Turn all ID param specs into object param specs (e.g. GimpParamImageID
becomes GimpParamImage) and convert between IDs and objects in
gimpgpparams.c directly above the the wire protocol, so all of app/,
libgimp/ and plug-ins/ can deal directly with objects down to the
lowest level and not care about IDs.
Use the actual object param specs for procedure arguments and return
values again instead of a plain g_param_spec_object() and bring back
the none_ok parameter.
This implies changing the PDB type checking functions to work on pure
integers instead of IDs (one can't check whether object creation is
possible if performing that check requires the object to already
exist).
For example gimp_foo_is_valid() becomes gimp_foo_id_is_valid() and is
not involved in automatic object creation magic at the protocol
level. Added wrappers which still say gimp_foo_is_valid() and take the
respective objects.
Adapted all code, and it all becomes nicer and less convoluted, even
the generated PDB wrappers in app/ and libgimp/.
This means that images' ownership is not given to caller in particular.
libgimp will now keep a reference of all GimpImage-s it creates and
return this same reference if called again. It also means that you can
now compare images by pointer comparison (as 2 GimpImage objects
representing the same image ID will be equal).
Obviously as a side effect, gimp_image_list() is changed to (transfer
container) as you must only free the container now, not the elements.
Also various other functions creating new images are now (transfer none)
too.
Long-time plug-ins will have to be taken in consideration in a further
step (we currently never free GimpImage for destroyed images in
particular).
No need of is_id_arg() anymore in pdb/lib.pl. Let's reuse the {id}
value. Also I had to add an additional trick for GimpDisplay which we
will now generate as such in libgimp PDB files, but still need to show
as GimpObject on app/pdb/.
As previously, only the new classes and the PDB generation for a first
step.
This means that all functions which were returning or taking as
parameter an image id (as gint32) are now taking a GimpImage object
instead.
The PDB is still passing around an id only over the wire. But we create
an object for plug-ins to work on.
This is quite a huge API break, but is probably the best bet for the
future quality. It will make nicer API instrospection (and nicer API in
binding), will fix the issues with pspec on GimpImageID in Python
bindings (which makes the current Python API unusable as soon as we need
to work on images, which is most of our plug-ins!), etc.
Also it will allow to use signals on images, which will be a great asset
when we will finally have bi-directionnal communications (i.e. plug-ins
would be able to connect to image changes, destructions, and whatnot).
Which return proper GParamSpecs. Incuding some useless testing code in
gimp_procedural_db_proc_info(), to make sure things work, will go away
again soon.
It never belonged inside "tools". Also rename its "pdb" subdirectory
to "groups". This had to happen before 2.10 so cherry-picking between
branches doesn't become a nightmare in the future.