update representation item style on editing/removing shape aspect

Example - https://imgur.com/a/2SxgSRH

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

@@ -1644,7 +1644,7 @@ class RemoveRepresentationItem(bpy.types.Operator, Operator):
         tool.Geometry.remove_representation_item(representation_item)
         tool.Geometry.reload_representation(obj)
 
-        # reload style ui
+        # reload items ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
 
@@ -1716,7 +1716,7 @@ class EditRepresentationItemStyle(bpy.types.Operator, Operator):
 
         tool.Style.assign_style_to_representation_item(representation_item, surface_style)
         tool.Geometry.reload_representation(obj)
-        # reload style ui
+        # reload items ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
 
@@ -1754,7 +1754,7 @@ class UnassignRepresentationItemStyle(bpy.types.Operator, Operator):
 
         tool.Style.assign_style_to_representation_item(representation_item, None)
         tool.Geometry.reload_representation(obj)
-        # reload style ui
+        # reload items ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
 
@@ -1813,7 +1813,19 @@ class EditRepresentationItemShapeAspect(bpy.types.Operator, Operator):
         shape_aspect.Name = shape_aspect_attrs.name
         shape_aspect.Description = shape_aspect_attrs.description
 
-        # reload style ui
+        shape_aspect_representation = tool.Geometry.get_shape_aspect_representation_for_item(
+            shape_aspect, representation_item
+        )
+        styles = tool.Geometry.get_shape_aspect_styles(element, shape_aspect, representation_item)
+        tool.Ifc.run(
+            "style.assign_representation_styles",
+            shape_representation=shape_aspect_representation,
+            styles=styles,
+        )
+        tool.Geometry.get_shape_aspect_styles(element, shape_aspect, representation_item)
+        tool.Geometry.reload_representation(obj)
+
+        # reload items ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
 
@@ -1835,6 +1847,7 @@ class RemoveRepresentationItemFromShapeAspect(bpy.types.Operator, Operator):
 
     def _execute(self, context):
         obj = context.active_object
+        element = tool.Ifc.get_entity(obj)
         props = obj.BIMGeometryProperties
         ifc_file = tool.Ifc.get()
 
@@ -1842,7 +1855,32 @@ class RemoveRepresentationItemFromShapeAspect(bpy.types.Operator, Operator):
         representation_item = ifc_file.by_id(representation_item_id)
         shape_aspect = ifc_file.by_id(props.items[props.active_item_index].shape_aspect_id)
 
+        # unassign items before removing items as removing items
+        # might remove shape aspect
+        if representation_item.StyledByItem:
+            styles = tool.Geometry.get_shape_aspect_styles(element, shape_aspect, representation_item)
+            self.remove_styles_from_item(representation_item, styles)
+            tool.Geometry.reload_representation(obj)
+
         tool.Geometry.remove_representation_items_from_shape_aspect([representation_item], shape_aspect)
-        # reload style ui
+
+        # reload items ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
+
+    def remove_styles_from_item(self, representation_item, styles):
+        ifc_file = tool.Ifc.get()
+        styled_item = representation_item.StyledByItem[0]
+        new_styles = [s for s in styled_item.Styles if s not in styles]
+        styled_item.Styles = new_styles
+
+        for style_ in new_styles:
+            if style_.is_a("IfcPresentationStyleAssignment"):
+                new_assignment_styles = [s for s in styled_item.Styles if s not in styles]
+                if not new_assignment_styles:
+                    ifc_file.remove(style_)
+                else:
+                    style_.Styles = new_assignment_styles
+
+        if not styled_item.Styles:
+            ifc_file.remove(styled_item)

src/blenderbim/blenderbim/tool/geometry.py

@@ -31,6 +31,7 @@ import blenderbim.bim.import_ifc
 from math import radians, pi
 from mathutils import Vector, Matrix
 from blenderbim.bim.ifc import IfcStore
+from typing import List
 
 
 class Geometry(blenderbim.core.tool.Geometry):
@@ -872,6 +873,52 @@ class Geometry(blenderbim.core.tool.Geometry):
         shape_aspect.ShapeRepresentations = shape_aspect.ShapeRepresentations + (shape_aspect_representation,)
         return shape_aspect_representation
 
+    @classmethod
+    def get_shape_aspect_representation_for_item(cls, shape_aspect, representation_item):
+        ifc_file = tool.Ifc.get()
+        for inverse in ifc_file.get_inverse(representation_item):
+            if inverse.is_a("IfcShapeRepresentation"):
+                if inverse.OfShapeAspect:
+                    if inverse.OfShapeAspect[0] == shape_aspect:
+                        return inverse
+
+    @classmethod
+    def get_shape_aspect_styles(cls, element, shape_aspect, representation_item) -> List[ifcopenshell.entity_instance]:
+        """update `representation_item` style based on styles connected to the `shape_aspect`
+        through material constituents with the same name
+        """
+        if not shape_aspect.Name:
+            return []
+
+        # get material connected to the shape aspect with material constituent name
+        material = ifcopenshell.util.element.get_material(element, should_skip_usage=True)
+        if not material or not material.is_a("IfcMaterialConstituentSet") or not material.MaterialConstituents:
+            return []
+
+        matching_constituent = next((c for c in material.MaterialConstituents if c.Name == shape_aspect.Name), None)
+        if matching_constituent is None:
+            return []
+
+        constituent_material = matching_constituent.Material
+        if not constituent_material.HasRepresentation:
+            return []
+
+        # get shape aspect representation for item
+        shape_aspect_representation = cls.get_shape_aspect_representation_for_item(shape_aspect, representation_item)
+
+        # get the styles for this context
+        material_representation = None
+        for r in constituent_material.HasRepresentation[0].Representations:
+            if r.ContextOfItems == shape_aspect_representation.ContextOfItems:
+                material_representation = r
+                break
+
+        if material_representation is None:
+            return []
+
+        styles = [s for s in tool.Ifc.get().traverse(material_representation) if s.is_a("IfcPresentationStyle")]
+        return styles
+
     @classmethod
     def delete_opening_object_placement(cls, placement):
         model = tool.Ifc.get()