[Libguestfs] [PATCH] Non-working support for GObject Introspection.

[Daniel P. Berrange]

On Tue, Mar 16, 2010 at 03:45:17PM +0000, Richard W.M. Jones wrote:
> On Tue, Mar 16, 2010 at 02:53:29PM +0000, Daniel P. Berrange wrote:
> > GObject is the primary root object, but things don't neccessarily need
> > to inherit from GObject. Since you're trying to directly expose libguestfs'
> > own object(s) you'll probably need to register them as base types  using
> > the GType APIs. This section of the API docs gives a semi-useful intro to
> > GTypes
> > 
> >   http://library.gnome.org/devel/gobject/stable/chapter-gtype.html
> > 
> > Ultimately this comes down to a call to g_type_register_static()
> > 
> >   http://library.gnome.org/devel/gobject/stable/gobject-Type-Information.html#g-type-register-static
> > 
> > but it is not very well documented because 99% of apps just inherit
> > from GObject instead of introducing new base types like libguestfs
> > would need todo.
> 
> Unfortunately this doesn't work.  The handle (guestfs_h *) is wrapped
> inside a GType:
> 
> typedef struct _GuestfsH {
>   GObject parent;
>   guestfs_h *h;
> } GuestfsH;
> 
> I can now register this easily enough, but GObject won't automatically
> unpack that handle when it passes it to the other functions.  ie.  The
> other functions would receive a GuestfsH, instead of a guestfs_h *,
> and they won't know what to do with the former.

Oh I see - this struct is actually attempting to create a GObject subclass
containing a guestfs_h *. This definitely don't work, because of the 
mis-matched ptrs you mention. I thought you were registering 'guestfs_h *'
itself as the type without the 'struct _GuestfsH' wrapper. This avoids
GObject entirely introducing a new base type.  


Daniel
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