Common ModemManager.h

[Aleksander Morgado <aleksander lanedo com>]

Hi everyone,

One of the things that came up during the NM/MM BoF during the Desktop
Summit was about the possibility of having a C library (libmm-glib? [1])
which will enable easy access to ModemManager info in GLib-based
applications.

I'm looking into preparing a "ModemManager.h" with common types and
symbols, so that the daemon, the new libmm-glib library and the
additional users of the DBus API can all use it. This approach is
already being used in NetworkManager (if I'm not mistaken), which
exposes a "NetworkManager.h" header file (not auto-generated),
containing symbols and types used by the daemon and libnm-glib.

Currently, in ModemManager we auto-generate the header for the C-based
DBus clients in "include/mm-modem.h", but the daemon itself doesn't use
it. This header is generated applying a XSLT to the DBus XML APIs under
introspection/, but for example doesn't define enum types, just #defines
for every symbol. For the C-based user of the DBus API, these defines
are possibly enough, but it would be great to instead get proper enum
types which can be used both internally in the daemon and externally in
the libmm-glib API. A common header for all the types will help in
avoiding the need for updating internal enums and external enums in
different places.

Another option would be to get libmm-glib re-define all the types using
a library-specific prefix (e.g, "LmmModemState" vs "MMModemState"), but
I don't think that rewriting the same types in three different places
makes much sense...

So, what about having a common "ModemManager.h", and making the daemon
use it as well? I have mixed feelings on whether it makes sense to have
it auto-generated from the DBus API XMLs, anyway, as we want it to be
used also internally; so I would propose to have it manually maintained,
just as "NetworkManager.h"

Comments?


[1] WIP in the 'libmm' branch in the following git repo, right now using
gdbus and the stable DBus API:
git://gitorious.org/aleksander/modemmanager.git

-- 
Aleksander