kind of
> > > pointer and C implicitly casts to and from void *, so no errors and no
> > > warnings.
> >
> > I don't think that I'd like that one particularly... I'd rather prefer to
> > use a Vala wrapper class then.
> >
> > > You can also just make it
> > >
> > >   [Compact]
> > >   [CCode (cname = "struct unknown_type", ...)]
> > >   class Thing ...
> > >
> > > with the real value for "unknown_type" from the library header. That will
> > > make the code more type-safe on the C side, but vala will check the types
> > > enough and it would be relying on something not officially documented.
> >
> > Unfortunately that's impossible. The official standard states that there is
> > a opaque type Thing, but nothing more. Every implementor is free to do as
> > he pleases... Some even typedef it to an integer handle.
>
> The void case would be OK if you knew it is always a pointer. But if it's
> a handle of any type, than you'll have to make it a "[SimpleType] struct"
> (SimpleType means it's passed by value).
>
> Than you can try whether setting a copy_function and destroy_function on
> a simple type will do what you need and otherwise you'll just have to wrap
> it in a normal vala object.

That's what I'm doing right now. I treat it as a SimpleType with no memory-management and then wrap it in a 
separate vala library.

Thanks for all the help

Michael