Asset Catalogs: support reloading without losing local changes

Keep track of unsaved asset catalog changes, in a more granular way than
just one boolean per asset library. Individual catalogs can now be
marked with a flag `has_unsaved_changes`. This is taken into account
when reloading data from the catalog definition file (CDF):

- New catalog in CDF: gets loaded
- Already-known catalog in CDF:
    - local unsaved changes: on-disk catalog is ignored
    - otherwise: on-disk catalog replaces in-memory one
- Already-known catalog that does not exist in CDF:
    - local unsaved changes: catalog is kept around
    - otherwise: catalog is deleted.

Because this saving-is-also-loading behaviour, the "has unsaved changes"
flags are all stored in the undo buffer; undoing after saving will not
change the CDF, but at least it'll undo the loading from disk, and it'll
re-mark any changes as "not saved".

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D12967

1 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_asset_library.hh b/source/blender/blenkernel/BKE_asset_library.hh
index 64c8afecaef..15f7991e75e 100644
--- a/source/blender/blenkernel/BKE_asset_library.hh
+++ b/source/blender/blenkernel/BKE_asset_library.hh
@@ -49,6 +49,9 @@ struct AssetLibrary {
 
   void load(StringRefNull library_root_directory);
 
+  /** Load catalogs that have changed on disk. */
+  void refresh();
+
   /**
    * Update `catalog_simple_name` by looking up the asset's catalog by its ID.
    *