This goes with our planned change of not making GimpProcedure arguments order
relevant anymore regarding the PDB API. In particular, it means we don't want to
use GimpValueArray for various procedure arguments API, but directly
GimpProcedureConfig objects.
This change will allow to add or reorder arguments in the future, so that we
won't have to create new PDB procedures when adding new arguments, while still
keeping PDB API stability.
This is just a method to simplify transforming a GimpChoice argument into an
enum value, which is easier to deal with, in C. It also allows to benefit from
switch() warnings or the like to make sure no cases are missing.
Add gimp_procedure_config_begin_export() and end_export() which
are wrappers around begin_run() and end_run() and additionally
pretty much completely manage GimpMetadata handling.
A GimpProcedureConfig can provide boolean properties "save-exif",
"save-xmp" etc. in order to have them automatically managed by
begin_export() and end_export(). This also restores the feature of
overriding the procedure's saved default values with export
preferences, but not the values from the last export, like it
used to be in 2.10.
Move gimp_image_metadata_save_prepare() and save_finish() (which are
now completely handled by GimpProcedureConfig) from libgimpui to
libgimp, but keep their declarations in the libgimpui header. Not
perfect, but not finished either.
Also fix gimp_image_metadata_save_prepare() to set the affected
GimpMetadataSaveFlags to 0 when the image has no metadata at all.
and remember them internally between begin_run() and end_run().
Simplifies plug-in code even more.
Move the begin_run() before gimp_export_image() block in all export
plug-ins.
When non-NULL, the code tries to load/save image-specific last used
values from/to the image using a parasite. This is meant to be used by
file export plug-ins.
Alx Sa