Asset Catalogs: add catalog filter for the asset browser

Given an "active catalog" (i.e. the one selected in the UI), construct
an `AssetCatalogFilter` instance. This filter can determine whether an
asset should be shown or not. It returns `true` when The asset's catalog
ID is:

- the active catalog,
- an alias of the active catalog (so different UUID that maps to the
  same path),
- a sub-catalog of the active catalog.

Not yet hooked up to the UI.

1 files changed, 26 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_asset_catalog.hh b/source/blender/blenkernel/BKE_asset_catalog.hh
index 052cf8e9d1e..65082f06f3a 100644
--- a/source/blender/blenkernel/BKE_asset_catalog.hh
+++ b/source/blender/blenkernel/BKE_asset_catalog.hh
@@ -26,6 +26,7 @@
 
 #include "BLI_function_ref.hh"
 #include "BLI_map.hh"
+#include "BLI_set.hh"
 #include "BLI_string_ref.hh"
 #include "BLI_uuid.h"
 #include "BLI_vector.hh"
@@ -48,6 +49,7 @@ using CatalogFilePath = std::string;
 class AssetCatalog;
 class AssetCatalogDefinitionFile;
 class AssetCatalogTree;
+class AssetCatalogFilter;
 
 /* Manages the asset catalogs of a single asset library (i.e. of catalogs defined in a single
  * directory hierarchy). */
@@ -100,6 +102,14 @@ class AssetCatalogService {
    * efficient call as it's just a linear search over the catalogs. */
   AssetCatalog *find_catalog_by_path(const AssetCatalogPath &path) const;
 
+  /**
+   * Create a filter object that can be used to determine whether an asset belongs to the given
+   * catalog, or any of the catalogs in the sub-tree rooted at the given catalog.
+   *
+   * \see #AssetCatalogFilter
+   */
+  AssetCatalogFilter create_catalog_filter(CatalogID active_catalog_id) const;
+
   /** Create a catalog with some sensible auto-generated catalog ID.
    * The catalog will be saved to the default catalog file.*/
   AssetCatalog *create_catalog(const AssetCatalogPath &catalog_path);
@@ -331,4 +341,20 @@ struct AssetCatalogPathCmp {
  * Being a set, duplicates are removed. The catalog's simple name is ignored in this. */
 using AssetCatalogOrderedSet = std::set<const AssetCatalog *, AssetCatalogPathCmp>;
 
+/**
+ * Filter that can determine whether an asset should be visible or not, based on its catalog ID.
+ *
+ * \see AssetCatalogService::create_filter()
+ */
+class AssetCatalogFilter {
+ public:
+  bool contains(CatalogID asset_catalog_id) const;
+
+ protected:
+  friend AssetCatalogService;
+  const Set<CatalogID> matching_catalog_ids;
+
+  explicit AssetCatalogFilter(Set<CatalogID> &&matching_catalog_ids);
+};
+
 }  // namespace blender::bke