Bindings without callbacks (was Re: [ANN] Squeak bindings for D-Bus)

[Daniel B. Faken]

On Wed, 25 May 2005, John (J5) Palmieri wrote:
> One note.  It is not the best thing to patch dbus in order to support
> your bindings.  What you probably want to do is create a helper library
> that your bindings then link to.

Yeah.. it just seemed like an awfully small library (~20 lines of C) :).

Can you think of any better way to go about this?

The code in question:
------------------------
// Helper function for Squeak bindings

#include <stdio.h>

static DBusHandlerResult _dbusMessageHolderHandler(DBusConnection *conn, 
DBusMessage *msg, void *data)
{
  _dbus_assert(conn && msg && data);
  dbus_message_ref(msg);  // needed?

  *((void **)data) = msg;

  return DBUS_HANDLER_RESULT_HANDLED;
}
DBusObjectPathVTable *dbus_message_holder_vtable(void);

DBusObjectPathVTable *dbus_message_holder_vtable(void)
{
  static DBusObjectPathVTable tbl;

  tbl.unregister_function = NULL;
  tbl.message_function = _dbusMessageHolderHandler;

  return (&tbl);
}
------------------
(actually I don't even need the latter part (to get the vtable) - just the 
callback fn, since I don't know a way to dynamically generate these)

This allows the application (here: Squeak) to register a fallback 
(/Squeak) with the result of calling dbus_message_holder_vtable() and a 
data pointer-pointer.
  The app can then call dbus_connection_read_write_dispatch() or
dbus_connection_dispatch() and check the pointer afterwards to see
if it got a message.

thanks,
Daniel

 
> On Tue, 2005-05-24 at 14:50 -0400, Daniel B. Faken wrote:
> > Hello all,
> > 
> >   I've put up a first version of my Squeak-Smalltalk bindings to the D-Bus 
> > IPC system at: http://www.ccv.brown.edu/~faken/squeak/DBus-0.1.1.cs
> > 
> >   This is an alpha release; it has some documentation but no examples yet.
> > 
> >   Feedback is welcome..
> > 
> > thanks,
> > Daniel Faken
> > 
> > P.S. there is kindof an example at 
> > http://lists.freedesktop.org/archives/dbus/2005-May/002657.html
> > for the die-hard. :)
> > 
>