Asset Browser: add operator for installing asset bundles

Add an operator "Copy to Asset Library" for installing asset bundles
into already-existing asset libraries.

The operator is shown when:
- the "Current File" library is selected,
- the blend file name matches `*_bundle.blend`, and
- the file is not already located in an asset library.

The user can select a target asset library, then gets a "Save As"
dialogue box to select where in that library the file should be saved.
This allows for renaming, saving in a subdirectory, etc.

The Asset Catalogs from the asset bundle are merged into the target
asset library.

The operator will refuse to run when external files are referenced. This
is not done in its poll function, as it's quite an extensive operator
(it loops over all ID datablocks).

Reviewed by: Severin

Differential Revision: https://developer.blender.org/D13312

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index 798f60fba3d..b780fef289a 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -1611,6 +1611,16 @@ int WM_operator_name_call(bContext *C, const char *opstring, short context, Poin
   return 0;
 }
 
+bool WM_operator_name_poll(bContext *C, const char *opstring)
+{
+  wmOperatorType *ot = WM_operatortype_find(opstring, 0);
+  if (!ot) {
+    return false;
+  }
+
+  return WM_operator_poll(C, ot);
+}
+
 int WM_operator_name_call_with_properties(struct bContext *C,
                                           const char *opstring,
                                           short context,