Support editing representation's presentation layers from UI

Example - https://imgur.com/a/QgtSUoq

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

@@ -26,6 +26,7 @@ classes = (
     operator.AddMeshlikeItem,
     operator.AddRepresentation,
     operator.AddSweptAreaSolidItem,
+    operator.AssignRepresentationLayer,
     operator.CopyRepresentation,
     operator.DisableEditingRepresentationItemShapeAspect,
     operator.DisableEditingRepresentationItemStyle,
@@ -70,6 +71,7 @@ classes = (
     operator.SwitchRepresentation,
     operator.UnassignRepresentationItemLayer,
     operator.UnassignRepresentationItemStyle,
+    operator.UnassignRepresentationLayer,
     operator.UpdateItemAttributes,
     operator.UpdateParametricRepresentation,
     operator.UpdateRepresentation,

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

@@ -3259,3 +3259,52 @@ class UnassignRepresentationItemLayer(bpy.types.Operator, tool.Ifc.Operator):
         ifcopenshell.api.layer.unassign_layer(ifc_file, [item], layer)
         bpy.ops.bim.enable_editing_representation_items()
         return {"FINISHED"}
+
+
+class AssignRepresentationLayer(bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.assign_representation_layer"
+    bl_label = "Assign Representation Layer"
+    bl_description = "Assign presentation layer to the active representation."
+    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_layer))
+
+        representation = tool.Geometry.get_active_representation(obj)
+        assert representation
+        item_layers = representation.LayerAssignments
+
+        # On practice enum doesn't display already assigned layers
+        # but let's double check.
+        if new_layer in item_layers:
+            props.is_adding_representation_layer = False
+            return {"FINISHED"}
+
+        ifcopenshell.api.layer.assign_layer(ifc_file, [representation], new_layer)
+        props.is_adding_representation_layer = False
+        return {"FINISHED"}
+
+
+class UnassignRepresentationLayer(bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.unassign_representation_layer"
+    bl_label = "Unassign Representation Layer"
+    bl_description = "Unassign presentation layer from the active representation."
+    bl_options = {"REGISTER", "UNDO"}
+
+    layer_id: bpy.props.IntProperty()
+
+    def _execute(self, context):
+        ifc_file = tool.Ifc.get()
+        obj = context.active_object
+        assert obj
+
+        representation = tool.Geometry.get_active_representation(obj)
+        assert representation
+
+        layer = ifc_file.by_id(self.layer_id)
+        ifcopenshell.api.layer.unassign_layer(ifc_file, [representation], layer)
+        return {"FINISHED"}

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

@@ -113,6 +113,14 @@ def get_layers(self, context):
     return LayersData.data["layers_enum"]
 
 
+def get_layers_no_active(self, context):
+    from bonsai.bim.module.layer.data import LayersData
+
+    if not LayersData.is_loaded:
+        LayersData.load()
+    return LayersData.data["layers_enum_no_active"]
+
+
 def update_shape_aspect(self, context):
     shape_aspect_id = self.representation_item_shape_aspect
     attrs = self.shape_aspect_attrs
@@ -169,6 +177,15 @@ class ShapeAspect(PropertyGroup):
     )
 
 
+def update_is_editing_representation_layer(self: "BIMObjectGeometryProperties", context: bpy.types.Context) -> None:
+    if self.is_adding_representation_layer:
+        return
+
+    if "representation_layer" in self:
+        del self["representation_layer"]
+        del self["is_adding_representation_layer"]
+
+
 def update_is_editing_item_layer(self: "BIMObjectGeometryProperties", context: bpy.types.Context) -> None:
     if self.is_editing_item_layer:
         ifc_file = tool.Ifc.get()
@@ -181,10 +198,25 @@ def update_is_editing_item_layer(self: "BIMObjectGeometryProperties", context: b
 
     if "representation_item_layer" in self:
         del self["representation_item_layer"]
+        del self["is_editing_item_layer"]
 
 
 class BIMObjectGeometryProperties(PropertyGroup):
+    # Representations UI.
     contexts: EnumProperty(items=get_contexts, name="Contexts")
+    is_adding_representation_layer: BoolProperty(
+        name="Is Adding Representation's Layer",
+        description="Toggle adding presentation layer for the representation.",
+        default=False,
+    )
+    representation_layer: EnumProperty(
+        items=get_layers_no_active,
+        name="Representation's Presentation Layer",
+        description="Presentation layer to add.",
+        update=update_is_editing_representation_layer,
+    )
+
+    # Representation items UI.
     is_editing: BoolProperty(name="Is Editing", default=False)
     items: CollectionProperty(name="Representation Items", type=RepresentationItem)
     active_item_index: IntProperty(name="Active Representation Item Index")
@@ -210,6 +242,8 @@ class BIMObjectGeometryProperties(PropertyGroup):
 
     if TYPE_CHECKING:
         contexts: str
+        is_adding_representation_layer: bool
+        representation_layer: str
         is_editing: bool
         items: bpy.types.bpy_prop_collection_idprop[RepresentationItem]
         active_item_index: int

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

@@ -122,11 +122,16 @@ class BIM_PT_representations(Panel):
         return tool.Ifc.get() and (obj := tool.Blender.get_active_object()) and tool.Ifc.get_entity(obj)
 
     def draw(self, context):
+        layout = self.layout
         if not RepresentationsData.is_loaded:
             RepresentationsData.load()
 
+        obj = context.active_object
+        assert obj
+        props = tool.Geometry.get_object_geometry_props(obj)
+
         row = self.layout.row(align=True)
-        prop_with_search(row, context.active_object.BIMGeometryProperties, "contexts", text="")
+        prop_with_search(row, props, "contexts", text="")
         row.operator("bim.add_representation", icon="ADD", text="")
 
         if not RepresentationsData.data["representations"]:
@@ -150,15 +155,38 @@ class BIM_PT_representations(Panel):
             op.disable_opening_subtractions = False
             row.operator("bim.remove_representation", icon="X", text="").representation_id = representation["id"]
 
+        # Presentation layers.
         self.layout.separator()
         if not LayersData.is_loaded:
             LayersData.load()
-        if LayersData.data["active_layers"]:
-            self.layout.label(text="Representation Presentation Layers:")
-            for layer_name in LayersData.data["active_layers"].values():
-                self.layout.label(text=layer_name, icon="STICKY_UVS_LOC")
+
+        if active_layers := LayersData.data["active_layers"]:
+            row = layout.row(align=True)
+            row.label(text="Representation Presentation Layers:")
+            if props.is_adding_representation_layer:
+                row = layout.row(align=True)
+                row.prop(props, "representation_layer", text="")
+                op = row.operator("bim.assign_representation_layer", icon="CHECKMARK", text="")
+                row.prop(props, "is_adding_representation_layer", icon="CANCEL", text="")
+            else:
+                row.prop(props, "is_adding_representation_layer", icon="ADD", text="")
+
+            for layer_id, layer_name in active_layers.items():
+                row = layout.row(align=True)
+                row.label(text=layer_name, icon="STICKY_UVS_LOC")
+                op = row.operator("bim.layer_ui_select", icon="ZOOM_SELECTED", text="")
+                op.layer_id = layer_id
+                op = row.operator("bim.unassign_representation_layer", icon="X", text="")
+                op.layer_id = layer_id
         else:
-            self.layout.label(text="Representation Has No Presentation Layers", icon="STICKY_UVS_LOC")
+            row = layout.row(align=True)
+            if props.is_adding_representation_layer:
+                row.prop(props, "representation_layer", text="")
+                op = row.operator("bim.assign_representation_layer", icon="CHECKMARK", text="")
+                row.prop(props, "is_adding_representation_layer", icon="CANCEL", text="")
+            else:
+                row.label(text="Representation Has No Presentation Layers", icon="STICKY_UVS_LOC")
+                row.prop(props, "is_adding_representation_layer", icon="GREASEPENCIL", text="")
 
 
 class BIM_PT_representation_items(Panel):

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

@@ -38,7 +38,9 @@ class LayersData:
         }
         # After .layers().
         cls.data["total_layers"] = cls.total_layers()
+        # After .layers() and .active_layers().
         cls.data["layers_enum"] = cls.layers_enum()
+        cls.data["layers_enum_no_active"] = cls.layers_enum(skip_active=True)
 
         cls.is_loaded = True
 
@@ -55,8 +57,13 @@ class LayersData:
         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())
+    def layers_enum(cls, skip_active: bool = False) -> list[tuple[str, str, str]]:
+        active_layers = cls.data["active_layers"]
+        return list(
+            (str(data["id"]), data["Name"], data["Description"] or "")
+            for data in cls.data["layers"].values()
+            if not skip_active or (data["id"] not in active_layers)
+        )
 
     @classmethod
     def active_layers(cls) -> dict[int, str]:
@@ -71,4 +78,4 @@ class LayersData:
             attr_name = "LayerAssignment"
         if attr_name is None:
             return results
-        return {layer.id(): layer.Name for layer in getattr(shape, attr_name)}
+        return {layer.id(): layer.Name or "Unnamed" for layer in getattr(shape, attr_name)}