Core procedures are all the procedures created for libgimp basically. In
opposition, procedures created by plug-ins are not core procedures.
GimpProcedure class in libgimp now has a gimp_procedure_is_core() which
will tell you if a procedure is core or not.
Private procedures already existed, except that they were only marked as
"private" in libgimp (e.g. _gimp_font_get_lookup_name()) starting with
an underscore and marked as G_GNUC_INTERNAL. Now we also store this
information in the procedure object itself for reuse.
Though I am not fond of these macros for our core code (it makes the
code more cumbersome especially for using private data in derivable
types), this definitely makes sense for public API, since it would allow
easier modifications with less chances of messing API/ABI stability.
Same for gimp_procedure_add_aux_argument() and gimp_procedure_add_return_value().
We now have specific public functions for every supported type and it's
in fact much better to use them. The generic functions gave the feeling
that we could use any GParamSpec as procedure argument, whereas we in
fact depend on what the PDB support, and only these subtypes.
GLib has a specific type of NULL-terminated string arrays:
`G_TYPE_STRV`, which is the `GType` of `char**` aka `GStrv`.
By using this type, we can avoid having a `GimpStringArray` which is a
bit cumbersome to use for both the C API, as well as bindings. By using
`GStrv`, we allow other languages to pass on string lists as they are
used to, while the bindings will make sure to do the right thing.
In the end, it makes the API a little bit simpler for everyone, and
reduces confusion for people who are used to working with string arrays
in other C/GLib based code (and not having 2 different types to denote
the same thing).
Related: https://gitlab.gnome.org/GNOME/gimp/-/issues/5919
The idea is that we already have a GimpProcedure object in libgimp
which has name, help, blurb, arguments, return values and everything,
so we really don't need a parallel API to query PDB procedures for
their properties.
- make run() a virtual function of GimpProcedure
- move GIMP_PDB_ERROR to GimpPDB
- GimpPDBProcedure is a trivial subblass which populates
GimpProcedure's members by querying the PDB.
- make "plug-in", "procedure-type" and "name" construct-only
properties of GimpProcedure.
This is all work in progress.
