edit style for rep item - fallback in case user has no styles #6764

Or if style was removed in the process of editing. And it seems now UI will never appear broken that way.

Previously - https://files.catbox.moe/exhkln.png
Currently - https://files.catbox.moe/r36be8.png

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -2558,7 +2558,8 @@ class EnableEditingRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator
         ifc_file = tool.Ifc.get()
 
         # set dropdown to currently active style
-        representation_item_id = props.active_item.ifc_definition_id
+        assert (active_item := props.active_item)
+        representation_item_id = active_item.ifc_definition_id
         representation_item = ifc_file.by_id(representation_item_id)
         style = tool.Style.get_representation_item_style(representation_item)
         if style:
@@ -2577,8 +2578,14 @@ class EditRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator):
         props.is_editing_item_style = False
         ifc_file = tool.Ifc.get()
 
-        surface_style = ifc_file.by_id(int(props.representation_item_style))
-        representation_item_id = props.active_item.ifc_definition_id
+        surface_style_id = tool.Blender.get_enum_safe(props, "representation_item_style")
+        if surface_style_id in (None, "-"):
+            surface_style = None
+        else:
+            surface_style = ifc_file.by_id(int(props.representation_item_style))
+
+        assert (active_item := props.active_item)
+        representation_item_id = active_item.ifc_definition_id
         representation_item = ifc_file.by_id(representation_item_id)
 
         tool.Style.assign_style_to_representation_item(representation_item, surface_style)

src/bonsai/bonsai/bim/module/material/data.py

@@ -101,7 +101,9 @@ class MaterialsData:
             for s in tool.Ifc.get().by_type("IfcPresentationStyle")
             if (style_name := s.Name) is not None
         ]
-        return natsorted(results, key=lambda i: i[1])
+        results = natsorted(results, key=lambda i: i[1])
+        results.insert(0, ("-", "No Surface Style", ""))
+        return results
 
     @classmethod
     def material_styles_data(cls) -> dict[int, list[dict[str, Any]]]: