This new function is an alternative to existing
gimp_image_metadata_save_finish, when you want to save metadata
yourself and you need only filtering processing.
It returns filtered metadata allowing the caller
to save the finalized metadata via other means
(via native format’s library for example)
This API can be used to support metadata saving of image formats
not directly supported by gexiv2/exiv2.
Orientation is now handled by core code, just next to profile conversion
handling.
One of the first consequence is that we don't need to have a non-GUI
version gimp_image_metadata_load_finish_batch() in libgimp, next to a
GUI version of the gimp_image_metadata_load_finish() function in
libgimpui. This makes for simpler API.
Also a plug-in which wishes to get access to the rotation dialog
provided by GIMP without loading ligimpui/GTK+ (for whatever reason)
will still have the feature.
The main advantage is that the "Don't ask me again" feature is now
handled by a settings in `Preferences > Image Import & Export` as the
"Metadata rotation policy". Until now it was saved as a global parasite,
which made it virtually non-editable once you checked it once (no easy
way to edit parasites except by scripts). So say you refused the
rotation once while checking "Don't ask again", and GIMP will forever
discard the rotation metadata without giving you a sane way to change
your mind. Of course, I could have passed the settings to plug-ins
through the PDB, but I find it a lot better to simply handle such
settings core-side.
The dialog code is basically the same as an app/dialogs/ as it was in
libgimp, with the minor improvement that it now takes the scale ratio
into account (basically the maximum thumbnail size will be bigger on
higher density displays).
Only downside of the move to the core is that this rotation dialog is
raised only when you open an image from the core, not as a PDB call. So
a plug-in which makes say a "file-jpeg-load" PDB call, even in
INTERACTIVE run mode, won't have rotation processed. Note that this was
already the same for embedded color profile conversion. This can be
wanted or not. Anyway some additional libgimp calls might be of interest
to explicitly call the core dialogs.
gimpimagemetadata.[ch] was built into libgimpui because GTK+ was used
for dialog query for rotation metadata. gimpimagemetadata-save.c only
was built into libgimp, which made no sense as the declaration for its
public function was inside gimpimagemetadata.h!
That was a weird situation and somehow only made visible in the build
system because GIR build was complaining about missing annotations to
gimp_image_metadata_save_prepare() (the annotation was actually present
but in the implementation which was not in the same library as the
header, how weird!):
> Warning: GimpUi: gimp_image_metadata_save_prepare: return value: Missing (transfer) annotation
Moreover it means that only plug-ins linking libgimpui had access to the
gimp_image_metadata*() API, which is obviously not cool (that should be
a core API).
Instead I moved everything into libgimp and replaced
gimp_image_metadata_load_finish() with
gimp_image_metadata_load_finish_batch(), which is essentially the same
function except that it's not interactive (it will proceed to rotate the
image without user confirmation, provided the right flag is present).
Then I add gimpimagemetadata-interactive.[ch] which contains only
gimp_image_metadata_load_finish() and is the alternative interactive
version of gimp_image_metadata_load_finish_batch(). Most plug-ins won't
even have to be changed (at least none in core GIMP) and would still
work as before, whereas now a non-interactive version exists, which
doesn't mandate to link GTK+.
Same as previous commit: by default the new API will be used. But if a
plug-in builds with GIMP_DEPRECATED_REPLACE_NEW_API macro, then the same
function names will call the old API with ids.
Daniel Novomeský