Re: [orbitcpp-list] Re: cpp branch: CORBA_Object struct hidden?

[murrayc t-online de (Murray Cumming)]

On Tue, 2002-02-19 at 10:04, Michael Meeks wrote:
> Hi Murray,
> 
> On Tue, 2002-02-19 at 09:04, Murray Cumming wrote:
> > 1. If a C++ class inherits from a struct, then it would make that struct
> > public to anybody who uses the C++ class.
> 
> 	You don't need to inherit anything public from it. Just some internal
> structures eg.
> 
> typedef struct {
> 	CORBA_Object_type base;
> 	gpointer cpp_impl_pointer;
> } ORBitCppInternalStruct;


So CORBA::Object would inherit from ORBITCppInternalStruct? Then I don't
see the purpose of cpp_impl_pointer, and I don't see how this is
different than having the CORBA_Object as a member field instead of
inheriting.

> > 2. We seem to need the CORBA_Object to be a member rather than a base
> > class, to allow for wrapping of existing CORBA_Object instances.
> 
> 	Hmm; true - then again that can most likely be achieved by either a)
> having an accessor method or b) keeping a CORBA_Object pointer that you
> use for this purpose on the C++ wrapper, and simply narrowing that
> inside the C++ impl. to ORBitCppInternalStruct.

There's no publicness problem in having the CORBA_Object as a member. 

The current problem is that there is no way to get an already existing
C++ wrapper instance from a C CORBA_Object instance. It's the lack of a
g_object_set_qdata() as mentioned in another thread.

Maybe there's a better way to do this. After all, how would a Perl or
Python binding libbonobo binding create a Perl/Python stub for an
existing C CORBA_Object instance? For instance, is there any kind of
instance ID? Can I create a 2nd CORBA_Object stub instance for the same
BonoboWindow?

-- 
Murray Cumming
murrayc@usa.net
www.murrayc.com