Add option to link assets on drag & drop

Note: Linking in this case as in link vs. append. Easily confused with linking
a data-block to multiple usages (e.g. single material used by multiple
objects).

Adds a drop-down to the Asset Browser header to choose between Link and Append.
This is probably gonna be a temporary place, T54642 shows where this could be
placed eventually.

Linking support is crucial for usage of the asset browser in production
environments. It just wasn't enabled yet because a) the asset project currently
focuses on single user, not production assets, and b) because there were many
unkowns still for the workflow that have big impact on production use as well.
With the recently held asset workshop I'm more confident with enabling linking,
as design ideas relevant to production use were confirmed.

Differential Revision: https://developer.blender.org/D11536

Reviewed by: Bastien Montagne

1 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index bb356e4b532..3cd576a9641 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -6569,6 +6569,16 @@ static void rna_def_fileselect_asset_params(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
+  static const EnumPropertyItem asset_import_type_items[] = {
+      {FILE_ASSET_IMPORT_LINK, "LINK", 0, "Link", "Import the assets as linked data-block"},
+      {FILE_ASSET_IMPORT_APPEND,
+       "APPEND",
+       0,
+       "Append",
+       "Import the assets as copied data-block, with no link to the original asset data-block"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
   srna = RNA_def_struct(brna, "FileAssetSelectParams", "FileSelectParams");
   RNA_def_struct_ui_text(
       srna, "Asset Select Parameters", "Settings for the file selection in Asset Browser mode");
@@ -6590,6 +6600,13 @@ static void rna_def_fileselect_asset_params(BlenderRNA *brna)
                               NULL);
   RNA_def_property_ui_text(prop, "Asset Category", "Determine which kind of assets to display");
   RNA_def_property_update(prop, NC_SPACE | ND_SPACE_FILE_LIST, NULL);
+
+  prop = RNA_def_property(srna, "import_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, asset_import_type_items);
+  RNA_def_property_ui_text(prop, "Import Type", "Determine how the asset will be imported");
+  /* Asset drag info saved by buttons stores the import type, so the space must redraw when import
+   * type changes. */
+  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_FILE_LIST, NULL);
 }
 
 static void rna_def_filemenu_entry(BlenderRNA *brna)