Plug-ins that work from different bindings probably want to use their
own list-type to specify arguments, rather than working with a more
cumbersome `GimpValueArray`.
This new API should make it less verbose. For example:
```
args = Gimp.ValueArray.new(5)
args.insert(0, GObject.Value(Gimp.RunMode, Gimp.RunMode.NONINTERACTIVE))
args.insert(1, GObject.Value(Gimp.Image, image))
args.insert(2, GObject.Value(Gimp.Drawable, mask))
args.insert(3, GObject.Value(GObject.TYPE_INT, int(time.time())))
args.insert(4, GObject.Value(GObject.TYPE_DOUBLE, turbulence))
Gimp.get_pdb().run_procedure('plug-in-plasma', args)
```
becomes
```
Gimp.get_pdb().run_procedure('plug-in-plasma', [
GObject.Value(Gimp.RunMode, Gimp.RunMode.NONINTERACTIVE),
GObject.Value(Gimp.Image, image),
GObject.Value(Gimp.Drawable, mask),
GObject.Value(GObject.TYPE_INT, int(time.time())),
GObject.Value(GObject.TYPE_DOUBLE, turbulence),
])
```
Break reference cycles between the objects and the procedures they
keep by moving procedure destruction to dispose() and calling
g_object_run_dispose() before unrefing PLUG_IN and PDB in gimp.c.
Also some formatting and "Since: 3.0" annotation .
which frees exactly what _gimp_value_array_to_gp_params() has
allocated, honors its "full_copy" parameter, and plugs the last
libgimp refactoring leaks I'm currently aware of.
for procedure arguments. This implies creating a new value array in
gimp_procedure_run() if the passed array is too short, instead of
just appending to the passed array, which was ugly anyway.
Especially as an example of setting a (rename-to) since variable
arguments are not introspectable, hence gimp_pdb_run_procedure() won't
be available for non-C plug-ins.
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.
