typing & use common tool.Ifc.Operator class

Lazy imported some modules to prevent circular imports.

src/blenderbim/blenderbim/bim/handler.py

@@ -20,6 +20,8 @@ import os
 import bpy
 import json
 import addon_utils
+import ifcopenshell.util.element
+import ifcopenshell.util.representation
 import ifcopenshell.api.owner.settings
 import blenderbim.bim
 import blenderbim.tool as tool

src/blenderbim/blenderbim/bim/import_ifc.py

@@ -36,7 +36,6 @@ import blenderbim.tool as tool
 from itertools import chain, accumulate
 from blenderbim.bim.ifc import IfcStore, IFC_CONNECTED_TYPE
 from blenderbim.tool.loader import OBJECT_DATA_TYPE
-from blenderbim.bim.module.drawing.prop import ANNOTATION_TYPES_DATA
 from typing import Dict, Union, Optional, Any
 
 
@@ -1262,9 +1261,12 @@ class IfcImporter:
             if isinstance(obj, bpy.types.Object):
                 tool.Collector.assign(obj)
 
-    def is_curve_annotation(self, element):
+    def is_curve_annotation(self, element: ifcopenshell.entity_instance) -> bool:
         object_type = element.ObjectType
-        return object_type in ANNOTATION_TYPES_DATA and ANNOTATION_TYPES_DATA[object_type][3] == "curve"
+        return (
+            object_type in tool.Drawing.ANNOTATION_TYPES_DATA
+            and tool.Drawing.ANNOTATION_TYPES_DATA[object_type][3] == "curve"
+        )
 
     def get_drawing_group(self, element):
         for rel in element.HasAssignments or []:

src/blenderbim/blenderbim/bim/module/aggregate/operator.py

@@ -26,14 +26,7 @@ import blenderbim.bim.handler
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class BIM_OT_aggregate_assign_object(bpy.types.Operator, Operator):
+class BIM_OT_aggregate_assign_object(bpy.types.Operator, tool.Ifc.Operator):
     """Create aggregation relationship between two ifc elements"""
 
     bl_idname = "bim.aggregate_assign_object"
@@ -75,7 +68,7 @@ class BIM_OT_aggregate_assign_object(bpy.types.Operator, Operator):
                 self.report({"ERROR"}, f"Cannot aggregate to {relating_obj.name} with a body representation")
 
 
-class BIM_OT_aggregate_unassign_object(bpy.types.Operator, Operator):
+class BIM_OT_aggregate_unassign_object(bpy.types.Operator, tool.Ifc.Operator):
     """Remove aggregation relationship between two ifc elements"""
 
     bl_idname = "bim.aggregate_unassign_object"
@@ -106,7 +99,7 @@ class BIM_OT_aggregate_unassign_object(bpy.types.Operator, Operator):
                     ifcopenshell.api.run("pset.remove_pset", tool.Ifc.get(), product=element, pset=pset)
 
               
-class BIM_OT_enable_editing_aggregate(bpy.types.Operator, Operator):
+class BIM_OT_enable_editing_aggregate(bpy.types.Operator, tool.Ifc.Operator):
     """Enable editing aggregation relationship"""
 
     bl_idname = "bim.enable_editing_aggregate"
@@ -117,7 +110,7 @@ class BIM_OT_enable_editing_aggregate(bpy.types.Operator, Operator):
         core.enable_editing_aggregate(tool.Aggregate, obj=context.active_object)
 
 
-class BIM_OT_disable_editing_aggregate(bpy.types.Operator, Operator):
+class BIM_OT_disable_editing_aggregate(bpy.types.Operator, tool.Ifc.Operator):
     """Disable editing aggregation relationship"""
 
     bl_idname = "bim.disable_editing_aggregate"
@@ -268,7 +261,7 @@ class BIM_OT_select_aggregate(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class BIM_OT_add_part_to_object(bpy.types.Operator, Operator):
+class BIM_OT_add_part_to_object(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_part_to_object"
     bl_label = "Add Part to Object"
     bl_options = {"REGISTER", "UNDO"}
@@ -293,7 +286,7 @@ class BIM_OT_add_part_to_object(bpy.types.Operator, Operator):
         blenderbim.core.spatial.import_spatial_decomposition(tool.Spatial)
 
 
-class BIM_OT_break_link_to_other_aggregates(bpy.types.Operator, Operator):
+class BIM_OT_break_link_to_other_aggregates(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.break_link_to_other_aggregates"
     bl_label = "Break link to other aggregates"
     bl_options = {"REGISTER", "UNDO"}
@@ -324,7 +317,7 @@ class BIM_OT_break_link_to_other_aggregates(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class BIM_OT_select_linked_aggregates(bpy.types.Operator, Operator):
+class BIM_OT_select_linked_aggregates(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.select_linked_aggregates"
     bl_label = "Select linked aggregates"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/attribute/operator.py

@@ -28,13 +28,6 @@ import blenderbim.core.attribute as core
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class EnableEditingAttributes(bpy.types.Operator):
     bl_idname = "bim.enable_editing_attributes"
     bl_label = "Enable Editing Attributes"
@@ -89,7 +82,7 @@ class DisableEditingAttributes(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class EditAttributes(bpy.types.Operator, Operator):
+class EditAttributes(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_attributes"
     bl_label = "Edit Attributes"
     bl_options = {"REGISTER", "UNDO"}
@@ -118,7 +111,7 @@ class EditAttributes(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class GenerateGlobalId(bpy.types.Operator, Operator):
+class GenerateGlobalId(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.generate_global_id"
     bl_label = "Regenerate GlobalId"
     bl_description = "Regenerate GlobalId\n\nSHIFT+CLICK to regenerate GlobalIds for all selected objects"
@@ -161,7 +154,7 @@ class GenerateGlobalId(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class CopyAttributeToSelection(bpy.types.Operator, Operator):
+class CopyAttributeToSelection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.copy_attribute_to_selection"
     bl_label = "Copy Attribute To Selection"
     name: bpy.props.StringProperty()

src/blenderbim/blenderbim/bim/module/brick/operator.py

@@ -26,14 +26,7 @@ from blenderbim.bim.ifc import IfcStore
 from blenderbim.tool.brick import BrickStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class LoadBrickProject(bpy.types.Operator, Operator):
+class LoadBrickProject(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_brick_project"
     bl_label = "Load Brickschema Project"
     bl_options = {"REGISTER", "UNDO"}
@@ -53,7 +46,7 @@ class LoadBrickProject(bpy.types.Operator, Operator):
         return {"RUNNING_MODAL"}
 
 
-class ViewBrickClass(bpy.types.Operator, Operator):
+class ViewBrickClass(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.view_brick_class"
     bl_label = "View Brick Class"
     bl_options = {"REGISTER", "UNDO"}
@@ -65,7 +58,7 @@ class ViewBrickClass(bpy.types.Operator, Operator):
         core.view_brick_class(tool.Brick, brick_class=self.brick_class, split_screen=self.split_screen)
 
 
-class ViewBrickItem(bpy.types.Operator, Operator):
+class ViewBrickItem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.view_brick_item"
     bl_label = "View Brick Item"
     bl_options = {"REGISTER", "UNDO"}
@@ -80,7 +73,7 @@ class ViewBrickItem(bpy.types.Operator, Operator):
             self.report({'ERROR'}, f'Could not find {self.item}')
 
 
-class RewindBrickClass(bpy.types.Operator, Operator):
+class RewindBrickClass(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.rewind_brick_class"
     bl_label = "Rewind Brick Class"
     bl_options = {"REGISTER", "UNDO"}
@@ -91,7 +84,7 @@ class RewindBrickClass(bpy.types.Operator, Operator):
         core.rewind_brick_class(tool.Brick, split_screen=self.split_screen)
 
 
-class CloseBrickProject(bpy.types.Operator, Operator):
+class CloseBrickProject(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.close_brick_project"
     bl_label = "Close Brick Project"
     bl_options = {"REGISTER", "UNDO"}
@@ -101,7 +94,7 @@ class CloseBrickProject(bpy.types.Operator, Operator):
         core.close_brick_project(tool.Brick)
 
 
-class ConvertBrickProject(bpy.types.Operator, Operator):
+class ConvertBrickProject(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.convert_brick_project"
     bl_label = "Convert Brick Project"
     bl_options = {"REGISTER", "UNDO"}
@@ -111,7 +104,7 @@ class ConvertBrickProject(bpy.types.Operator, Operator):
         core.convert_brick_project(tool.Ifc, tool.Brick)
 
 
-class AssignBrickReference(bpy.types.Operator, Operator):
+class AssignBrickReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_brick_reference"
     bl_label = "Assign Brick Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -136,7 +129,7 @@ class AssignBrickReference(bpy.types.Operator, Operator):
         )
 
 
-class AddBrick(bpy.types.Operator, Operator):
+class AddBrick(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_brick"
     bl_label = "Add Brick"
     bl_options = {"REGISTER", "UNDO"}
@@ -155,7 +148,7 @@ class AddBrick(bpy.types.Operator, Operator):
         )
 
 
-class AddBrickRelation(bpy.types.Operator, Operator):
+class AddBrickRelation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_brick_relation"
     bl_label = "Add Brick Relation"
     bl_options = {"REGISTER", "UNDO"}
@@ -178,7 +171,7 @@ class AddBrickRelation(bpy.types.Operator, Operator):
         )
 
 
-class ConvertIfcToBrick(bpy.types.Operator, Operator):
+class ConvertIfcToBrick(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.convert_ifc_to_brick"
     bl_label = "Convert IFC To Brick"
     bl_options = {"REGISTER", "UNDO"}
@@ -225,7 +218,7 @@ class NewBrickFile(bpy.types.Operator):
         BrickStore.graph = data["graph"]
 
 
-class RefreshBrickViewer(bpy.types.Operator, Operator):
+class RefreshBrickViewer(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.refresh_brick_viewer"
     bl_label = "Refresh Brick Viewer"
     bl_options = {"REGISTER", "UNDO"}
@@ -235,7 +228,7 @@ class RefreshBrickViewer(bpy.types.Operator, Operator):
         core.refresh_brick_viewer(tool.Brick)
 
 
-class RemoveBrick(bpy.types.Operator, Operator):
+class RemoveBrick(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_brick"
     bl_label = "Remove Brick"
     bl_options = {"REGISTER", "UNDO"}
@@ -279,7 +272,7 @@ class SerializeBrick(bpy.types.Operator):
         return "Save the Brick project"
 
 
-class AddBrickNamespace(bpy.types.Operator, Operator):
+class AddBrickNamespace(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_brick_namespace"
     bl_label = "Add Brick Namespace"
     bl_description = "Bind a new namespace to the Brick project"
@@ -291,7 +284,7 @@ class AddBrickNamespace(bpy.types.Operator, Operator):
         core.add_brick_namespace(tool.Brick, alias=alias, uri=uri)
 
 
-class RemoveBrickRelation(bpy.types.Operator, Operator):
+class RemoveBrickRelation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_brick_relation"
     bl_label = "Remove Relation"
     bl_options = {"REGISTER", "UNDO"}
@@ -302,4 +295,4 @@ class RemoveBrickRelation(bpy.types.Operator, Operator):
     def _execute(self, context):
         props = context.scene.BIMBrickProperties
         brick = props.bricks[props.active_brick_index]
-        core.remove_brick_relation(tool.Brick, brick_uri=brick.uri, predicate=self.predicate, object=self.object)
+        core.remove_brick_relation(tool.Brick, brick_uri=brick.uri, predicate=self.predicate, object=self.object)

src/blenderbim/blenderbim/bim/module/context/operator.py

@@ -24,14 +24,7 @@ import blenderbim.bim.handler
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class AddContext(bpy.types.Operator, Operator):
+class AddContext(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_context"
     bl_label = "Add Subcontext"
     bl_options = {"REGISTER", "UNDO"}
@@ -50,7 +43,7 @@ class AddContext(bpy.types.Operator, Operator):
         )
 
 
-class RemoveContext(bpy.types.Operator, Operator):
+class RemoveContext(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_context"
     bl_label = "Remove Context"
     bl_description = (
@@ -64,7 +57,7 @@ class RemoveContext(bpy.types.Operator, Operator):
         core.remove_context(tool.Ifc, context=tool.Ifc.get().by_id(self.context))
 
 
-class EnableEditingContext(bpy.types.Operator, Operator):
+class EnableEditingContext(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_context"
     bl_label = "Enable Editing Context"
     bl_options = {"REGISTER", "UNDO"}
@@ -74,7 +67,7 @@ class EnableEditingContext(bpy.types.Operator, Operator):
         core.enable_editing_context(tool.Context, context=tool.Ifc.get().by_id(self.context))
 
 
-class DisableEditingContext(bpy.types.Operator, Operator):
+class DisableEditingContext(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_context"
     bl_label = "Disable Editing Context"
     bl_options = {"REGISTER", "UNDO"}
@@ -83,7 +76,7 @@ class DisableEditingContext(bpy.types.Operator, Operator):
         core.disable_editing_context(tool.Context)
 
 
-class EditContext(bpy.types.Operator, Operator):
+class EditContext(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_context"
     bl_label = "Edit Context"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/covering/workspace.py

@@ -28,14 +28,6 @@ from blenderbim.bim.ifc import IfcStore
 import blenderbim.bim.handler
 
 
-# declaring it here to avoid circular import problems
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class CoveringTool(WorkSpaceTool):
     bl_space_type = "VIEW_3D"
     bl_context_mode = "OBJECT"
@@ -153,7 +145,7 @@ class CoveringToolUI:
                     op.ifc_class = cls.props.ifc_class
 
 
-class Hotkey(bpy.types.Operator, Operator):
+class Hotkey(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.covering_hotkey"
     bl_label = "Hotkey"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/drawing/operator.py

@@ -73,19 +73,12 @@ class profile:
         print(self.task, timer() - self.start)
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class LineworkContexts(NamedTuple):
     body: List[List[int]]
     annotation: List[List[int]]
 
 
-class AddAnnotationType(bpy.types.Operator, Operator):
+class AddAnnotationType(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_annotation_type"
     bl_label = "Add Annotation Type"
     bl_options = {"REGISTER", "UNDO"}
@@ -116,7 +109,7 @@ class AddAnnotationType(bpy.types.Operator, Operator):
             bpy.ops.bim.add_reference_image("INVOKE_DEFAULT", use_existing_object_by_name=obj.name)
 
 
-class EnableAddAnnotationType(bpy.types.Operator, Operator):
+class EnableAddAnnotationType(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_add_annotation_type"
     bl_label = "Enable Add Annotation Type"
     bl_options = {"REGISTER", "UNDO"}
@@ -125,7 +118,7 @@ class EnableAddAnnotationType(bpy.types.Operator, Operator):
         bpy.context.scene.BIMAnnotationProperties.is_adding_type = True
 
 
-class DisableAddAnnotationType(bpy.types.Operator, Operator):
+class DisableAddAnnotationType(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_add_annotation_type"
     bl_label = "Disable Add Annotation Type"
     bl_options = {"REGISTER", "UNDO"}
@@ -134,7 +127,7 @@ class DisableAddAnnotationType(bpy.types.Operator, Operator):
         bpy.context.scene.BIMAnnotationProperties.is_adding_type = False
 
 
-class AddDrawing(bpy.types.Operator, Operator):
+class AddDrawing(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_drawing"
     bl_label = "Add Drawing"
     bl_options = {"REGISTER", "UNDO"}
@@ -158,7 +151,7 @@ class AddDrawing(bpy.types.Operator, Operator):
             pass
 
 
-class DuplicateDrawing(bpy.types.Operator, Operator):
+class DuplicateDrawing(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.duplicate_drawing"
     bl_label = "Duplicate Drawing"
     bl_options = {"REGISTER", "UNDO"}
@@ -1185,7 +1178,7 @@ class CreateDrawing(bpy.types.Operator):
         return drawing_path
 
 
-class AddAnnotation(bpy.types.Operator, Operator):
+class AddAnnotation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_annotation"
     bl_label = "Add Annotation"
     bl_options = {"REGISTER", "UNDO"}
@@ -1212,7 +1205,7 @@ class AddAnnotation(bpy.types.Operator, Operator):
             self.report({"WARNING"}, r)
 
 
-class AddSheet(bpy.types.Operator, Operator):
+class AddSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_sheet"
     bl_label = "Add Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -1221,7 +1214,7 @@ class AddSheet(bpy.types.Operator, Operator):
         core.add_sheet(tool.Ifc, tool.Drawing, titleblock=context.scene.DocProperties.titleblock)
 
 
-class OpenSheet(bpy.types.Operator, Operator):
+class OpenSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.open_sheet"
     bl_label = "Open Sheet Layout"
     bl_options = {"REGISTER", "UNDO"}
@@ -1234,7 +1227,7 @@ class OpenSheet(bpy.types.Operator, Operator):
         core.open_sheet(tool.Drawing, sheet=sheet)
 
 
-class AddDrawingToSheet(bpy.types.Operator, Operator):
+class AddDrawingToSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_drawing_to_sheet"
     bl_label = "Add Drawing To Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -1286,7 +1279,7 @@ class AddDrawingToSheet(bpy.types.Operator, Operator):
         tool.Drawing.import_sheets()
 
 
-class RemoveDrawingFromSheet(bpy.types.Operator, Operator):
+class RemoveDrawingFromSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_drawing_from_sheet"
     bl_label = "Remove Drawing From Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -1305,7 +1298,7 @@ class RemoveDrawingFromSheet(bpy.types.Operator, Operator):
         tool.Drawing.import_sheets()
 
 
-class CreateSheets(bpy.types.Operator, Operator):
+class CreateSheets(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.create_sheets"
     bl_label = "Create Sheets"
     bl_description = "Build a sheet from the sheet layout"
@@ -1598,7 +1591,7 @@ class ResizeText(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class RemoveDrawing(bpy.types.Operator, Operator):
+class RemoveDrawing(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_drawing"
     bl_label = "Remove Drawing"
     bl_options = {"REGISTER", "UNDO"}
@@ -1701,7 +1694,7 @@ class ReloadDrawingStyles(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class AddDrawingStyle(bpy.types.Operator, Operator):
+class AddDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_drawing_style"
     bl_label = "Add Drawing Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1715,7 +1708,7 @@ class AddDrawingStyle(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class RemoveDrawingStyle(bpy.types.Operator, Operator):
+class RemoveDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_drawing_style"
     bl_label = "Remove Drawing Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1728,7 +1721,7 @@ class RemoveDrawingStyle(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class SaveDrawingStyle(bpy.types.Operator, Operator):
+class SaveDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.save_drawing_style"
     bl_label = "Save Drawing Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1793,7 +1786,7 @@ class SaveDrawingStyle(bpy.types.Operator, Operator):
                 return space
 
 
-class SaveDrawingStylesData(bpy.types.Operator, Operator):
+class SaveDrawingStylesData(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.save_drawing_styles_data"
     bl_label = "Save Drawing Styles Data"
     bl_options = {"REGISTER", "UNDO"}
@@ -1846,7 +1839,7 @@ class SaveDrawingStylesData(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class ActivateDrawingStyle(bpy.types.Operator, Operator):
+class ActivateDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.activate_drawing_style"
     bl_label = "Activate Drawing Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1935,7 +1928,7 @@ class ActivateDrawingStyle(bpy.types.Operator, Operator):
                 return space
 
 
-class RemoveSheet(bpy.types.Operator, Operator):
+class RemoveSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_sheet"
     bl_label = "Remove Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -1945,7 +1938,7 @@ class RemoveSheet(bpy.types.Operator, Operator):
         core.remove_sheet(tool.Ifc, tool.Drawing, sheet=tool.Ifc.get().by_id(self.sheet))
 
 
-class AddSchedule(bpy.types.Operator, Operator):
+class AddSchedule(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_schedule"
     bl_label = "Add Schedule"
     bl_options = {"REGISTER", "UNDO"}
@@ -1975,7 +1968,7 @@ class AddSchedule(bpy.types.Operator, Operator):
         return {"RUNNING_MODAL"}
 
 
-class RemoveSchedule(bpy.types.Operator, Operator):
+class RemoveSchedule(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_schedule"
     bl_label = "Remove Schedule"
     bl_options = {"REGISTER", "UNDO"}
@@ -1985,7 +1978,7 @@ class RemoveSchedule(bpy.types.Operator, Operator):
         core.remove_document(tool.Ifc, tool.Drawing, "SCHEDULE", document=tool.Ifc.get().by_id(self.schedule))
 
 
-class OpenSchedule(bpy.types.Operator, Operator):
+class OpenSchedule(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.open_schedule"
     bl_label = "Open Schedule"
     bl_options = {"REGISTER", "UNDO"}
@@ -1995,7 +1988,7 @@ class OpenSchedule(bpy.types.Operator, Operator):
         core.open_schedule(tool.Drawing, schedule=tool.Ifc.get().by_id(self.schedule))
 
 
-class BuildSchedule(bpy.types.Operator, Operator):
+class BuildSchedule(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.build_schedule"
     bl_label = "Build Schedule"
     schedule: bpy.props.IntProperty()
@@ -2004,7 +1997,7 @@ class BuildSchedule(bpy.types.Operator, Operator):
         core.build_schedule(tool.Drawing, schedule=tool.Ifc.get().by_id(self.schedule))
 
 
-class AddScheduleToSheet(bpy.types.Operator, Operator):
+class AddScheduleToSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_schedule_to_sheet"
     bl_label = "Add Schedule To Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -2060,7 +2053,7 @@ class AddScheduleToSheet(bpy.types.Operator, Operator):
         tool.Drawing.import_sheets()
 
 
-class AddReferenceToSheet(bpy.types.Operator, Operator):
+class AddReferenceToSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_reference_to_sheet"
     bl_label = "Add Reference To Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -2117,7 +2110,7 @@ class AddReferenceToSheet(bpy.types.Operator, Operator):
         tool.Drawing.import_sheets()
 
 
-class AddReference(bpy.types.Operator, Operator):
+class AddReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_reference"
     bl_label = "Add Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -2147,7 +2140,7 @@ class AddReference(bpy.types.Operator, Operator):
         return {"RUNNING_MODAL"}
 
 
-class RemoveReference(bpy.types.Operator, Operator):
+class RemoveReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_reference"
     bl_label = "Remove Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -2157,7 +2150,7 @@ class RemoveReference(bpy.types.Operator, Operator):
         core.remove_document(tool.Ifc, tool.Drawing, "REFERENCE", document=tool.Ifc.get().by_id(self.reference))
 
 
-class OpenReference(bpy.types.Operator, Operator):
+class OpenReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.open_reference"
     bl_label = "Open Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -2270,7 +2263,7 @@ class EditTextPopup(bpy.types.Operator):
             return {"FINISHED"}
 
 
-class EditText(bpy.types.Operator, Operator):
+class EditText(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_text"
     bl_label = "Edit Text"
     bl_options = {"REGISTER", "UNDO"}
@@ -2280,7 +2273,7 @@ class EditText(bpy.types.Operator, Operator):
         tool.Blender.update_viewport()
 
 
-class EnableEditingText(bpy.types.Operator, Operator):
+class EnableEditingText(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_text"
     bl_label = "Enable Editing Text"
     bl_options = {"REGISTER", "UNDO"}
@@ -2289,7 +2282,7 @@ class EnableEditingText(bpy.types.Operator, Operator):
         core.enable_editing_text(tool.Drawing, obj=context.active_object)
 
 
-class DisableEditingText(bpy.types.Operator, Operator):
+class DisableEditingText(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_text"
     bl_label = "Disable Editing Text"
     bl_options = {"REGISTER", "UNDO"}
@@ -2407,7 +2400,7 @@ class AssignSelectedObjectAsProduct(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class EditAssignedProduct(bpy.types.Operator, Operator):
+class EditAssignedProduct(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_assigned_product"
     bl_label = "Edit Text Product"
     bl_options = {"REGISTER", "UNDO"}
@@ -2420,7 +2413,7 @@ class EditAssignedProduct(bpy.types.Operator, Operator):
         tool.Blender.update_viewport()
 
 
-class EnableEditingAssignedProduct(bpy.types.Operator, Operator):
+class EnableEditingAssignedProduct(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_assigned_product"
     bl_label = "Enable Editing Assigned Product"
     bl_options = {"REGISTER", "UNDO"}
@@ -2429,7 +2422,7 @@ class EnableEditingAssignedProduct(bpy.types.Operator, Operator):
         core.enable_editing_assigned_product(tool.Drawing, obj=context.active_object)
 
 
-class DisableEditingAssignedProduct(bpy.types.Operator, Operator):
+class DisableEditingAssignedProduct(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_assigned_product"
     bl_label = "Disable Editing Assigned Product"
     bl_options = {"REGISTER", "UNDO"}
@@ -2438,7 +2431,7 @@ class DisableEditingAssignedProduct(bpy.types.Operator, Operator):
         core.disable_editing_assigned_product(tool.Drawing, obj=context.active_object)
 
 
-class LoadSheets(bpy.types.Operator, Operator):
+class LoadSheets(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_sheets"
     bl_label = "Load Sheets"
     bl_options = {"REGISTER", "UNDO"}
@@ -2465,7 +2458,7 @@ class LoadSheets(bpy.types.Operator, Operator):
             self.report({"ERROR"}, "Some sheets svg files are missing:\n" + "\n".join(sheets_not_found))
 
 
-class EditSheet(bpy.types.Operator, Operator):
+class EditSheet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_sheet"
     bl_label = "Edit Sheet"
     bl_options = {"REGISTER", "UNDO"}
@@ -2521,7 +2514,7 @@ class EditSheet(bpy.types.Operator, Operator):
         tool.Drawing.import_sheets()
 
 
-class DisableEditingSheets(bpy.types.Operator, Operator):
+class DisableEditingSheets(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_sheets"
     bl_label = "Disable Editing Sheets"
     bl_options = {"REGISTER", "UNDO"}
@@ -2530,7 +2523,7 @@ class DisableEditingSheets(bpy.types.Operator, Operator):
         core.disable_editing_sheets(tool.Drawing)
 
 
-class LoadSchedules(bpy.types.Operator, Operator):
+class LoadSchedules(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_schedules"
     bl_label = "Load Schedules"
     bl_options = {"REGISTER", "UNDO"}
@@ -2539,7 +2532,7 @@ class LoadSchedules(bpy.types.Operator, Operator):
         core.load_schedules(tool.Drawing)
 
 
-class DisableEditingSchedules(bpy.types.Operator, Operator):
+class DisableEditingSchedules(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_schedules"
     bl_label = "Disable Editing Schedules"
     bl_options = {"REGISTER", "UNDO"}
@@ -2548,7 +2541,7 @@ class DisableEditingSchedules(bpy.types.Operator, Operator):
         core.disable_editing_schedules(tool.Drawing)
 
 
-class LoadReferences(bpy.types.Operator, Operator):
+class LoadReferences(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_references"
     bl_label = "Load References"
     bl_options = {"REGISTER", "UNDO"}
@@ -2557,7 +2550,7 @@ class LoadReferences(bpy.types.Operator, Operator):
         core.load_references(tool.Drawing)
 
 
-class DisableEditingReferences(bpy.types.Operator, Operator):
+class DisableEditingReferences(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_references"
     bl_label = "Disable Editing References"
     bl_options = {"REGISTER", "UNDO"}
@@ -2566,7 +2559,7 @@ class DisableEditingReferences(bpy.types.Operator, Operator):
         core.disable_editing_references(tool.Drawing)
 
 
-class LoadDrawings(bpy.types.Operator, Operator):
+class LoadDrawings(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_drawings"
     bl_label = "Load Drawings"
     bl_options = {"REGISTER", "UNDO"}
@@ -2575,7 +2568,7 @@ class LoadDrawings(bpy.types.Operator, Operator):
         core.load_drawings(tool.Drawing)
 
 
-class DisableEditingDrawings(bpy.types.Operator, Operator):
+class DisableEditingDrawings(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_drawings"
     bl_label = "Disable Editing Drawings"
     bl_options = {"REGISTER", "UNDO"}
@@ -2640,7 +2633,7 @@ class ContractSheet(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class SelectAssignedProduct(bpy.types.Operator, Operator):
+class SelectAssignedProduct(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.select_assigned_product"
     bl_label = "Select Assigned Product"
     bl_options = {"REGISTER", "UNDO"}
@@ -2649,7 +2642,7 @@ class SelectAssignedProduct(bpy.types.Operator, Operator):
         core.select_assigned_product(tool.Drawing, context)
 
 
-class EnableEditingElementFilter(bpy.types.Operator, Operator):
+class EnableEditingElementFilter(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_element_filter"
     bl_label = "Enable Editing Element Filter"
     bl_options = {"REGISTER", "UNDO"}
@@ -2669,7 +2662,7 @@ class EnableEditingElementFilter(bpy.types.Operator, Operator):
                 pass
 
 
-class EditElementFilter(bpy.types.Operator, Operator):
+class EditElementFilter(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_element_filter"
     bl_label = "Edit Element Filter"
     bl_options = {"REGISTER", "UNDO"}
@@ -2690,7 +2683,7 @@ class EditElementFilter(bpy.types.Operator, Operator):
         bpy.ops.bim.activate_drawing(drawing=element.id(), camera_view_point=False)
 
 
-class AddReferenceImage(bpy.types.Operator, Operator):
+class AddReferenceImage(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_reference_image"
     bl_label = "Add Reference Image"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/drawing/prop.py

@@ -506,31 +506,9 @@ class BIMAssignedProductProperties(PropertyGroup):
     relating_product: PointerProperty(name="Relating Product", type=bpy.types.Object)
 
 
-# ObjectType: annotation_name, description, icon, data_type
-# fmt: off
-ANNOTATION_TYPES_DATA = {
-    "DIMENSION":     ("Dimension",        "Add dimensions annotation.\nMeasurement values can be hidden through ShowDescriptionOnly property\nof BBIM_Dimension property set", "FIXED_SIZE", "curve"),
-    "ANGLE":         ("Angle",            "", "DRIVER_ROTATIONAL_DIFFERENCE", "curve"),
-    "RADIUS":        ("Radius",           "", "FORWARD", "curve"),
-    "DIAMETER":      ("Diameter",         "Add diameter annotation.\nMeasurement values can be hidden through ShowDescriptionOnly property\nof BBIM_Dimension property set", "ARROW_LEFTRIGHT", "curve"),
-    "TEXT":          ("Text",             "", "SMALL_CAPS", "empty"),
-    "TEXT_LEADER":   ("Leader",           "", "TRACKING_BACKWARDS", "curve"),
-    "STAIR_ARROW":   ("Stair Arrow",      "Add stair arrow annotation.\nIf you have IfcStairFlight object selected, it will be used as a reference for the annotation", "SCREEN_BACK", "curve"),
-    "PLAN_LEVEL":    ("Level (Plan)",     "", "SORTBYEXT", "curve"),
-    "SECTION_LEVEL": ("Level (Section)",  "", "TRIA_DOWN", "curve"),
-    "BREAKLINE":     ("Breakline",        "", "FCURVE", "mesh"),
-    "SYMBOL":        ("Symbol",           "", "KEYFRAME", "empty"),
-    "MULTI_SYMBOL":  ("Multi-Symbol",     "", "OUTLINER_DATA_POINTCLOUD", "mesh"),
-    "LINEWORK":      ("Line",             "", "SNAP_MIDPOINT", "mesh"),
-    "BATTING":       ("Batting",          "Add batting annotation.\nThickness could be changed through Thickness property of BBIM_Batting property set", "FORCE_FORCE", "mesh"),
-    "REVISION_CLOUD":("Revision Cloud",   "Add revision cloud", "VOLUME_DATA", "mesh"),
-    "FILL_AREA":     ("Fill Area",        "", "NODE_TEXTURE", "mesh"),
-    "FALL":          ("Fall",             "", "SORT_ASC", "curve"),
-    "IMAGE":         ("Image",            "Add reference image attached to the drawing", "TEXTURE", "mesh"),
-}
-# fmt: on
-
-annotation_classes = [(x, *ANNOTATION_TYPES_DATA[x][:3], i) for i, x in enumerate(ANNOTATION_TYPES_DATA)]
+annotation_classes = [
+    (x, *tool.Drawing.ANNOTATION_TYPES_DATA[x][:3], i) for i, x in enumerate(tool.Drawing.ANNOTATION_TYPES_DATA)
+]
 
 
 def get_relating_type_id(self, context):

src/blenderbim/blenderbim/bim/module/drawing/ui.py

@@ -28,7 +28,6 @@ from blenderbim.bim.module.drawing.data import (
     ElementFiltersData,
     DecoratorData,
 )
-from blenderbim.bim.module.drawing.prop import ANNOTATION_TYPES_DATA
 
 
 class BIM_PT_camera(Panel):

src/blenderbim/blenderbim/bim/module/drawing/workspace.py

@@ -23,21 +23,11 @@ import blenderbim.tool as tool
 from blenderbim.bim.helper import prop_with_search
 from bpy.types import WorkSpaceTool
 
-from blenderbim.bim.module.drawing.prop import ANNOTATION_TYPES_DATA
 from blenderbim.bim.module.drawing.data import DecoratorData, AnnotationData
 from blenderbim.bim.ifc import IfcStore
 import blenderbim.bim.handler
 
 
-# TODO: Fix circular import.
-# Declaring it here to avoid circular import problems
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class LaunchAnnotationTypeManager(bpy.types.Operator):
     bl_idname = "bim.launch_annotation_type_manager"
     bl_label = "Launch Annotation Type Manager"
@@ -196,7 +186,9 @@ def create_annotation():
         create_annotation_occurrence(bpy.context)
     else:
         object_type = props.object_type
-        bpy.ops.bim.add_annotation(object_type=object_type, data_type=ANNOTATION_TYPES_DATA[object_type][-1])
+        bpy.ops.bim.add_annotation(
+            object_type=object_type, data_type=tool.Drawing.ANNOTATION_TYPES_DATA[object_type][-1]
+        )
         if props.object_type == "IMAGE":
             bpy.ops.bim.add_reference_image(
                 "INVOKE_DEFAULT", use_existing_object_by_name=bpy.context.active_object.name
@@ -266,7 +258,7 @@ class AnnotationToolUI:
             )
 
 
-class Hotkey(bpy.types.Operator, Operator):
+class Hotkey(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.annotation_hotkey"
     bl_label = "Hotkey"
     bl_options = {"REGISTER", "UNDO"}

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

@@ -43,14 +43,7 @@ from ifcopenshell.util.shape_builder import ShapeBuilder
 from typing import Any
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class EditObjectPlacement(bpy.types.Operator, Operator):
+class EditObjectPlacement(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_object_placement"
     bl_label = "Edit Object Placement"
     bl_description = (
@@ -66,7 +59,7 @@ class EditObjectPlacement(bpy.types.Operator, Operator):
             core.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj)
 
 
-class OverrideMeshSeparate(bpy.types.Operator, Operator):
+class OverrideMeshSeparate(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_mesh_separate"
     bl_label = "IFC Mesh Separate"
     bl_options = {"REGISTER", "UNDO"}
@@ -102,7 +95,7 @@ class OverrideMeshSeparate(bpy.types.Operator, Operator):
             bpy.ops.bim.update_representation(obj=new_obj.name)
 
 
-class OverrideOriginSet(bpy.types.Operator, Operator):
+class OverrideOriginSet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_origin_set"
     bl_label = "IFC Origin Set"
     bl_options = {"REGISTER", "UNDO"}
@@ -127,7 +120,7 @@ class OverrideOriginSet(bpy.types.Operator, Operator):
             bpy.ops.bim.update_representation(obj=obj.name)
 
 
-class AddRepresentation(bpy.types.Operator, Operator):
+class AddRepresentation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_representation"
     bl_label = "Add Representation"
     bl_options = {"REGISTER", "UNDO"}
@@ -253,7 +246,7 @@ class AddRepresentation(bpy.types.Operator, Operator):
             row.prop(context.scene.BIMGeometryProperties, "representation_from_object", text="")
 
 
-class SelectConnection(bpy.types.Operator, Operator):
+class SelectConnection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.select_connection"
     bl_label = "Select Connection"
     bl_options = {"REGISTER", "UNDO"}
@@ -263,7 +256,7 @@ class SelectConnection(bpy.types.Operator, Operator):
         core.select_connection(tool.Geometry, connection=tool.Ifc.get().by_id(self.connection))
 
 
-class RemoveConnection(bpy.types.Operator, Operator):
+class RemoveConnection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_connection"
     bl_label = "Remove Connection"
     bl_options = {"REGISTER", "UNDO"}
@@ -273,7 +266,7 @@ class RemoveConnection(bpy.types.Operator, Operator):
         core.remove_connection(tool.Geometry, connection=tool.Ifc.get().by_id(self.connection))
 
 
-class SwitchRepresentation(bpy.types.Operator, Operator):
+class SwitchRepresentation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.switch_representation"
     bl_label = "Switch Representation"
     bl_options = {"REGISTER", "UNDO"}
@@ -322,7 +315,7 @@ class SwitchRepresentation(bpy.types.Operator, Operator):
             )
 
 
-class RemoveRepresentation(bpy.types.Operator, Operator):
+class RemoveRepresentation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_representation"
     bl_label = "Remove Representation"
     bl_options = {"REGISTER", "UNDO"}
@@ -337,7 +330,7 @@ class RemoveRepresentation(bpy.types.Operator, Operator):
         )
 
 
-class PurgeUnusedRepresentations(bpy.types.Operator, Operator):
+class PurgeUnusedRepresentations(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.purge_unused_representations"
     bl_label = "Purge Unused Representations"
     bl_options = {"REGISTER", "UNDO"}
@@ -347,7 +340,7 @@ class PurgeUnusedRepresentations(bpy.types.Operator, Operator):
         self.report({"INFO"}, f"{purged_representations} representations were purged.")
 
 
-class UpdateRepresentation(bpy.types.Operator, Operator):
+class UpdateRepresentation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.update_representation"
     bl_label = "Update Representation"
     bl_description = (
@@ -363,8 +356,9 @@ class UpdateRepresentation(bpy.types.Operator, Operator):
             # Ensure mode is object to prevent invalid mesh data causing CTD
             bpy.ops.object.mode_set(mode="OBJECT", toggle=False)
 
-        objs = [bpy.data.objects.get(self.obj)] if self.obj else context.selected_objects
-        self.file = IfcStore.get_file()
+        obj_name: str = self.obj
+        objs = [bpy.data.objects[obj_name]] if obj_name else context.selected_objects
+        self.file = tool.Ifc.get()
 
         for obj in objs:
             # TODO: write unit tests to see how this bulk operation handles
@@ -376,7 +370,7 @@ class UpdateRepresentation(bpy.types.Operator, Operator):
             tool.Ifc.finish_edit(obj)
         return {"FINISHED"}
 
-    def update_obj_mesh_representation(self, context, obj):
+    def update_obj_mesh_representation(self, context: bpy.types.Context, obj: bpy.types.Object) -> None:
         product = self.file.by_id(obj.BIMObjectProperties.ifc_definition_id)
         material = ifcopenshell.util.element.get_material(product, should_skip_usage=True)
 
@@ -527,7 +521,7 @@ class UpdateParametricRepresentation(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class GetRepresentationIfcParameters(bpy.types.Operator, Operator):
+class GetRepresentationIfcParameters(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.get_representation_ifc_parameters"
     bl_label = "Get Representation IFC Parameters"
     bl_options = {"REGISTER", "UNDO"}
@@ -538,7 +532,7 @@ class GetRepresentationIfcParameters(bpy.types.Operator, Operator):
         self.report({"INFO"}, f"{len(parameters)} parameters found.")
 
 
-class CopyRepresentation(bpy.types.Operator, Operator):
+class CopyRepresentation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.copy_representation"
     bl_label = "Copy Representation"
     bl_options = {"REGISTER", "UNDO"}
@@ -1456,7 +1450,7 @@ class RefreshLinkedAggregate(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class OverrideJoin(bpy.types.Operator, Operator):
+class OverrideJoin(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_object_join"
     bl_label = "IFC Join"
     bl_options = {"REGISTER", "UNDO"}
@@ -1820,7 +1814,7 @@ class FlipObject(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class EnableEditingRepresentationItems(bpy.types.Operator, Operator):
+class EnableEditingRepresentationItems(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_representation_items"
     bl_label = "Enable Editing Representation Items"
     bl_options = {"REGISTER", "UNDO"}
@@ -1871,7 +1865,7 @@ class EnableEditingRepresentationItems(bpy.types.Operator, Operator):
                 props.items.move(props.items[:].index(item), i)
 
 
-class DisableEditingRepresentationItems(bpy.types.Operator, Operator):
+class DisableEditingRepresentationItems(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_representation_items"
     bl_label = "Disable Editing Representation Items"
     bl_options = {"REGISTER", "UNDO"}
@@ -1881,7 +1875,7 @@ class DisableEditingRepresentationItems(bpy.types.Operator, Operator):
         obj.BIMGeometryProperties.is_editing = False
 
 
-class RemoveRepresentationItem(bpy.types.Operator, Operator):
+class RemoveRepresentationItem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_representation_item"
     bl_label = "Remove Representation Item"
     bl_options = {"REGISTER", "UNDO"}
@@ -1939,7 +1933,7 @@ def poll_editing_representaiton_item_style(cls, context):
     return True
 
 
-class EnableEditingRepresentationItemStyle(bpy.types.Operator, Operator):
+class EnableEditingRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_representation_item_style"
     bl_label = "Enable Editing Representation Item Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1961,7 +1955,7 @@ class EnableEditingRepresentationItemStyle(bpy.types.Operator, Operator):
             props.representation_item_style = str(style.id())
 
 
-class EditRepresentationItemStyle(bpy.types.Operator, Operator):
+class EditRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_representation_item_style"
     bl_label = "Edit Representation Item Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1983,7 +1977,7 @@ class EditRepresentationItemStyle(bpy.types.Operator, Operator):
         bpy.ops.bim.enable_editing_representation_items()
 
 
-class DisableEditingRepresentationItemStyle(bpy.types.Operator, Operator):
+class DisableEditingRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_representation_item_style"
     bl_label = "Disable Editing Representation Item Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -1993,7 +1987,7 @@ class DisableEditingRepresentationItemStyle(bpy.types.Operator, Operator):
         props.is_editing_item_style = False
 
 
-class UnassignRepresentationItemStyle(bpy.types.Operator, Operator):
+class UnassignRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_representation_item_style"
     bl_label = "Unassign Representation Item Style"
     bl_options = {"REGISTER", "UNDO"}
@@ -2021,7 +2015,7 @@ class UnassignRepresentationItemStyle(bpy.types.Operator, Operator):
         bpy.ops.bim.enable_editing_representation_items()
 
 
-class EnableEditingRepresentationItemShapeAspect(bpy.types.Operator, Operator):
+class EnableEditingRepresentationItemShapeAspect(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_representation_item_shape_aspect"
     bl_label = "Enable Editing Representation Item Shape Aspect"
     bl_options = {"REGISTER", "UNDO"}
@@ -2036,7 +2030,7 @@ class EnableEditingRepresentationItemShapeAspect(bpy.types.Operator, Operator):
             props.representation_item_shape_aspect = str(shape_aspect_id)
 
 
-class EditRepresentationItemShapeAspect(bpy.types.Operator, Operator):
+class EditRepresentationItemShapeAspect(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_representation_item_shape_aspect"
     bl_label = "Edit Representation Item Shape Aspect"
     bl_options = {"REGISTER", "UNDO"}
@@ -2092,7 +2086,7 @@ class EditRepresentationItemShapeAspect(bpy.types.Operator, Operator):
         bpy.ops.bim.enable_editing_representation_items()
 
 
-class DisableEditingRepresentationItemShapeAspect(bpy.types.Operator, Operator):
+class DisableEditingRepresentationItemShapeAspect(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_representation_item_shape_aspect"
     bl_label = "Disable Editing Representation Item Shape Aspect"
     bl_options = {"REGISTER", "UNDO"}
@@ -2102,7 +2096,7 @@ class DisableEditingRepresentationItemShapeAspect(bpy.types.Operator, Operator):
         props.is_editing_item_shape_aspect = False
 
 
-class RemoveRepresentationItemFromShapeAspect(bpy.types.Operator, Operator):
+class RemoveRepresentationItemFromShapeAspect(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_representation_item_from_shape_aspect"
     bl_label = "Remove Representation Item From Shape Aspect"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/library/operator.py

@@ -24,14 +24,7 @@ import blenderbim.bim.handler
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class AddLibrary(bpy.types.Operator, Operator):
+class AddLibrary(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_library"
     bl_label = "Add Library"
     bl_options = {"REGISTER", "UNDO"}
@@ -40,7 +33,7 @@ class AddLibrary(bpy.types.Operator, Operator):
         core.add_library(tool.Ifc)
 
 
-class RemoveLibrary(bpy.types.Operator, Operator):
+class RemoveLibrary(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_library"
     bl_label = "Remove Library"
     bl_options = {"REGISTER", "UNDO"}
@@ -50,7 +43,7 @@ class RemoveLibrary(bpy.types.Operator, Operator):
         core.remove_library(tool.Ifc, library=tool.Ifc.get().by_id(self.library))
 
 
-class EnableEditingLibraryReferences(bpy.types.Operator, Operator):
+class EnableEditingLibraryReferences(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_library_references"
     bl_label = "Enable Editing Library References"
     bl_options = {"REGISTER", "UNDO"}
@@ -60,7 +53,7 @@ class EnableEditingLibraryReferences(bpy.types.Operator, Operator):
         core.enable_editing_library_references(tool.Library, library=tool.Ifc.get().by_id(self.library))
 
 
-class DisableEditingLibraryReferences(bpy.types.Operator, Operator):
+class DisableEditingLibraryReferences(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_library_references"
     bl_label = "Disable Editing Library References"
     bl_options = {"REGISTER", "UNDO"}
@@ -69,7 +62,7 @@ class DisableEditingLibraryReferences(bpy.types.Operator, Operator):
         core.disable_editing_library_references(tool.Library)
 
 
-class EnableEditingLibrary(bpy.types.Operator, Operator):
+class EnableEditingLibrary(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_library"
     bl_label = "Enable Editing Library"
     bl_options = {"REGISTER", "UNDO"}
@@ -78,7 +71,7 @@ class EnableEditingLibrary(bpy.types.Operator, Operator):
         core.enable_editing_library(tool.Library)
 
 
-class DisableEditingLibrary(bpy.types.Operator, Operator):
+class DisableEditingLibrary(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_library"
     bl_label = "Disable Editing Library"
     bl_options = {"REGISTER", "UNDO"}
@@ -87,7 +80,7 @@ class DisableEditingLibrary(bpy.types.Operator, Operator):
         core.disable_editing_library(tool.Library)
 
 
-class EditLibrary(bpy.types.Operator, Operator):
+class EditLibrary(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_library"
     bl_label = "Edit Library"
     bl_options = {"REGISTER", "UNDO"}
@@ -96,7 +89,7 @@ class EditLibrary(bpy.types.Operator, Operator):
         core.edit_library(tool.Ifc, tool.Library)
 
 
-class AddLibraryReference(bpy.types.Operator, Operator):
+class AddLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_library_reference"
     bl_label = "Add Library Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -105,7 +98,7 @@ class AddLibraryReference(bpy.types.Operator, Operator):
         core.add_library_reference(tool.Ifc, tool.Library)
 
 
-class RemoveLibraryReference(bpy.types.Operator, Operator):
+class RemoveLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_library_reference"
     bl_label = "Remove Library Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -115,7 +108,7 @@ class RemoveLibraryReference(bpy.types.Operator, Operator):
         core.remove_library_reference(tool.Ifc, tool.Library, reference=tool.Ifc.get().by_id(self.reference))
 
 
-class EnableEditingLibraryReference(bpy.types.Operator, Operator):
+class EnableEditingLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_library_reference"
     bl_label = "Enable Editing Library Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -125,7 +118,7 @@ class EnableEditingLibraryReference(bpy.types.Operator, Operator):
         core.enable_editing_library_reference(tool.Library, reference=tool.Ifc.get().by_id(self.reference))
 
 
-class DisableEditingLibraryReference(bpy.types.Operator, Operator):
+class DisableEditingLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_library_reference"
     bl_label = "Disable Editing Library Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -134,7 +127,7 @@ class DisableEditingLibraryReference(bpy.types.Operator, Operator):
         core.disable_editing_library_reference(tool.Library)
 
 
-class EditLibraryReference(bpy.types.Operator, Operator):
+class EditLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_library_reference"
     bl_label = "Edit Library Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -143,7 +136,7 @@ class EditLibraryReference(bpy.types.Operator, Operator):
         core.edit_library_reference(tool.Ifc, tool.Library)
 
 
-class AssignLibraryReference(bpy.types.Operator, Operator):
+class AssignLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_library_reference"
     bl_label = "Assign Library Reference"
     bl_options = {"REGISTER", "UNDO"}
@@ -155,7 +148,7 @@ class AssignLibraryReference(bpy.types.Operator, Operator):
         )
 
 
-class UnassignLibraryReference(bpy.types.Operator, Operator):
+class UnassignLibraryReference(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_library_reference"
     bl_label = "Unassign Library Reference"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/misc/operator.py

@@ -28,13 +28,6 @@ from blenderbim.bim.ifc import IfcStore
 from mathutils import Vector, Matrix, Euler
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class SetOverrideColour(bpy.types.Operator):
     bl_idname = "bim.set_override_colour"
     bl_label = "Set Override Colour"
@@ -117,7 +110,7 @@ class SnapSpacesTogether(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class ResizeToStorey(bpy.types.Operator, Operator):
+class ResizeToStorey(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.resize_to_storey"
     bl_label = "Resize To Storey"
     bl_options = {"REGISTER", "UNDO"}
@@ -132,7 +125,7 @@ class ResizeToStorey(bpy.types.Operator, Operator):
             core.resize_to_storey(tool.Misc, obj=obj, total_storeys=self.total_storeys)
 
 
-class SplitAlongEdge(bpy.types.Operator, Operator):
+class SplitAlongEdge(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.split_along_edge"
     bl_label = "Split Along Edge"
     bl_description = (
@@ -206,7 +199,7 @@ class SplitAlongEdge(bpy.types.Operator, Operator):
         self.report({"INFO"}, f"Splitting finished, {len(new_objs)} new objects created.")
 
 
-class GetConnectedSystemElements(bpy.types.Operator, Operator):
+class GetConnectedSystemElements(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.get_connected_system_elements"
     bl_label = "Get Connected System Elements"
     bl_options = {"REGISTER", "UNDO"}
@@ -258,7 +251,7 @@ class GetConnectedSystemElements(bpy.types.Operator, Operator):
                 obj.select_set(True)
 
 
-class DrawSystemArrows(bpy.types.Operator, Operator):
+class DrawSystemArrows(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.draw_system_arrows"
     bl_label = "Draw System Arrows"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/nest/operator.py

@@ -26,14 +26,7 @@ import blenderbim.bim.handler
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class BIM_OT_nest_assign_object(bpy.types.Operator, Operator):
+class BIM_OT_nest_assign_object(bpy.types.Operator, tool.Ifc.Operator):
     """Create nest relationship between two ifc elements"""
 
     bl_idname = "bim.nest_assign_object"
@@ -67,7 +60,7 @@ class BIM_OT_nest_assign_object(bpy.types.Operator, Operator):
                 self.report({"ERROR"}, f" Cannot nest {obj.name} to {relating_obj.name}")
 
 
-class BIM_OT_nest_unassign_object(bpy.types.Operator, Operator):
+class BIM_OT_nest_unassign_object(bpy.types.Operator, tool.Ifc.Operator):
     """Remove nest relationship between two ifc elements"""
 
     bl_idname = "bim.nest_unassign_object"
@@ -91,7 +84,7 @@ class BIM_OT_nest_unassign_object(bpy.types.Operator, Operator):
             )
 
 
-class BIM_OT_enable_editing_nest(bpy.types.Operator, Operator):
+class BIM_OT_enable_editing_nest(bpy.types.Operator, tool.Ifc.Operator):
     """Enable editing nest relationship"""
 
     bl_idname = "bim.enable_editing_nest"
@@ -102,7 +95,7 @@ class BIM_OT_enable_editing_nest(bpy.types.Operator, Operator):
         core.enable_editing_nest(tool.Nest, obj=context.active_object)
 
 
-class BIM_OT_disable_editing_nest(bpy.types.Operator, Operator):
+class BIM_OT_disable_editing_nest(bpy.types.Operator, tool.Ifc.Operator):
     """Disable editing nest relationship"""
 
     bl_idname = "bim.disable_editing_nest"

src/blenderbim/blenderbim/bim/module/owner/operator.py

@@ -23,14 +23,7 @@ import blenderbim.bim.handler
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class EnableEditingPerson(bpy.types.Operator, Operator):
+class EnableEditingPerson(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_person"
     bl_label = "Enable Editing Person"
     bl_options = {"REGISTER", "UNDO"}
@@ -40,7 +33,7 @@ class EnableEditingPerson(bpy.types.Operator, Operator):
         core.enable_editing_person(tool.Owner, person=tool.Ifc.get().by_id(self.person))
 
 
-class DisableEditingPerson(bpy.types.Operator, Operator):
+class DisableEditingPerson(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_person"
     bl_label = "Disable Editing Person"
     bl_options = {"REGISTER", "UNDO"}
@@ -49,7 +42,7 @@ class DisableEditingPerson(bpy.types.Operator, Operator):
         core.disable_editing_person(tool.Owner)
 
 
-class AddPerson(bpy.types.Operator, Operator):
+class AddPerson(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_person"
     bl_label = "Add Person"
     bl_options = {"REGISTER", "UNDO"}
@@ -58,7 +51,7 @@ class AddPerson(bpy.types.Operator, Operator):
         core.add_person(tool.Ifc)
 
 
-class EditPerson(bpy.types.Operator, Operator):
+class EditPerson(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_person"
     bl_label = "Edit Person"
     bl_options = {"REGISTER", "UNDO"}
@@ -67,7 +60,7 @@ class EditPerson(bpy.types.Operator, Operator):
         core.edit_person(tool.Ifc, tool.Owner)
 
 
-class RemovePerson(bpy.types.Operator, Operator):
+class RemovePerson(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_person"
     bl_label = "Remove Person"
     bl_options = {"REGISTER", "UNDO"}
@@ -77,7 +70,7 @@ class RemovePerson(bpy.types.Operator, Operator):
         core.remove_person(tool.Ifc, person=tool.Ifc.get().by_id(self.person))
 
 
-class AddPersonAttribute(bpy.types.Operator, Operator):
+class AddPersonAttribute(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_person_attribute"
     bl_label = "Add Person Attribute"
     bl_options = {"REGISTER", "UNDO"}
@@ -87,7 +80,7 @@ class AddPersonAttribute(bpy.types.Operator, Operator):
         core.add_person_attribute(tool.Owner, name=self.name)
 
 
-class RemovePersonAttribute(bpy.types.Operator, Operator):
+class RemovePersonAttribute(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_person_attribute"
     bl_label = "Remove Person Attribute"
     bl_options = {"REGISTER", "UNDO"}
@@ -98,7 +91,7 @@ class RemovePersonAttribute(bpy.types.Operator, Operator):
         core.remove_person_attribute(tool.Owner, name=self.name, id=self.id)
 
 
-class EnableEditingRole(bpy.types.Operator, Operator):
+class EnableEditingRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_role"
     bl_label = "Enable Editing Role"
     bl_options = {"REGISTER", "UNDO"}
@@ -108,7 +101,7 @@ class EnableEditingRole(bpy.types.Operator, Operator):
         core.enable_editing_role(tool.Owner, role=tool.Ifc.get().by_id(self.role))
 
 
-class DisableEditingRole(bpy.types.Operator, Operator):
+class DisableEditingRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_role"
     bl_label = "Disable Editing Role"
     bl_options = {"REGISTER", "UNDO"}
@@ -117,7 +110,7 @@ class DisableEditingRole(bpy.types.Operator, Operator):
         core.disable_editing_role(tool.Owner)
 
 
-class AddRole(bpy.types.Operator, Operator):
+class AddRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_role"
     bl_label = "Add Role"
     bl_options = {"REGISTER", "UNDO"}
@@ -127,7 +120,7 @@ class AddRole(bpy.types.Operator, Operator):
         core.add_role(tool.Ifc, parent=tool.Ifc.get().by_id(self.parent))
 
 
-class EditRole(bpy.types.Operator, Operator):
+class EditRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_role"
     bl_label = "Edit Role"
     bl_options = {"REGISTER", "UNDO"}
@@ -136,7 +129,7 @@ class EditRole(bpy.types.Operator, Operator):
         core.edit_role(tool.Ifc, tool.Owner)
 
 
-class RemoveRole(bpy.types.Operator, Operator):
+class RemoveRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_role"
     bl_label = "Remove Role"
     bl_options = {"REGISTER", "UNDO"}
@@ -146,7 +139,7 @@ class RemoveRole(bpy.types.Operator, Operator):
         core.remove_role(tool.Ifc, role=tool.Ifc.get().by_id(self.role))
 
 
-class AddAddress(bpy.types.Operator, Operator):
+class AddAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_address"
     bl_label = "Add Address"
     bl_options = {"REGISTER", "UNDO"}
@@ -157,7 +150,7 @@ class AddAddress(bpy.types.Operator, Operator):
         core.add_address(tool.Ifc, parent=tool.Ifc.get().by_id(self.parent), ifc_class=self.ifc_class)
 
 
-class AddAddressAttribute(bpy.types.Operator, Operator):
+class AddAddressAttribute(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_address_attribute"
     bl_label = "Add Address Attribute"
     bl_options = {"REGISTER", "UNDO"}
@@ -167,7 +160,7 @@ class AddAddressAttribute(bpy.types.Operator, Operator):
         core.add_address_attribute(tool.Owner, name=self.name)
 
 
-class RemoveAddressAttribute(bpy.types.Operator, Operator):
+class RemoveAddressAttribute(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_address_attribute"
     bl_label = "Remove Address Attribute"
     bl_options = {"REGISTER", "UNDO"}
@@ -178,7 +171,7 @@ class RemoveAddressAttribute(bpy.types.Operator, Operator):
         core.remove_address_attribute(tool.Owner, name=self.name, id=self.id)
 
 
-class EnableEditingAddress(bpy.types.Operator, Operator):
+class EnableEditingAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_address"
     bl_label = "Enable Editing Address"
     bl_options = {"REGISTER", "UNDO"}
@@ -188,7 +181,7 @@ class EnableEditingAddress(bpy.types.Operator, Operator):
         core.enable_editing_address(tool.Owner, address=tool.Ifc.get().by_id(self.address))
 
 
-class DisableEditingAddress(bpy.types.Operator, Operator):
+class DisableEditingAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_address"
     bl_label = "Disable Editing Address"
     bl_options = {"REGISTER", "UNDO"}
@@ -197,7 +190,7 @@ class DisableEditingAddress(bpy.types.Operator, Operator):
         core.disable_editing_address(tool.Owner)
 
 
-class EditAddress(bpy.types.Operator, Operator):
+class EditAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_address"
     bl_label = "Edit Address"
     bl_options = {"REGISTER", "UNDO"}
@@ -206,7 +199,7 @@ class EditAddress(bpy.types.Operator, Operator):
         core.edit_address(tool.Ifc, tool.Owner)
 
 
-class RemoveAddress(bpy.types.Operator, Operator):
+class RemoveAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_address"
     bl_label = "Remove Address"
     bl_options = {"REGISTER", "UNDO"}
@@ -216,7 +209,7 @@ class RemoveAddress(bpy.types.Operator, Operator):
         core.remove_address(tool.Ifc, address=tool.Ifc.get().by_id(self.address))
 
 
-class EnableEditingOrganisation(bpy.types.Operator, Operator):
+class EnableEditingOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_organisation"
     bl_label = "Enable Editing Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -226,7 +219,7 @@ class EnableEditingOrganisation(bpy.types.Operator, Operator):
         core.enable_editing_organisation(tool.Owner, organisation=tool.Ifc.get().by_id(self.organisation))
 
 
-class DisableEditingOrganisation(bpy.types.Operator, Operator):
+class DisableEditingOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_organisation"
     bl_label = "Disable Editing Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -235,7 +228,7 @@ class DisableEditingOrganisation(bpy.types.Operator, Operator):
         core.disable_editing_organisation(tool.Owner)
 
 
-class AddOrganisation(bpy.types.Operator, Operator):
+class AddOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_organisation"
     bl_label = "Add Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -244,7 +237,7 @@ class AddOrganisation(bpy.types.Operator, Operator):
         core.add_organisation(tool.Ifc)
 
 
-class EditOrganisation(bpy.types.Operator, Operator):
+class EditOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_organisation"
     bl_label = "Edit Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -253,7 +246,7 @@ class EditOrganisation(bpy.types.Operator, Operator):
         core.edit_organisation(tool.Ifc, tool.Owner)
 
 
-class RemoveOrganisation(bpy.types.Operator, Operator):
+class RemoveOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_organisation"
     bl_label = "Remove Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -263,7 +256,7 @@ class RemoveOrganisation(bpy.types.Operator, Operator):
         core.remove_organisation(tool.Ifc, tool.Ifc.get().by_id(self.organisation))
 
 
-class AddPersonAndOrganisation(bpy.types.Operator, Operator):
+class AddPersonAndOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_person_and_organisation"
     bl_label = "Add Person And Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -276,7 +269,7 @@ class AddPersonAndOrganisation(bpy.types.Operator, Operator):
         )
 
 
-class RemovePersonAndOrganisation(bpy.types.Operator, Operator):
+class RemovePersonAndOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_person_and_organisation"
     bl_label = "Remove Person And Organisation"
     bl_options = {"REGISTER", "UNDO"}
@@ -288,7 +281,7 @@ class RemovePersonAndOrganisation(bpy.types.Operator, Operator):
         )
 
 
-class SetUser(bpy.types.Operator, Operator):
+class SetUser(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.set_user"
     bl_label = "Set User"
     bl_options = {"REGISTER", "UNDO"}
@@ -298,7 +291,7 @@ class SetUser(bpy.types.Operator, Operator):
         core.set_user(tool.Owner, user=tool.Ifc.get().by_id(self.user))
 
 
-class ClearUser(bpy.types.Operator, Operator):
+class ClearUser(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.clear_user"
     bl_label = "Clear User"
     bl_options = {"REGISTER", "UNDO"}
@@ -308,7 +301,7 @@ class ClearUser(bpy.types.Operator, Operator):
         core.clear_user(tool.Owner)
 
 
-class AddActor(bpy.types.Operator, Operator):
+class AddActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_actor"
     bl_label = "Add Actor"
     bl_options = {"REGISTER", "UNDO"}
@@ -319,7 +312,7 @@ class AddActor(bpy.types.Operator, Operator):
             core.add_actor(tool.Ifc, ifc_class=props.actor_class, actor=tool.Ifc.get().by_id(int(props.the_actor)))
 
 
-class EnableEditingActor(bpy.types.Operator, Operator):
+class EnableEditingActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_actor"
     bl_label = "Enable Editing Actor"
     bl_options = {"REGISTER", "UNDO"}
@@ -329,7 +322,7 @@ class EnableEditingActor(bpy.types.Operator, Operator):
         core.enable_editing_actor(tool.Owner, actor=tool.Ifc.get().by_id(self.actor))
 
 
-class DisableEditingActor(bpy.types.Operator, Operator):
+class DisableEditingActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_actor"
     bl_label = "Disable Editing Actor"
     bl_options = {"REGISTER", "UNDO"}
@@ -338,7 +331,7 @@ class DisableEditingActor(bpy.types.Operator, Operator):
         core.disable_editing_actor(tool.Owner)
 
 
-class EditActor(bpy.types.Operator, Operator):
+class EditActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_actor"
     bl_label = "Edit Actor"
     bl_options = {"REGISTER", "UNDO"}
@@ -347,7 +340,7 @@ class EditActor(bpy.types.Operator, Operator):
         core.edit_actor(tool.Ifc, tool.Owner)
 
 
-class RemoveActor(bpy.types.Operator, Operator):
+class RemoveActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_actor"
     bl_label = "Remove Actor"
     bl_options = {"REGISTER", "UNDO"}
@@ -357,7 +350,7 @@ class RemoveActor(bpy.types.Operator, Operator):
         core.remove_actor(tool.Ifc, actor=tool.Ifc.get().by_id(self.actor))
 
 
-class AssignActor(bpy.types.Operator, Operator):
+class AssignActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_actor"
     bl_label = "Assign Actor"
     bl_options = {"REGISTER", "UNDO"}
@@ -369,7 +362,7 @@ class AssignActor(bpy.types.Operator, Operator):
         )
 
 
-class UnassignActor(bpy.types.Operator, Operator):
+class UnassignActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_actor"
     bl_label = "Unassign Actor"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/pset/operator.py

@@ -31,14 +31,7 @@ import blenderbim.bim.module.pset.data
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class TogglePsetExpansion(bpy.types.Operator, Operator):
+class TogglePsetExpansion(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.toggle_pset_expansion"
     bl_label = "Toggle Pset Expansion"
     pset_id: bpy.props.IntProperty()
@@ -70,7 +63,7 @@ class EnablePsetEditing(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class DisablePsetEditing(bpy.types.Operator, Operator):
+class DisablePsetEditing(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_pset_editing"
     bl_label = "Disable Pset Editing"
     bl_options = {"REGISTER", "UNDO"}
@@ -91,7 +84,7 @@ class DisablePsetEditing(bpy.types.Operator, Operator):
         props.active_pset_type = ""
 
 
-class EditPset(bpy.types.Operator, Operator):
+class EditPset(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_pset"
     bl_label = "Edit Pset"
     bl_options = {"REGISTER", "UNDO"}
@@ -159,7 +152,7 @@ class EditPset(bpy.types.Operator, Operator):
         tool.Blender.update_viewport()
 
 
-class RemovePset(bpy.types.Operator, Operator):
+class RemovePset(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_pset"
     bl_label = "Remove Pset"
     bl_options = {"REGISTER", "UNDO"}
@@ -187,7 +180,7 @@ class RemovePset(bpy.types.Operator, Operator):
                 )
 
 
-class AddPset(bpy.types.Operator, Operator):
+class AddPset(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_pset"
     bl_label = "Add Pset"
     bl_options = {"REGISTER", "UNDO"}
@@ -198,7 +191,7 @@ class AddPset(bpy.types.Operator, Operator):
         core.add_pset(tool.Ifc, tool.Pset, tool.Blender, obj_name=self.obj, obj_type=self.obj_type)
 
 
-class AddQto(bpy.types.Operator, Operator):
+class AddQto(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_qto"
     bl_label = "Add Qto"
     bl_options = {"REGISTER", "UNDO"}
@@ -214,7 +207,7 @@ class AddQto(bpy.types.Operator, Operator):
         )
 
 
-class CopyPropertyToSelection(bpy.types.Operator, Operator):
+class CopyPropertyToSelection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.copy_property_to_selection"
     bl_label = "Copy Property To Selection"
     name: bpy.props.StringProperty()

src/blenderbim/blenderbim/bim/module/pset_template/operator.py

@@ -24,9 +24,13 @@ import blenderbim.bim.schema
 import blenderbim.bim.handler
 import blenderbim.tool as tool
 from blenderbim.bim.ifc import IfcStore
+from typing import final
 
 
-class Operator:
+class PsetTemplateOperator:
+    """`tool.Ifc.Operator` but for pset template file."""
+
+    @final
     def execute(self, context):
         IfcStore.begin_transaction(self)
         IfcStore.pset_template_file.begin_transaction()
@@ -43,6 +47,9 @@ class Operator:
     def commit(self, data):
         IfcStore.pset_template_file.redo()
 
+    def _execute(self, context: bpy.types.Context) -> None:
+        tool.Ifc.Operator._execute(self, context)
+
 
 class AddPsetTemplateFile(bpy.types.Operator):
     bl_idname = "bim.add_pset_template_file"
@@ -70,7 +77,7 @@ class AddPsetTemplateFile(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class AddPsetTemplate(bpy.types.Operator, Operator):
+class AddPsetTemplate(bpy.types.Operator, PsetTemplateOperator):
     bl_idname = "bim.add_pset_template"
     bl_label = "Add Pset Template"
     bl_options = {"REGISTER", "UNDO"}
@@ -84,7 +91,7 @@ class AddPsetTemplate(bpy.types.Operator, Operator):
         context.scene.BIMPsetTemplateProperties.pset_templates = str(template.id())
 
 
-class RemovePsetTemplate(bpy.types.Operator, Operator):
+class RemovePsetTemplate(bpy.types.Operator, PsetTemplateOperator):
     bl_idname = "bim.remove_pset_template"
     bl_label = "Remove Pset Template"
     bl_options = {"REGISTER", "UNDO"}
@@ -191,7 +198,7 @@ class DisableEditingPropTemplate(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class EditPsetTemplate(bpy.types.Operator, Operator):
+class EditPsetTemplate(bpy.types.Operator, PsetTemplateOperator):
     bl_idname = "bim.edit_pset_template"
     bl_label = "Edit Pset Template"
     bl_options = {"REGISTER", "UNDO"}
@@ -242,7 +249,7 @@ class RemovePsetTemplateFile(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class AddPropTemplate(bpy.types.Operator, Operator):
+class AddPropTemplate(bpy.types.Operator, PsetTemplateOperator):
     bl_idname = "bim.add_prop_template"
     bl_label = "Add Prop Template"
     bl_options = {"REGISTER", "UNDO"}
@@ -261,7 +268,7 @@ class AddPropTemplate(bpy.types.Operator, Operator):
         blenderbim.bim.schema.reload(tool.Ifc.get().schema)
 
 
-class RemovePropTemplate(bpy.types.Operator, Operator):
+class RemovePropTemplate(bpy.types.Operator, PsetTemplateOperator):
     bl_idname = "bim.remove_prop_template"
     bl_label = "Remove Prop Template"
     bl_options = {"REGISTER", "UNDO"}
@@ -278,7 +285,7 @@ class RemovePropTemplate(bpy.types.Operator, Operator):
         blenderbim.bim.schema.reload(tool.Ifc.get().schema)
 
 
-class EditPropTemplate(bpy.types.Operator, Operator):
+class EditPropTemplate(bpy.types.Operator, PsetTemplateOperator):
     bl_idname = "bim.edit_prop_template"
     bl_label = "Edit Prop Template"
     bl_options = {"REGISTER", "UNDO"}
@@ -301,7 +308,7 @@ class EditPropTemplate(bpy.types.Operator, Operator):
                 "PrimaryMeasureType": props.active_prop_template.primary_measure_type,
                 "TemplateType": props.active_prop_template.template_type,
                 "Enumerators": enumerators,
-            }
+            },
         )
         bpy.ops.bim.disable_editing_prop_template()
         IfcStore.pset_template_file.write(IfcStore.pset_template_path)

src/blenderbim/blenderbim/bim/module/root/operator.py

@@ -34,13 +34,6 @@ from blenderbim.bim.ifc import IfcStore
 from blenderbim.bim.helper import get_enum_items
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class EnableReassignClass(bpy.types.Operator):
     bl_idname = "bim.enable_reassign_class"
     bl_label = "Enable Reassign IFC Class"
@@ -169,7 +162,7 @@ class ReassignClass(bpy.types.Operator):
         return {"FINISHED"}
 
 
-class AssignClass(bpy.types.Operator, Operator):
+class AssignClass(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_class"
     bl_label = "Assign IFC Class"
     bl_options = {"REGISTER", "UNDO"}
@@ -297,7 +290,7 @@ class UnlinkObject(bpy.types.Operator):
         return context.window_manager.invoke_props_dialog(self)
 
 
-class CopyClass(bpy.types.Operator, Operator):
+class CopyClass(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.copy_class"
     bl_label = "Copy Class"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/spatial/workspace.py

@@ -27,14 +27,6 @@ import blenderbim.bim.handler
 import blenderbim.core.spatial
 
 
-# declaring it here to avoid circular import problems
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class SpatialTool(WorkSpaceTool):
     bl_space_type = "VIEW_3D"
     bl_context_mode = "OBJECT"
@@ -129,7 +121,7 @@ class SpatialToolUI:
         pass
 
 
-class Hotkey(bpy.types.Operator, Operator):
+class Hotkey(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.spatial_hotkey"
     bl_label = "Hotkey"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/structural/workspace.py

@@ -26,14 +26,6 @@ from blenderbim.bim.ifc import IfcStore
 import blenderbim.bim.handler
 
 
-# declaring it here to avoid circular import problems
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
 class StructuralTool(WorkSpaceTool):
     bl_space_type = "VIEW_3D"
     bl_context_mode = "OBJECT"
@@ -95,7 +87,7 @@ class StructuralToolUI:
         pass
 
 
-class Hotkey(bpy.types.Operator, Operator):
+class Hotkey(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.structural_hotkey"
     bl_label = "Hotkey"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/system/operator.py

@@ -27,14 +27,7 @@ from blenderbim.bim.module.system.data import PortData
 from mathutils import Matrix
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class LoadSystems(bpy.types.Operator, Operator):
+class LoadSystems(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_systems"
     bl_label = "Load Systems"
     bl_options = {"REGISTER", "UNDO"}
@@ -43,7 +36,7 @@ class LoadSystems(bpy.types.Operator, Operator):
         core.load_systems(tool.System)
 
 
-class DisableSystemEditingUI(bpy.types.Operator, Operator):
+class DisableSystemEditingUI(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_system_editing_ui"
     bl_label = "Disable System Editing UI"
     bl_options = {"REGISTER", "UNDO"}
@@ -52,7 +45,7 @@ class DisableSystemEditingUI(bpy.types.Operator, Operator):
         core.disable_system_editing_ui(tool.System)
 
 
-class AddSystem(bpy.types.Operator, Operator):
+class AddSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_system"
     bl_label = "Add System"
     bl_options = {"REGISTER", "UNDO"}
@@ -61,7 +54,7 @@ class AddSystem(bpy.types.Operator, Operator):
         core.add_system(tool.Ifc, tool.System, ifc_class=context.scene.BIMSystemProperties.system_class)
 
 
-class EditSystem(bpy.types.Operator, Operator):
+class EditSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_system"
     bl_label = "Edit System"
     bl_options = {"REGISTER", "UNDO"}
@@ -72,7 +65,7 @@ class EditSystem(bpy.types.Operator, Operator):
         )
 
 
-class RemoveSystem(bpy.types.Operator, Operator):
+class RemoveSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_system"
     bl_label = "Remove System"
     bl_options = {"REGISTER", "UNDO"}
@@ -82,7 +75,7 @@ class RemoveSystem(bpy.types.Operator, Operator):
         core.remove_system(tool.Ifc, tool.System, system=tool.Ifc.get().by_id(self.system))
 
 
-class EnableEditingSystem(bpy.types.Operator, Operator):
+class EnableEditingSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_system"
     bl_label = "Enable Editing System"
     bl_options = {"REGISTER", "UNDO"}
@@ -92,7 +85,7 @@ class EnableEditingSystem(bpy.types.Operator, Operator):
         core.enable_editing_system(tool.System, system=tool.Ifc.get().by_id(self.system))
 
 
-class DisableEditingSystem(bpy.types.Operator, Operator):
+class DisableEditingSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_system"
     bl_label = "Disable Editing System"
     bl_options = {"REGISTER", "UNDO"}
@@ -101,7 +94,7 @@ class DisableEditingSystem(bpy.types.Operator, Operator):
         core.disable_editing_system(tool.System)
 
 
-class AssignSystem(bpy.types.Operator, Operator):
+class AssignSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_system"
     bl_label = "Assign System"
     bl_options = {"REGISTER", "UNDO"}
@@ -114,7 +107,7 @@ class AssignSystem(bpy.types.Operator, Operator):
                 core.assign_system(tool.Ifc, system=tool.Ifc.get().by_id(self.system), product=element)
 
 
-class UnassignSystem(bpy.types.Operator, Operator):
+class UnassignSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_system"
     bl_label = "Unassign System"
     bl_options = {"REGISTER", "UNDO"}
@@ -127,7 +120,7 @@ class UnassignSystem(bpy.types.Operator, Operator):
                 core.unassign_system(tool.Ifc, system=tool.Ifc.get().by_id(self.system), product=element)
 
 
-class SelectSystemProducts(bpy.types.Operator, Operator):
+class SelectSystemProducts(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.select_system_products"
     bl_label = "Select System Products"
     bl_options = {"REGISTER", "UNDO"}
@@ -137,7 +130,7 @@ class SelectSystemProducts(bpy.types.Operator, Operator):
         core.select_system_products(tool.System, system=tool.Ifc.get().by_id(self.system))
 
 
-class ShowPorts(bpy.types.Operator, Operator):
+class ShowPorts(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.show_ports"
     bl_label = "Show Ports"
     bl_options = {"REGISTER", "UNDO"}
@@ -155,7 +148,7 @@ class ShowPorts(bpy.types.Operator, Operator):
         core.show_ports(tool.Ifc, tool.System, tool.Spatial, element=tool.Ifc.get_entity(context.active_object))
 
 
-class HidePorts(bpy.types.Operator, Operator):
+class HidePorts(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.hide_ports"
     bl_label = "Hide Ports"
     bl_options = {"REGISTER", "UNDO"}
@@ -168,7 +161,7 @@ class HidePorts(bpy.types.Operator, Operator):
         core.hide_ports(tool.Ifc, tool.System, element=tool.Ifc.get_entity(context.active_object))
 
 
-class AddPort(bpy.types.Operator, Operator):
+class AddPort(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_port"
     bl_description = "Add port at current cursor position"
     bl_label = "Add Port"
@@ -178,7 +171,7 @@ class AddPort(bpy.types.Operator, Operator):
         core.add_port(tool.Ifc, tool.System, element=tool.Ifc.get_entity(context.active_object))
 
 
-class RemovePort(bpy.types.Operator, Operator):
+class RemovePort(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_port"
     bl_label = "Remove Port"
     bl_options = {"REGISTER", "UNDO"}
@@ -187,7 +180,7 @@ class RemovePort(bpy.types.Operator, Operator):
         core.remove_port(tool.Ifc, tool.System, port=tool.Ifc.get_entity(context.active_object))
 
 
-class ConnectPort(bpy.types.Operator, Operator):
+class ConnectPort(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.connect_port"
     bl_label = "Connect Ports"
     bl_options = {"REGISTER", "UNDO"}
@@ -202,7 +195,7 @@ class ConnectPort(bpy.types.Operator, Operator):
         core.connect_port(tool.Ifc, port1=tool.Ifc.get_entity(obj1), port2=tool.Ifc.get_entity(obj2))
 
 
-class DisconnectPort(bpy.types.Operator, Operator):
+class DisconnectPort(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disconnect_port"
     bl_label = "Disconnect Ports"
     bl_options = {"REGISTER", "UNDO"}
@@ -217,7 +210,7 @@ class DisconnectPort(bpy.types.Operator, Operator):
         core.disconnect_port(tool.Ifc, port=element)
 
 
-class MEPConnectElements(bpy.types.Operator, Operator):
+class MEPConnectElements(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.mep_connect_elements"
     bl_label = "Connect MEP Elements"
     bl_description = "Connects two selected elements by their closest located ports and adjusts them"
@@ -268,7 +261,7 @@ class MEPConnectElements(bpy.types.Operator, Operator):
         return {"FINISHED"}
 
 
-class SetFlowDirection(bpy.types.Operator, Operator):
+class SetFlowDirection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.set_flow_direction"
     bl_label = "Set Flow Direction"
     bl_options = {"REGISTER", "UNDO"}
@@ -332,7 +325,7 @@ class SetFlowDirection(bpy.types.Operator, Operator):
         return {"CANCELLED"}
 
 
-class LoadZones(bpy.types.Operator, Operator):
+class LoadZones(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_zones"
     bl_label = "Load Zones"
     bl_options = {"REGISTER", "UNDO"}
@@ -348,7 +341,7 @@ class LoadZones(bpy.types.Operator, Operator):
         props.is_editing = 0
 
 
-class UnloadZones(bpy.types.Operator, Operator):
+class UnloadZones(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unload_zones"
     bl_label = "Unload Zones"
     bl_options = {"REGISTER", "UNDO"}
@@ -358,7 +351,7 @@ class UnloadZones(bpy.types.Operator, Operator):
         props.is_loaded = False
 
 
-class AddZone(bpy.types.Operator, Operator):
+class AddZone(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_zone"
     bl_label = "Add Zone"
     bl_options = {"REGISTER", "UNDO"}
@@ -378,7 +371,7 @@ class AddZone(bpy.types.Operator, Operator):
         bpy.ops.bim.load_zones()
 
 
-class EnableEditingZone(bpy.types.Operator, Operator):
+class EnableEditingZone(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_zone"
     bl_label = "Enable Editing Zone"
     bl_options = {"REGISTER", "UNDO"}
@@ -391,7 +384,7 @@ class EnableEditingZone(bpy.types.Operator, Operator):
         props.is_editing = self.zone
 
 
-class DisableEditingZone(bpy.types.Operator, Operator):
+class DisableEditingZone(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_zone"
     bl_label = "Disable Editing Zone"
     bl_options = {"REGISTER", "UNDO"}
@@ -401,7 +394,7 @@ class DisableEditingZone(bpy.types.Operator, Operator):
         props.is_editing = 0
 
 
-class EditZone(bpy.types.Operator, Operator):
+class EditZone(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_zone"
     bl_label = "Edit Zone"
     bl_options = {"REGISTER", "UNDO"}
@@ -415,7 +408,7 @@ class EditZone(bpy.types.Operator, Operator):
         bpy.ops.bim.load_zones()
 
 
-class RemoveZone(bpy.types.Operator, Operator):
+class RemoveZone(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_zone"
     bl_label = "Remove Zone"
     bl_options = {"REGISTER", "UNDO"}
@@ -426,7 +419,7 @@ class RemoveZone(bpy.types.Operator, Operator):
         bpy.ops.bim.load_zones()
 
 
-class AssignUnassignFlowControl(bpy.types.Operator, Operator):
+class AssignUnassignFlowControl(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_unassign_flow_control"
     bl_label = "Assign/Unassign Flow Control"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/type/operator.py

@@ -31,14 +31,7 @@ import blenderbim.core.root
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data()
-        return {"FINISHED"}
-
-
-class AssignType(bpy.types.Operator, Operator):
+class AssignType(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_type"
     bl_label = "Assign Type"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/bim/module/unit/operator.py

@@ -27,14 +27,7 @@ import blenderbim.core.unit as core
 from blenderbim.bim.ifc import IfcStore
 
 
-class Operator:
-    def execute(self, context):
-        IfcStore.execute_ifc_operator(self, context)
-        blenderbim.bim.handler.refresh_ui_data
-        return {"FINISHED"}
-
-
-class AssignSceneUnits(bpy.types.Operator, Operator):
+class AssignSceneUnits(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_scene_units"
     bl_label = "Assign Scene Units"
     bl_options = {"REGISTER", "UNDO"}
@@ -43,7 +36,7 @@ class AssignSceneUnits(bpy.types.Operator, Operator):
         core.assign_scene_units(tool.Ifc, tool.Unit)
 
 
-class AssignUnit(bpy.types.Operator, Operator):
+class AssignUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_unit"
     bl_label = "Assign Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -53,7 +46,7 @@ class AssignUnit(bpy.types.Operator, Operator):
         core.assign_unit(tool.Ifc, tool.Unit, unit=tool.Ifc.get().by_id(self.unit))
 
 
-class UnassignUnit(bpy.types.Operator, Operator):
+class UnassignUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_unit"
     bl_label = "Unassign Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -63,7 +56,7 @@ class UnassignUnit(bpy.types.Operator, Operator):
         core.unassign_unit(tool.Ifc, tool.Unit, unit=tool.Ifc.get().by_id(self.unit))
 
 
-class LoadUnits(bpy.types.Operator, Operator):
+class LoadUnits(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.load_units"
     bl_label = "Load Units"
     bl_options = {"REGISTER", "UNDO"}
@@ -73,7 +66,7 @@ class LoadUnits(bpy.types.Operator, Operator):
         core.load_units(tool.Unit)
 
 
-class DisableUnitEditingUI(bpy.types.Operator, Operator):
+class DisableUnitEditingUI(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_unit_editing_ui"
     bl_label = "Disable Unit Editing UI"
     bl_options = {"REGISTER", "UNDO"}
@@ -83,7 +76,7 @@ class DisableUnitEditingUI(bpy.types.Operator, Operator):
         core.disable_unit_editing_ui(tool.Unit)
 
 
-class RemoveUnit(bpy.types.Operator, Operator):
+class RemoveUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_unit"
     bl_label = "Remove Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -93,7 +86,7 @@ class RemoveUnit(bpy.types.Operator, Operator):
         core.remove_unit(tool.Ifc, tool.Unit, unit=tool.Ifc.get().by_id(self.unit))
 
 
-class AddConversionBasedUnit(bpy.types.Operator, Operator):
+class AddConversionBasedUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_conversion_based_unit"
     bl_label = "Add Conversion Based Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -103,7 +96,7 @@ class AddConversionBasedUnit(bpy.types.Operator, Operator):
         core.add_conversion_based_unit(tool.Ifc, tool.Unit, name=self.name)
 
 
-class AddMonetaryUnit(bpy.types.Operator, Operator):
+class AddMonetaryUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_monetary_unit"
     bl_label = "Add Monetary Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -112,7 +105,7 @@ class AddMonetaryUnit(bpy.types.Operator, Operator):
         core.add_monetary_unit(tool.Ifc, tool.Unit)
 
 
-class AddSIUnit(bpy.types.Operator, Operator):
+class AddSIUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_si_unit"
     bl_label = "Add SI Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -122,7 +115,7 @@ class AddSIUnit(bpy.types.Operator, Operator):
         core.add_si_unit(tool.Ifc, tool.Unit, unit_type=self.unit_type)
 
 
-class AddContextDependentUnit(bpy.types.Operator, Operator):
+class AddContextDependentUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_context_dependent_unit"
     bl_label = "Add Context Dependent Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -133,7 +126,7 @@ class AddContextDependentUnit(bpy.types.Operator, Operator):
         core.add_context_dependent_unit(tool.Ifc, tool.Unit, unit_type=self.unit_type, name=self.name)
 
 
-class EnableEditingUnit(bpy.types.Operator, Operator):
+class EnableEditingUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_unit"
     bl_label = "Enable Editing Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -143,7 +136,7 @@ class EnableEditingUnit(bpy.types.Operator, Operator):
         core.enable_editing_unit(tool.Unit, unit=tool.Ifc.get().by_id(self.unit))
 
 
-class DisableEditingUnit(bpy.types.Operator, Operator):
+class DisableEditingUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.disable_editing_unit"
     bl_label = "Disable Editing Unit"
     bl_options = {"REGISTER", "UNDO"}
@@ -152,7 +145,7 @@ class DisableEditingUnit(bpy.types.Operator, Operator):
         core.disable_editing_unit(tool.Unit)
 
 
-class EditUnit(bpy.types.Operator, Operator):
+class EditUnit(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_unit"
     bl_label = "Edit Unit"
     bl_options = {"REGISTER", "UNDO"}

src/blenderbim/blenderbim/tool/boundary.py

@@ -20,12 +20,15 @@ import bpy
 import mathutils
 import blenderbim.core.tool
 import blenderbim.tool as tool
-from blenderbim.bim.module.geometry.helper import Helper
+from mathutils import Matrix, Vector
+from typing import Any, Sequence
 
 
 class Boundary(blenderbim.core.tool.Boundary):
     @classmethod
-    def get_assign_connection_geometry_settings(cls, obj):
+    def get_assign_connection_geometry_settings(cls, obj: bpy.types.Object) -> dict[str, Any]:
+        from blenderbim.bim.module.geometry.helper import Helper
+
         ifc = tool.Ifc.get()
         helper = Helper(ifc)
         mesh = obj.data
@@ -55,16 +58,16 @@ class Boundary(blenderbim.core.tool.Boundary):
         }
 
     @classmethod
-    def polyline_from_indexes(cls, mesh, indexes):
+    def polyline_from_indexes(cls, mesh: bpy.types.Mesh, indexes: Sequence[int]) -> tuple[Vector, ...]:
         return tuple(mesh.vertices[i].co for i in indexes)
 
     @classmethod
-    def polyline_to_2d(cls, polyline, placement_matrix):
+    def polyline_to_2d(cls, polyline: Sequence[Vector], placement_matrix: Matrix) -> tuple[Vector, ...]:
         matrix_inv = placement_matrix.inverted()
         return tuple((matrix_inv @ v).to_2d() for v in polyline)
 
     @classmethod
-    def move_origin_to_space_origin(cls, obj):
+    def move_origin_to_space_origin(cls, obj: bpy.types.Object) -> None:
         boundary = tool.Ifc.get_entity(obj)
         space = tool.Ifc.get_object(boundary.RelatingSpace)
         translation = obj.matrix_world.translation - space.matrix_world.translation

src/blenderbim/blenderbim/tool/drawing.py

@@ -41,14 +41,8 @@ import ifcopenshell.util.element
 import ifcopenshell.util.selector
 import ifcopenshell.util.shape
 import blenderbim.bim.import_ifc
-import blenderbim.bim.module.drawing.sheeter as sheeter
-import blenderbim.bim.module.drawing.scheduler as scheduler
-import blenderbim.bim.module.drawing.annotation as annotation
-import blenderbim.bim.module.drawing.helper as helper
 import blenderbim.core.root
 from shapely.ops import unary_union
-from blenderbim.bim.module.drawing.data import FONT_SIZES, DecoratorData
-from blenderbim.bim.module.drawing.prop import get_diagram_scales, BOX_ALIGNMENT_POSITIONS, ANNOTATION_TYPES_DATA
 from lxml import etree
 from mathutils import Vector, Matrix
 from fractions import Fraction
@@ -60,6 +54,30 @@ class Drawing(blenderbim.core.tool.Drawing):
     ANNOTATION_DATA_TYPE = Literal["empty", "curve", "mesh"]
     DOCUMENT_TYPE = Literal["SCHEDULE", "REFERENCE"]
 
+    # ObjectType: annotation_name, description, icon, data_type
+    # fmt: off
+    ANNOTATION_TYPES_DATA = {
+        "DIMENSION":     ("Dimension",        "Add dimensions annotation.\nMeasurement values can be hidden through ShowDescriptionOnly property\nof BBIM_Dimension property set", "FIXED_SIZE", "curve"),
+        "ANGLE":         ("Angle",            "", "DRIVER_ROTATIONAL_DIFFERENCE", "curve"),
+        "RADIUS":        ("Radius",           "", "FORWARD", "curve"),
+        "DIAMETER":      ("Diameter",         "Add diameter annotation.\nMeasurement values can be hidden through ShowDescriptionOnly property\nof BBIM_Dimension property set", "ARROW_LEFTRIGHT", "curve"),
+        "TEXT":          ("Text",             "", "SMALL_CAPS", "empty"),
+        "TEXT_LEADER":   ("Leader",           "", "TRACKING_BACKWARDS", "curve"),
+        "STAIR_ARROW":   ("Stair Arrow",      "Add stair arrow annotation.\nIf you have IfcStairFlight object selected, it will be used as a reference for the annotation", "SCREEN_BACK", "curve"),
+        "PLAN_LEVEL":    ("Level (Plan)",     "", "SORTBYEXT", "curve"),
+        "SECTION_LEVEL": ("Level (Section)",  "", "TRIA_DOWN", "curve"),
+        "BREAKLINE":     ("Breakline",        "", "FCURVE", "mesh"),
+        "SYMBOL":        ("Symbol",           "", "KEYFRAME", "empty"),
+        "MULTI_SYMBOL":  ("Multi-Symbol",     "", "OUTLINER_DATA_POINTCLOUD", "mesh"),
+        "LINEWORK":      ("Line",             "", "SNAP_MIDPOINT", "mesh"),
+        "BATTING":       ("Batting",          "Add batting annotation.\nThickness could be changed through Thickness property of BBIM_Batting property set", "FORCE_FORCE", "mesh"),
+        "REVISION_CLOUD":("Revision Cloud",   "Add revision cloud", "VOLUME_DATA", "mesh"),
+        "FILL_AREA":     ("Fill Area",        "", "NODE_TEXTURE", "mesh"),
+        "FALL":          ("Fall",             "", "SORT_ASC", "curve"),
+        "IMAGE":         ("Image",            "Add reference image attached to the drawing", "TEXTURE", "mesh"),
+    }
+    # fmt: on
+
     @classmethod
     def canonicalise_class_name(cls, name):
         return re.sub("[^0-9a-zA-Z]+", "", name)
@@ -73,10 +91,12 @@ class Drawing(blenderbim.core.tool.Drawing):
 
     @classmethod
     def get_annotation_data_type(cls, object_type: str) -> ANNOTATION_DATA_TYPE:
-        return ANNOTATION_TYPES_DATA[object_type][3]
+        return cls.ANNOTATION_TYPES_DATA[object_type][3]
 
     @classmethod
     def create_annotation_object(cls, drawing: ifcopenshell.entity_instance, object_type: str) -> bpy.types.Object:
+        import blenderbim.bim.module.drawing.annotation as annotation
+
         data_type = cls.get_annotation_data_type(object_type)
         obj = annotation.Annotator.get_annotation_obj(drawing, object_type, data_type)
         if object_type == "FILL_AREA":
@@ -238,6 +258,8 @@ class Drawing(blenderbim.core.tool.Drawing):
 
     @classmethod
     def create_svg_schedule(cls, schedule):
+        import blenderbim.bim.module.drawing.scheduler as scheduler
+
         schedule_creator = scheduler.Scheduler()
         schedule_creator.schedule(
             cls.get_document_uri(schedule), cls.get_path_with_ext(cls.get_document_uri(schedule), "svg")
@@ -245,6 +267,8 @@ class Drawing(blenderbim.core.tool.Drawing):
 
     @classmethod
     def create_svg_sheet(cls, document: ifcopenshell.entity_instance, titleblock: str) -> str:
+        import blenderbim.bim.module.drawing.sheeter as sheeter
+
         sheet_builder = sheeter.SheetBuilder()
         sheet_builder.data_dir = bpy.context.scene.BIMProperties.data_dir
         uri = cls.get_document_uri(document, "LAYOUT")
@@ -253,6 +277,8 @@ class Drawing(blenderbim.core.tool.Drawing):
 
     @classmethod
     def add_drawings(cls, sheet):
+        import blenderbim.bim.module.drawing.sheeter as sheeter
+
         sheet_builder = sheeter.SheetBuilder()
         sheet_builder.data_dir = bpy.context.scene.BIMProperties.data_dir
         drawing_references = {}
@@ -707,7 +733,9 @@ class Drawing(blenderbim.core.tool.Drawing):
         return obj
 
     @classmethod
-    def import_camera_props(cls, drawing, obj):
+    def import_camera_props(cls, drawing: ifcopenshell.entity_instance, obj: bpy.types.Object) -> None:
+        from blenderbim.bim.module.drawing.prop import get_diagram_scales
+
         # Temporarily clear the definition id to prevent prop update callbacks to IFC.
         ifc_definition_id = obj.BIMObjectProperties.ifc_definition_id
         obj.BIMObjectProperties.ifc_definition_id = 0
@@ -749,7 +777,7 @@ class Drawing(blenderbim.core.tool.Drawing):
         obj.BIMObjectProperties.ifc_definition_id = ifc_definition_id
 
     @classmethod
-    def import_drawings(cls):
+    def import_drawings(cls) -> None:
         props = bpy.context.scene.DocProperties
         expanded_target_views = {d.target_view for d in props.drawings if d.is_expanded}
         current_drawings_selection = {d.ifc_definition_id: d.is_selected for d in props.drawings}
@@ -846,6 +874,8 @@ class Drawing(blenderbim.core.tool.Drawing):
 
     @classmethod
     def import_text_attributes(cls, obj: bpy.types.Object) -> None:
+        from blenderbim.bim.module.drawing.prop import BOX_ALIGNMENT_POSITIONS
+
         props = obj.BIMTextProperties
         props.literals.clear()
 
@@ -859,6 +889,8 @@ class Drawing(blenderbim.core.tool.Drawing):
             literal_props.box_alignment = box_alignment_mask
             literal_props.ifc_definition_id = ifc_literal.id()
 
+        from blenderbim.bim.module.drawing.data import DecoratorData
+
         text_data = DecoratorData.get_ifc_text_data(obj)
         props.font_size = str(text_data["FontSize"])
 
@@ -947,6 +979,8 @@ class Drawing(blenderbim.core.tool.Drawing):
         """updates pset `EPset_Annotation.Classes` value
         based on current font size from `obj.BIMTextProperties.font_size`
         """
+        from blenderbim.bim.module.drawing.data import FONT_SIZES
+
         props = obj.BIMTextProperties
         element = tool.Ifc.get_entity(obj)
         # updating text font size in EPset_Annotation.Classes
@@ -1151,6 +1185,8 @@ class Drawing(blenderbim.core.tool.Drawing):
         reference_element: ifcopenshell.entity_instance,
         context: ifcopenshell.entity_instance,
     ) -> ifcopenshell.entity_instance:
+        import blenderbim.bim.module.drawing.helper as helper
+
         camera = tool.Ifc.get_object(drawing)
         bounds = helper.ortho_view_frame(camera.data) if camera.data.type == "ORTHO" else None
         reference_obj = tool.Ifc.get_object(reference_element)
@@ -1216,6 +1252,8 @@ class Drawing(blenderbim.core.tool.Drawing):
         reference_element: ifcopenshell.entity_instance,
         context: ifcopenshell.entity_instance,
     ) -> ifcopenshell.entity_instance:
+        import blenderbim.bim.module.drawing.helper as helper
+
         reference_obj = tool.Ifc.get_object(reference_element)
         reference_obj.matrix_world
         camera = tool.Ifc.get_object(drawing)
@@ -1338,6 +1376,8 @@ class Drawing(blenderbim.core.tool.Drawing):
         reference_element: ifcopenshell.entity_instance,
         context: ifcopenshell.entity_instance,
     ) -> ifcopenshell.entity_instance:
+        import blenderbim.bim.module.drawing.helper as helper
+
         target_view = tool.Drawing.get_drawing_target_view(drawing)
 
         camera = tool.Ifc.get_object(drawing)