Clever STAIR_ARROW annotation

Now adding STAIR_ARROW annotation is a bit more clever - if you have IfcStairFlight selected when adding this type of annotation it will automatically:
1) define stair as it's parent;
2) add the stair as it's product;
3) place itself along the stair (it's assumed that stair direction is X+)

Example - https://i.imgur.com/Ze9DoK2.png

src/blenderbim/blenderbim/bim/module/model/stair.py

@@ -286,6 +286,7 @@ def update_ifc_stair_props(obj):
         },
     )
     tool.Ifc.edit(obj)
+    # TODO: update related STAIR_ARROW products
 
 
 class BIM_OT_add_clever_stair(bpy.types.Operator, tool.Ifc.Operator):

src/blenderbim/blenderbim/core/drawing.py

@@ -232,6 +232,7 @@ def add_annotation(ifc, collector, drawing_tool, drawing=None, object_type=None)
         )
         ifc.run("group.assign_group", group=drawing_tool.get_drawing_group(drawing), products=[element])
     collector.assign(obj)
+    drawing_tool.setup_annotation_object(obj, object_type)
     drawing_tool.enable_editing(obj)
 
 

src/blenderbim/blenderbim/core/tool.py

@@ -71,16 +71,21 @@ class Aggregate:
 
 
 @interface
-class Blender: pass
-def create_ifc_object(cls, ifc_class, name, data): pass
-def get_name(cls, ifc_class, name): pass
-def get_obj_ifc_definition_id(cls, obj, obj_type): pass
-def get_selected_objects(cls): pass
-def set_active_object(cls, obj): pass
-def apply_bmesh(cls, mesh, bm): pass
-def get_bmesh_for_mesh(cls, mesh, clean=False): pass
-def get_viewport_context(cls): pass
-def update_viewport(cls): pass
+class Blender:
+    def set_active_object(cls, obj): pass
+    def get_name(cls, ifc_class, name): pass
+    def get_selected_objects(cls): pass
+    def create_ifc_object(cls, ifc_class: str, name: str = None, data=None): pass
+    def get_obj_ifc_definition_id(cls, obj=None, obj_type=None): pass
+    def is_ifc_object(cls, obj): pass
+    def is_ifc_class_active(cls, ifc_class): pass
+    def get_viewport_context(cls): pass
+    def update_viewport(cls): pass
+    def get_default_selection_keypmap(cls): pass
+    def get_object_bounding_box(cls, obj): pass
+    def apply_bmesh(cls, mesh, bm): pass
+    def get_bmesh_for_mesh(cls, mesh, clean=False): pass
+    def bmesh_join(cls, bm_a, bm_b, callback=None): pass
 
 
 @interface
@@ -223,6 +228,7 @@ class Drawing:
     def activate_view(cls, camera): pass
     def copy_representation(cls, source, dest): pass
     def create_annotation_object(cls, drawing, object_type): pass
+    def setup_annotation_object(cls, obj, object_type): pass
     def create_camera(cls, name, matrix): pass
     def create_svg_schedule(cls, schedule): pass
     def create_svg_sheet(cls, document, titleblock): pass

src/blenderbim/blenderbim/tool/blender.py

@@ -160,6 +160,24 @@ class Blender:
         )
         return keymap
 
+    @classmethod
+    def get_object_bounding_box(cls, obj):
+        """Returns dict with local min and max x, y, z values for the object.
+
+        Careful with using this method for objects in EDIT mode because
+        it requires all EDIT mode changes to be applied.
+        """
+        bound_box = obj.bound_box
+        bbox_dict = {
+            "min_x": bound_box[0][0],
+            "max_x": bound_box[6][0],
+            "min_y": bound_box[0][1],
+            "max_y": bound_box[6][1],
+            "min_z": bound_box[0][2],
+            "max_z": bound_box[6][2],
+        }
+        return bbox_dict
+
     ## BMESH UTILS ##
     @classmethod
     def apply_bmesh(cls, mesh, bm):

src/blenderbim/blenderbim/tool/drawing.py

@@ -38,6 +38,8 @@ import blenderbim.bim.module.drawing.helper as helper
 from blenderbim.bim.module.drawing.data import FONT_SIZES, DecoratorData
 from blenderbim.bim.module.drawing.prop import get_diagram_scales, BOX_ALIGNMENT_POSITIONS
 
+from mathutils import Vector
+
 
 class Drawing(blenderbim.core.tool.Drawing):
     @classmethod
@@ -74,8 +76,27 @@ class Drawing(blenderbim.core.tool.Drawing):
             obj = annotation.Annotator.add_line_to_annotation(obj, co2, co1)
         elif object_type != "TEXT":
             obj = annotation.Annotator.add_line_to_annotation(obj)
+
         return obj
 
+    @classmethod
+    def setup_annotation_object(cls, obj, object_type):
+        """Finish object's adjustments after both object and entity are created"""
+        if object_type == "STAIR_ARROW":
+            stair = bpy.context.active_object
+            stair_entity = tool.Ifc.get_entity(stair)
+            if stair_entity and stair_entity.is_a("IfcStairFlight"):
+                arrow = obj
+                arrow_element = tool.Ifc.get_entity(arrow)
+                arrow.parent = stair
+
+                # place the arrow
+                bbox = tool.Blender.get_object_bounding_box(stair)
+                arrow.location = Vector((bbox["min_x"], (bbox["max_y"] - bbox["min_y"]) / 2, bbox["max_z"]))
+                arrow.data.splines[0].points[1].co = Vector((bbox["max_x"], 0, 0, 1))
+
+                tool.Ifc.run("drawing.assign_product", relating_product=stair_entity, related_object=arrow_element)
+
     @classmethod
     def create_camera(cls, name, matrix):
         camera = bpy.data.objects.new(name, bpy.data.cameras.new(name))

src/blenderbim/test/core/test_drawing.py

@@ -321,6 +321,7 @@ class TestAddAnnotation:
         drawing.get_drawing_group("drawing").should_be_called().will_return("group")
         ifc.run("group.assign_group", group="group", products=["element"]).should_be_called()
         collector.assign("obj").should_be_called()
+        drawing.setup_annotation_object("obj", "object_type").should_be_called()
         drawing.enable_editing("obj").should_be_called()
         subject.add_annotation(ifc, collector, drawing, drawing="drawing", object_type="object_type")