The new function gimp_procedure_set_sensitivity_mask() allows plug-ins
to tell when a procedure should be marked as sensitive or not.
gimp_procedure_get_sensitivity_mask() retrieves this information.
Currently plug-ins are automatically marked as sensitive when an image
is present and a single drawable is selected. Nowadays, we can have
multiple selected layers so we should allow plug-ins to tell us if they
support working on multiple drawables. Actually we could even imagine
new plug-ins which would be made to work only on multiple drawables.
Oppositely, there are a lot of plug-ins which don't care at all if any
drawable is selected at all (so we should allow no drawable selected).
Finally why not even imagine plug-ins which don't care if no image is
shown? E.g. plug-ins to create new images or whatnot. This new API
allows our core to know all this and show procedure sensitivity
accordingly. By default, when the function is not called, the 1 image
with 1 drawable selected case is the default, allowing existing plug-ins
easier update.
Note: this only handles the sensitivity part right now. A plug-in which
would advertize working on several layer would still not work, because
the core won't allow sending several layers. It's coming in further
commits.
and call it gimp_pdb_set_proc_icon(). Change icon registration code in
libgimp/ and app/ so it's now possible to register icons for temporary
procedures.
By default the new API will be used. But if we build with
GIMP_DEPRECATED_REPLACE_NEW_API macro, then the same function names will
call the old API with ids.
This way, we don't have to update all our plug-ins at once (which I
tried and is very tedious work).
Note that bindings won't have access to the deprecated API at all.