Representation Items UI - support editing layers

Example - https://imgur.com/a/3fn051N

src/bonsai/bonsai/bim/module/geometry/__init__.py

@@ -34,6 +34,7 @@ classes = (
     operator.DuplicateMoveLinkedAggregate,
     operator.DuplicateMoveLinkedAggregateMacro,
     operator.EditObjectPlacement,
+    operator.EditRepresentationItemLayer,
     operator.EditRepresentationItemShapeAspect,
     operator.EditRepresentationItemStyle,
     operator.EnableEditingRepresentationItemShapeAspect,
@@ -67,6 +68,7 @@ classes = (
     operator.SelectConnection,
     operator.SelectRepresentationItem,
     operator.SwitchRepresentation,
+    operator.UnassignRepresentationItemLayer,
     operator.UnassignRepresentationItemStyle,
     operator.UpdateItemAttributes,
     operator.UpdateParametricRepresentation,

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

@@ -23,6 +23,7 @@ import logging
 import numpy as np
 import numpy.typing as npt
 import ifcopenshell
+import ifcopenshell.api.layer
 import ifcopenshell.util.element
 import ifcopenshell.util.placement
 import ifcopenshell.util.representation
@@ -2325,7 +2326,7 @@ class EnableEditingRepresentationItems(bpy.types.Operator, tool.Ifc.Operator):
     def _execute(self, context):
         obj = tool.Geometry.get_active_or_representation_obj()
 
-        props = obj.BIMGeometryProperties
+        props = tool.Geometry.get_object_geometry_props(obj)
         props.is_editing = True
 
         props.items.clear()
@@ -3209,3 +3210,51 @@ class OverrideMove(bpy.types.Operator):
             return {"FINISHED"}
 
         return {"FINISHED"}
+
+
+class EditRepresentationItemLayer(bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.edit_representation_item_layer"
+    bl_label = "Edit Representation Item Layer"
+    bl_description = "Edit presentation layer for the active representation item."
+    bl_options = {"REGISTER", "UNDO"}
+
+    def _execute(self, context):
+        ifc_file = tool.Ifc.get()
+        obj = context.active_object
+        assert obj
+        props = tool.Geometry.get_object_geometry_props(obj)
+        new_layer = ifc_file.by_id(int(props.representation_item_layer))
+
+        item = ifc_file.by_id(int(props.active_item.ifc_definition_id))
+        item_layer = next(iter(item.LayerAssignment), None)
+
+        # We assume just 1 layer can be assigned to representation item.
+        if item_layer:
+            # Same layer is already assigned.
+            if item_layer == new_layer:
+                props.is_editing_item_layer = False
+                return {"FINISHED"}
+            ifcopenshell.api.layer.unassign_layer(ifc_file, [item], item_layer)
+
+        ifcopenshell.api.layer.assign_layer(ifc_file, [item], new_layer)
+        props.is_editing_item_layer = False
+        bpy.ops.bim.enable_editing_representation_items()
+        return {"FINISHED"}
+
+
+class UnassignRepresentationItemLayer(bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.unassign_representation_item_layer"
+    bl_label = "Unassign Representation Item Layer"
+    bl_description = "Unassign presentation layer from the active representation item."
+    bl_options = {"REGISTER", "UNDO"}
+
+    def _execute(self, context):
+        ifc_file = tool.Ifc.get()
+        obj = context.active_object
+        assert obj
+        props = tool.Geometry.get_object_geometry_props(obj)
+        item = ifc_file.by_id(props.active_item.ifc_definition_id)
+        layer = item.LayerAssignment[0]  # If there is no layer, then button is not visible in UI.
+        ifcopenshell.api.layer.unassign_layer(ifc_file, [item], layer)
+        bpy.ops.bim.enable_editing_representation_items()
+        return {"FINISHED"}

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

@@ -32,7 +32,7 @@ from bpy.props import (
     FloatVectorProperty,
     CollectionProperty,
 )
-from typing import Optional
+from typing import Optional, TYPE_CHECKING
 
 
 def get_contexts(self, context):
@@ -105,6 +105,14 @@ def get_material_constituents(self, context, edit_text):
     return ObjectMaterialData.data["active_material_constituents"]
 
 
+def get_layers(self, context):
+    from bonsai.bim.module.layer.data import LayersData
+
+    if not LayersData.is_loaded:
+        LayersData.load()
+    return LayersData.data["layers_enum"]
+
+
 def update_shape_aspect(self, context):
     shape_aspect_id = self.representation_item_shape_aspect
     attrs = self.shape_aspect_attrs
@@ -128,6 +136,16 @@ class RepresentationItem(PropertyGroup):
     shape_aspect_id: IntProperty(name="Shape Aspect IFC ID")
     tags: StringProperty(name="Tags")
 
+    if TYPE_CHECKING:
+        name: str
+        surface_style: str
+        surface_style_id: int
+        layer: str
+        ifc_definition_id: int
+        shape_aspect: str
+        shape_aspect_id: int
+        tags: str
+
 
 class RepresentationItemObject(PropertyGroup):
     name: StringProperty(name="Name")
@@ -149,6 +167,20 @@ class ShapeAspect(PropertyGroup):
     )
 
 
+def update_is_editing_item_layer(self: "BIMObjectGeometryProperties", context: bpy.types.Context) -> None:
+    if self.is_editing_item_layer:
+        ifc_file = tool.Ifc.get()
+        active_ui_item = self.active_item
+        assert active_ui_item
+        item = ifc_file.by_id(active_ui_item.ifc_definition_id)
+        if layer := next(iter(item.LayerAssignment), None):
+            self.representation_item_layer = str(layer.id())
+        return
+
+    if "representation_item_layer" in self:
+        del self["representation_item_layer"]
+
+
 class BIMObjectGeometryProperties(PropertyGroup):
     contexts: EnumProperty(items=get_contexts, name="Contexts")
     is_editing: BoolProperty(name="Is Editing", default=False)
@@ -161,12 +193,32 @@ class BIMObjectGeometryProperties(PropertyGroup):
         items=get_shape_aspects, name="Representation Item Shape Aspect", update=update_shape_aspect
     )
     shape_aspect_attrs: PointerProperty(type=ShapeAspect)
+    is_editing_item_layer: BoolProperty(
+        name="Is Editing Item's Presentation Layer",
+        description="Toggle editing presentation layer for the item.",
+        default=False,
+        update=update_is_editing_item_layer,
+    )
+    representation_item_layer: EnumProperty(items=get_layers, name="Representation Item's Layer")
 
     @property
     def active_item(self):
-        if self.active_item_index < len(self.items):
+        if 0 <= self.active_item_index < len(self.items):
             return self.items[self.active_item_index]
 
+    if TYPE_CHECKING:
+        contexts: str
+        is_editing: bool
+        items: bpy.types.bpy_prop_collection_idprop[RepresentationItem]
+        active_item_index: int
+        is_editing_item_style: bool
+        representation_item_style: str
+        is_editing_item_shape_aspect: bool
+        representation_item_shape_aspect: str
+        shape_aspect_attrs: ShapeAspect
+        is_editing_item_layer: bool
+        representation_item_layer: str
+
 
 class BIMGeometryProperties(PropertyGroup):
     # Revit workaround

src/bonsai/bonsai/bim/module/geometry/ui.py

@@ -179,7 +179,7 @@ class BIM_PT_representation_items(Panel):
             RepresentationItemsData.load()
 
         obj = context.scene.BIMGeometryProperties.representation_obj or tool.Blender.get_active_object()
-        props = obj.BIMGeometryProperties
+        props = tool.Geometry.get_object_geometry_props(obj)
 
         row = self.layout.row(align=True)
         row.label(text=f"{RepresentationItemsData.data['total_items']} Items Found")
@@ -207,7 +207,9 @@ class BIM_PT_representation_items(Panel):
         surface_style = active_item.surface_style
         surface_style_id = active_item.surface_style_id
         shape_aspect = active_item.shape_aspect
+        layer = active_item.layer
 
+        # Style.
         row = self.layout.row(align=True)
         if props.is_editing_item_style:
             # NOTE: we currently support 1 item having just 1 style
@@ -226,9 +228,19 @@ class BIM_PT_representation_items(Panel):
             if surface_style:
                 row.operator("bim.unassign_representation_item_style", icon="X", text="")
 
-        row = self.layout.row()
-        row.label(text=active_item.layer or "No Presentation Layer", icon="STICKY_UVS_LOC")
+        # Presentation layer.
+        row = self.layout.row(align=True)
+        if props.is_editing_item_layer:
+            prop_with_search(row, props, "representation_item_layer", icon="STICKY_UVS_LOC", text="")
+            row.operator("bim.edit_representation_item_layer", icon="CHECKMARK", text="")
+            row.prop(props, "is_editing_item_layer", icon="CANCEL", text="")
+        else:
+            row.label(text=layer or "No Presentation Layer", icon="STICKY_UVS_LOC")
+            row.prop(props, "is_editing_item_layer", icon="GREASEPENCIL", text="")
+            if layer:
+                row.operator("bim.unassign_representation_item_layer", icon="X", text="")
 
+        # Mappings.
         if active_item.name.endswith("FaceSet"):
             if "UV" in active_item.tags:
                 text = "Has UV mapping"
@@ -242,6 +254,7 @@ class BIM_PT_representation_items(Panel):
                 text = "Has no colour mapping"
             self.layout.label(text=text, icon="COLOR")
 
+        # Shape aspect.
         row = self.layout.row(align=True)
         if props.is_editing_item_shape_aspect:
             row.prop(props, "representation_item_shape_aspect", icon="SHAPEKEY_DATA", text="")

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

@@ -19,6 +19,7 @@
 import bpy
 import ifcopenshell
 import bonsai.tool as tool
+from typing import Any
 
 
 def refresh():
@@ -31,12 +32,31 @@ class LayersData:
 
     @classmethod
     def load(cls):
-        cls.data = {"total_layers": cls.total_layers(), "active_layers": cls.active_layers()}
+        cls.data = {
+            "active_layers": cls.active_layers(),
+            "layers": cls.layers(),
+        }
+        # After .layers().
+        cls.data["total_layers"] = cls.total_layers()
+        cls.data["layers_enum"] = cls.layers_enum()
+
         cls.is_loaded = True
 
     @classmethod
     def total_layers(cls) -> int:
-        return len(tool.Ifc.get().by_type("IfcPresentationLayerAssignment"))
+        return len(cls.data["layers"])
+
+    @classmethod
+    def layers(cls) -> dict[int, dict[str, Any]]:
+        results = dict()
+        KEEP_ATTRS = set(("id", "Name", "Description"))
+        for layer in tool.Ifc.get().by_type("IfcPresentationLayerAssignment"):
+            results[layer.id()] = {k: v for k, v in layer.get_info().items() if k in KEEP_ATTRS}
+        return results
+
+    @classmethod
+    def layers_enum(cls) -> list[tuple[str, str, str]]:
+        return list((str(data["id"]), data["Name"], data["Description"] or "") for data in cls.data["layers"].values())
 
     @classmethod
     def active_layers(cls) -> dict[int, str]: