Return flags based on what metadata is actually present in the image.
Returning of a suggested value for GIMP_METADATA_SAVE_THUMBNAIL needs
support from gimp_image_metadata_load_prepare() and is still missing.
Port all plug-ins to use the new API, the suggested values are however
overridden by parasites and whatever special code was devised for the
individual plug-ins. This needs to be fixed.
So the plug-in has the chance to decide whether it wants to trust the
metadata information (e.g. resolution). Also reorder parameters in
gimp_image_metadata_save_finish(). Change all plug-ins accordingly.
Based on original patches from Hartmut Kuhse and modified
by Michael Natterer. Changes include:
- remove libexif dependency and add a hard dependency on gexiv2
- typedef GExiv2Metadata to GimpMetadata to avoid having to
include gexiv2 globally
- add basic GimpMetadata handling functions to libgimpbase
- add image and image file specific metadata functions to libgimp,
including the exif orientation image rotate dialog
- port plug-ins to use the new APIs
- port file-tiff-save's UI to GtkBuilder
- add new plug-in "metadata" to view the image's metadata
- keep metadata around as GimpImage member in the core
- update the image's metadata on image size, resolution and precision
changes
- obsolete the old metadata parasites
- migrate the old parasites to new GimpMetadata object on XCF load
