Fix #2001. Fix bug where you could not undo deletions.

src/blenderbim/blenderbim/bim/ifc.py

@@ -186,6 +186,23 @@ class IfcStore:
                 data["guid"] = element.GlobalId
             IfcStore.commit_link_element(data)
 
+    @staticmethod
+    def delete_element(element):
+        IfcStore.deleted_ids.add(element.id())
+        if IfcStore.history:
+            data = {"id": element.id()}
+            IfcStore.history[-1]["operations"].append(
+                {"rollback": IfcStore.rollback_delete_element, "commit": IfcStore.commit_delete_element, "data": data}
+            )
+
+    @staticmethod
+    def rollback_delete_element(data):
+        IfcStore.deleted_ids.remove(data["id"])
+
+    @staticmethod
+    def commit_delete_element(data):
+        IfcStore.deleted_ids.add(data["id"])
+
     @staticmethod
     def link_element(element, obj):
         IfcStore.id_map[element.id()] = obj

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

@@ -330,7 +330,7 @@ class OverrideDeleteTrait:
     def delete_ifc_object(self, obj):
         if obj.BIMObjectProperties.ifc_definition_id:
             element = IfcStore.get_file().by_id(obj.BIMObjectProperties.ifc_definition_id)
-            IfcStore.deleted_ids.add(element.id())
+            IfcStore.delete_element(element)
             if getattr(element, "FillsVoids", None):
                 self.remove_filling(element)
             if element.is_a("IfcOpeningElement"):