create new shape aspects from UI

example - https://i.imgur.com/BJJZWrC.png

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

@@ -108,7 +108,8 @@ class RepresentationsData:
                 matching_shape_aspects.append(shape_aspect)
 
         # blender enum items
-        return [(str(s.id()), s.Name or "Unnamed", "") for s in matching_shape_aspects]
+        new_shape_aspect = [("NEW", "Create A New Shape Aspect", "")]
+        return new_shape_aspect + [(str(s.id()), s.Name or "Unnamed", "") for s in matching_shape_aspects]
 
 
 class RepresentationItemsData:

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

@@ -1692,7 +1692,7 @@ class EnableEditingRepresentationItemShapeAspect(bpy.types.Operator, Operator):
         props = context.active_object.BIMGeometryProperties
         props.is_editing_item_shape_aspect = True
 
-        # set dropdown to currently active style
+        # set dropdown to currently active shape aspect
         shape_aspect_id = props.items[props.active_item_index].shape_aspect_id
         if shape_aspect_id != 0:
             props.representation_item_shape_aspect = str(shape_aspect_id)
@@ -1705,21 +1705,36 @@ class EditRepresentationItemShapeAspect(bpy.types.Operator, Operator):
 
     def _execute(self, context):
         obj = context.active_object
+        element = tool.Ifc.get_entity(obj)
         props = obj.BIMGeometryProperties
         props.is_editing_item_shape_aspect = False
         ifc_file = tool.Ifc.get()
 
-        shape_aspect = ifc_file.by_id(int(props.representation_item_shape_aspect))
+        representation_item_id = props.items[props.active_item_index].ifc_definition_id
+        representation_item = ifc_file.by_id(representation_item_id)
+
+        if props.representation_item_shape_aspect == "NEW":
+            active_representation = tool.Geometry.get_active_representation(obj)
+            # find IfcProductRepresentationSelect based on current representation
+            if hasattr(element, "Representation"):  # IfcProduct
+                product_shape = element.Representation
+            else:  # IfcTypeProduct
+                for representation_map in element.RepresentationMaps:
+                    if representation_map.MappedRepresentation == active_representation:
+                        product_shape = representation_map
+            previous_shape_aspect_id = props.items[props.active_item_index].shape_aspect_id
+            # will be None if item didn't had a shape aspect
+            previous_shape_aspect = tool.Ifc.get_entity_by_id(previous_shape_aspect_id)
+            shape_aspect = tool.Geometry.create_shape_aspect(product_shape, active_representation, [representation_item], previous_shape_aspect)
+        else:
+            shape_aspect = ifc_file.by_id(int(props.representation_item_shape_aspect))
+            tool.Geometry.add_representation_item_to_shape_aspect([representation_item], shape_aspect)
 
         # set attributes from UI
         shape_aspect_attrs = props.shape_aspect_attrs
         shape_aspect.Name = shape_aspect_attrs.name
         shape_aspect.Description = shape_aspect_attrs.description
 
-        representation_item_id = props.items[props.active_item_index].ifc_definition_id
-        representation_item = ifc_file.by_id(representation_item_id)
-
-        tool.Geometry.add_representation_item_to_shape_aspect(representation_item, shape_aspect)
         # reload style ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
@@ -1749,7 +1764,7 @@ 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)
 
-        tool.Geometry.remove_representation_item_from_shape_aspect(representation_item, shape_aspect)
+        tool.Geometry.remove_representation_items_from_shape_aspect([representation_item], shape_aspect)
         # reload style ui
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()

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

@@ -72,9 +72,13 @@ def update_shape_aspect(self, context):
     shape_aspect_id = self.representation_item_shape_aspect
     attrs = self.shape_aspect_attrs
 
-    shape_aspect = tool.Ifc.get().by_id(int(shape_aspect_id))
+    if shape_aspect_id == "NEW":  # new shape aspect
-    attrs.name = shape_aspect.Name or ""
+        attrs.name = tool.Blender.get_blender_prop_default_value(attrs, "name")
-    attrs.description = shape_aspect.Description or ""
+        attrs.description = tool.Blender.get_blender_prop_default_value(attrs, "description")
+    else:
+        shape_aspect = tool.Ifc.get().by_id(int(shape_aspect_id))
+        attrs.name = shape_aspect.Name or ""
+        attrs.description = shape_aspect.Description or ""
 
 
 class RepresentationItem(PropertyGroup):

src/blenderbim/blenderbim/tool/geometry.py

@@ -299,6 +299,7 @@ class Geometry(blenderbim.core.tool.Geometry):
 
     @classmethod
     def get_active_representation(cls, obj):
+        """< IfcShapeRepresentation or None"""
         if obj.data and hasattr(obj.data, "BIMMeshProperties") and obj.data.BIMMeshProperties.ifc_definition_id:
             return tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
 
@@ -744,31 +745,56 @@ class Geometry(blenderbim.core.tool.Geometry):
         return shape_aspects
 
     @classmethod
-    def remove_representation_item_from_shape_aspect(cls, representation_item, shape_aspect):
+    def create_shape_aspect(cls, product_shape, base_representation, items, previous_shape_aspect=None):
+        """
+        > `product_shape` - IfcProductDefinitionShape or IfcRepresentationMap\n
+        > `base_representation` - base representation to get context attributes from\n
+        > `items` - representation items\n
+        > `previous_shape_aspect` - (optional) previous shape aspect, if provided\n
+        items will be removed the previous shape aspect first\n
+
+        < IfcShapeAspect
+        """
+
+        if previous_shape_aspect is not None:
+            cls.remove_representation_items_from_shape_aspect(items, previous_shape_aspect)
+
+        shape_aspect = tool.Ifc.get().createIfcShapeAspect(
+            PartOfProductDefinitionShape=product_shape, ShapeRepresentations=()
+        )
+        # keep IfcShapeAspect and IfcShapeRepresentation valid
+        rep = tool.Geometry.add_shape_aspect_representation(shape_aspect, base_representation)
+        rep.Items = items
+
+        return shape_aspect
+
+    @classmethod
+    def remove_representation_items_from_shape_aspect(cls, representation_items, shape_aspect):
         ifc_file = tool.Ifc.get()
         # as shape aspect might have multiple representations
         # it's easier to find it from the item
-        for inverse in ifc_file.get_inverse(representation_item):
+        for inverse in ifc_file.get_inverse(representation_items[0]):
             if inverse.is_a("IfcShapeRepresentation") and shape_aspect in inverse.OfShapeAspect:
                 representation = inverse
                 break
 
         # removing last item would make representation invalid
-        if len(representation.Items) == 1:
+        if len(representation.Items) == len(representation_items):
             # removing last representation would make shape aspect invalid.
             # remove shape aspect first otherwise remove_representation won't remove it because of the inverse
             if len(shape_aspect.ShapeRepresentations) == 1:
                 ifc_file.remove(shape_aspect)
             tool.Ifc.run("geometry.remove_representation", representation=representation)
         else:
-            items = set(representation.Items) - {representation_item}
+            items = set(representation.Items) - set(representation_items)
             representation.Items = tuple(items)
 
     @classmethod
-    def add_representation_item_to_shape_aspect(cls, representation_item, shape_aspect):
+    def add_representation_item_to_shape_aspect(cls, representation_items, shape_aspect):
+        """NOTE: we assume that all items belonged to the same representation and to the same shape aspect"""
         ifc_file = tool.Ifc.get()
         previous_shape_aspect = None
-        for inverse in ifc_file.get_inverse(representation_item):
+        for inverse in ifc_file.get_inverse(representation_items[0]):
             if inverse.is_a("IfcShapeRepresentation"):
                 if inverse.OfShapeAspect:
                     # item is already added to the shape aspect
@@ -780,11 +806,11 @@ class Geometry(blenderbim.core.tool.Geometry):
 
         # remove item from previous shape aspect
         if previous_shape_aspect:
-            cls.remove_representation_item_from_shape_aspect(representation_item, previous_shape_aspect)
+            cls.remove_representation_items_from_shape_aspect(representation_items, previous_shape_aspect)
         shape_aspect_representation = cls.get_shape_aspect_representation(
             shape_aspect, base_representation, create_new=True
         )
-        shape_aspect_representation.Items = shape_aspect_representation.Items + (representation_item,)
+        shape_aspect_representation.Items = shape_aspect_representation.Items + tuple(representation_items)
 
     @classmethod
     def get_shape_aspect_representation(cls, shape_aspect, base_representation, create_new=False):
@@ -799,11 +825,15 @@ class Geometry(blenderbim.core.tool.Geometry):
         if not create_new:
             return None
 
+        return cls.add_shape_aspect_representation(shape_aspect, base_representation)
+
+    @classmethod
+    def add_shape_aspect_representation(cls, shape_aspect, base_representation):
         shape_aspect_representation = tool.Ifc.get().createIfcShapeRepresentation(
             ContextOfItems=base_representation.ContextOfItems,
             RepresentationIdentifier=base_representation.RepresentationIdentifier,
             RepresentationType=base_representation.RepresentationType,
         )
         shape_aspect.ShapeRepresentations = shape_aspect.ShapeRepresentations + (shape_aspect_representation,)
-
         return shape_aspect_representation
+