bonsai - fix error removing non-linked styles

including non-ifcsurfacestyle ifcpresentationstyles

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

@@ -50,6 +50,7 @@ class StylesData:
         materials: dict[bpy.types.PropertyGroup, Union[str, None]] = {}
         for style in props.styles:
             material = tool.Ifc.get_object(ifc_file.by_id(style.ifc_definition_id))
+            # Material will be None if it's either unlinked or if it's not IfcSurfaceStyle.
             materials[style] = material.name if material is not None else None
         return materials
 

src/bonsai/bonsai/core/style.py

@@ -70,7 +70,8 @@ def remove_style(
     style_type = style_tool.get_active_style_type()
     ifc.unlink(element=style)
     ifc.run("style.remove_style", style=style)
-    style_tool.delete_object(obj)
+    if obj:
+        style_tool.delete_object(obj)
     if reload_styles_ui and style_tool.is_editing_styles():
         style_tool.import_presentation_styles(style_type)