Assets: Additions/fixes to the catalog system in preparation for the UI

* Fixes missing update of the catalog tree when adding catalogs.
* Adds iterators for the catalogs, needed for UI code.
* Store catalog ID in the catalog tree items, needed for UI code.
* Other smaller API additions for the UI.
* Improve comments and smaller cleanups.

New functions are covered with unit tests.

Differential Revision: https://developer.blender.org/D12618

Reviewed by: Sybren Stüvel

1 files changed, 38 insertions, 8 deletions

diff --git a/source/blender/blenkernel/BKE_asset_catalog.hh b/source/blender/blenkernel/BKE_asset_catalog.hh
index cf9d581b148..07373caf701 100644
--- a/source/blender/blenkernel/BKE_asset_catalog.hh
+++ b/source/blender/blenkernel/BKE_asset_catalog.hh
@@ -86,6 +86,10 @@ class AssetCatalogService {
   /** Return catalog with the given ID. Return nullptr if not found. */
   AssetCatalog *find_catalog(CatalogID catalog_id);
 
+  /** Return first catalog with the given path. Return nullptr if not found. This is not an
+   * efficient call as it's just a linear search over the catalogs. */
+  AssetCatalog *find_catalog_by_path(const CatalogPath &path) 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 CatalogPath &catalog_path);
@@ -124,48 +128,74 @@ class AssetCatalogService {
   void rebuild_tree();
 };
 
+/**
+ * Representation of a catalog path in the #AssetCatalogTree.
+ */
 class AssetCatalogTreeItem {
-  friend class AssetCatalogService;
+  friend class AssetCatalogTree;
 
  public:
+  /** Container for child items. Uses a #std::map to keep items ordered by their name (i.e. their
+   * last catalog component). */
   using ChildMap = std::map<std::string, AssetCatalogTreeItem>;
-  using ItemIterFn = FunctionRef<void(const AssetCatalogTreeItem &)>;
+  using ItemIterFn = FunctionRef<void(AssetCatalogTreeItem &)>;
 
-  AssetCatalogTreeItem(StringRef name, const AssetCatalogTreeItem *parent = nullptr);
+  AssetCatalogTreeItem(StringRef name,
+                       CatalogID catalog_id,
+                       const AssetCatalogTreeItem *parent = nullptr);
 
+  CatalogID get_catalog_id() const;
   StringRef get_name() const;
   /** Return the full catalog path, defined as the name of this catalog prefixed by the full
    * catalog path of its parent and a separator. */
   CatalogPath catalog_path() const;
   int count_parents() const;
+  bool has_children() const;
 
-  static void foreach_item_recursive(const ChildMap &children_, const ItemIterFn callback);
+  /** Iterate over children calling \a callback for each of them, but do not recurse into their
+   * children. */
+  void foreach_child(const ItemIterFn callback);
 
  protected:
   /** Child tree items, ordered by their names. */
   ChildMap children_;
   /** The user visible name of this component. */
   CatalogPathComponent name_;
+  CatalogID catalog_id_;
 
   /** Pointer back to the parent item. Used to reconstruct the hierarchy from an item (e.g. to
    * build a path). */
   const AssetCatalogTreeItem *parent_ = nullptr;
+
+ private:
+  static void foreach_item_recursive(ChildMap &children_, ItemIterFn callback);
 };
 
 /**
  * A representation of the catalog paths as tree structure. Each component of the catalog tree is
- * represented by a #AssetCatalogTreeItem.
+ * represented by an #AssetCatalogTreeItem. The last path component of an item is used as its name,
+ * which may also be shown to the user.
+ * An item can not have multiple children with the same name. That means the name uniquely
+ * identifies an item within its parent.
+ *
  * There is no single root tree element, the #AssetCatalogTree instance itself represents the root.
  */
 class AssetCatalogTree {
-  friend class AssetCatalogService;
+  using ChildMap = AssetCatalogTreeItem::ChildMap;
+  using ItemIterFn = AssetCatalogTreeItem::ItemIterFn;
 
  public:
-  void foreach_item(const AssetCatalogTreeItem::ItemIterFn callback) const;
+  /** Ensure an item representing \a path is in the tree, adding it if necessary. */
+  void insert_item(const AssetCatalog &catalog);
+
+  void foreach_item(const AssetCatalogTreeItem::ItemIterFn callback);
+  /** Iterate over root items calling \a callback for each of them, but do not recurse into their
+   * children. */
+  void foreach_root_item(const ItemIterFn callback);
 
  protected:
   /** Child tree items, ordered by their names. */
-  AssetCatalogTreeItem::ChildMap children_;
+  ChildMap root_items_;
 };
 
 /** Keeps track of which catalogs are defined in a certain file on disk.