remove bbim material unassignment listener #4843

Listeners are implicit and get in the way sometimes, we should work on our core methods and make explicit calls.

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

@@ -406,7 +406,9 @@ class UpdateRepresentation(bpy.types.Operator, Operator):
                 element_type = ifcopenshell.util.element.get_type(product)
                 if element_type:  # Some invalid IFCs use material sets without a type.
                     ifcopenshell.api.run("material.unassign_material", tool.Ifc.get(), products=[element_type])
+                    tool.Material.ensure_material_unassigned([element_type])
                 ifcopenshell.api.run("material.unassign_material", tool.Ifc.get(), products=[product])
+                tool.Material.ensure_material_unassigned([product])
             else:
                 # These objects are parametrically based on an axis and should not be modified as a mesh
                 return

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

@@ -50,10 +50,6 @@ def load_post(*args):
             usecase, "BlenderBIM.Product.EnsureMaterialAssigned", product.ensure_material_assigned
         )
 
-    ifcopenshell.api.add_post_listener(
-        "material.unassign_material", "BlenderBIM.Product.EnsureMaterialUnassigned", product.ensure_material_unassigned
-    )
-
     ifcopenshell.api.add_post_listener(
         "material.edit_profile_usage",
         "BlenderBIM.Product.RegenerateProfileUsage",

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

@@ -542,23 +542,3 @@ def ensure_material_assigned(usecase_path: str, ifc_file: ifcopenshell.file, set
             elements.extend(tool.Model.get_occurrences_without_material_override(element))
 
     tool.Model.apply_ifc_material_changes(elements, assigned_material=settings["material"])
-
-
-def ensure_material_unassigned(usecase_path: str, ifc_file: ifcopenshell.file, settings: dict[str, Any]) -> None:
-    return  # TODO ensure this now works with the new approach of styles
-    elements = settings["products"]
-
-    # unassign_material could be called when product is about to get removed
-    # and representation might be already removed.
-    elements = [
-        e
-        for e in elements
-        if (obj := tool.Ifc.get_object(e))
-        and obj.data
-        and tool.Ifc.get_entity_by_id(obj.data.BIMMeshProperties.ifc_definition_id)
-    ]
-
-    for element in elements[:]:
-        if element.is_a("IfcElementType"):
-            elements.extend(tool.Model.get_occurrences_without_material_override(element))
-    tool.Model.apply_ifc_material_changes(elements)

src/blenderbim/blenderbim/core/material.py

@@ -116,21 +116,27 @@ def assign_material(
 def unassign_material(ifc: tool.Ifc, material_tool: tool.Material, objects: list[bpy.types.Object]) -> None:
     for obj in objects:
         element = ifc.get_entity(obj)
-        if element:
+        if not element:
-            material = material_tool.get_material(element, should_inherit=False)
+            continue
-            inherited_material = material_tool.get_material(element, should_inherit=True)
+        material = material_tool.get_material(element, should_inherit=False)
-            if material:
+        inherited_material = material_tool.get_material(element, should_inherit=True)
-                if "Usage" in material.is_a():
+        if material:
-                    element_type = material_tool.get_type(element)
+            if "Usage" in material.is_a():
-                    ifc.run("material.unassign_material", products=[element_type])
-                else:
-                    ifc.run("material.unassign_material", products=[element])
-            elif inherited_material:
                 element_type = material_tool.get_type(element)
+                assert element_type  # Type checker.
                 ifc.run("material.unassign_material", products=[element_type])
+                material_tool.ensure_material_unassigned(elements=[element_type])
             else:
-                # Has no material and has no inherited material, nothing to unassign.
+                ifc.run("material.unassign_material", products=[element])
-                pass
+                material_tool.ensure_material_unassigned(elements=[element])
+        elif inherited_material:
+            element_type = material_tool.get_type(element)
+            assert element_type  # Type checker.
+            ifc.run("material.unassign_material", products=[element_type])
+            material_tool.ensure_material_unassigned(elements=[element_type])
+        else:
+            # Has no material and has no inherited material, nothing to unassign.
+            pass
 
 
 def patch_non_parametric_mep_segment(

src/blenderbim/blenderbim/tool/material.py

@@ -284,3 +284,18 @@ class Material(blenderbim.core.tool.Material):
                     for style in item.Styles:
                         if style.is_a("IfcSurfaceStyle"):
                             return style
+
+    @classmethod
+    def ensure_material_unassigned(cls, elements: list[ifcopenshell.entity_instance]) -> None:
+        """Ensure blender materials are updated after a material unassignment.
+
+        E.g. during a material unassignment some material style may not apply anymore
+        or some other may be applied now since it's no longer overridden,
+        therefore we need to make sure blender materials reflect correct styles.
+
+        Designed to be called after material.unassign_material API call."""
+        elements = elements.copy()  # Avoid argument mutation.
+        for element in elements[:]:
+            if element.is_a("IfcElementType"):
+                elements.extend(tool.Model.get_occurrences_without_material_override(element))
+        tool.Model.apply_ifc_material_changes(elements)

src/blenderbim/test/tool/test_model.py

@@ -546,6 +546,7 @@ class TestApplyIfcMaterialChanges(NewFile):
             assert self.get_used_styles(obj) == expected
 
         ifcopenshell.api.material.unassign_material(ifc_file, products=[element_type])
+        tool.Material.ensure_material_unassigned([element_type])
         assert self.get_used_styles(tool.Ifc.get_object(element_type)) == set()
         for element in ifc_file.by_type("IfcActuator"):
             obj = tool.Ifc.get_object(element)
@@ -573,6 +574,7 @@ class TestApplyIfcMaterialChanges(NewFile):
             assert self.get_used_styles(obj) == {green_style}
 
         ifcopenshell.api.material.unassign_material(ifc_file, products=[element_type])
+        tool.Material.ensure_material_unassigned([element_type])
         assert self.get_used_styles(tool.Ifc.get_object(element_type)) == {green_style}
         for element in ifc_file.by_type("IfcActuator"):
             obj = tool.Ifc.get_object(element)
@@ -613,6 +615,7 @@ class TestApplyIfcMaterialChanges(NewFile):
         ifcopenshell.api.material.assign_material(ifc_file, products=[element], material=red_material)
         assert self.get_used_styles(obj) == {green_style, red_style}
         ifcopenshell.api.material.unassign_material(ifc_file, products=[element])
+        tool.Material.ensure_material_unassigned([element])
         mesh = self.get_mesh(obj)
         assert len(mesh.materials) == 2
         assert set(mesh.materials) == {bpy.data.materials["Green"], None}
@@ -630,6 +633,7 @@ class TestApplyIfcMaterialChanges(NewFile):
         assert set(get_material_indices(mesh)) == {mesh.materials.find("Red")}
 
         ifcopenshell.api.material.unassign_material(ifc_file, products=[element])
+        tool.Material.ensure_material_unassigned([element])
         mesh = self.get_mesh(obj)
         assert len(mesh.materials) == 2
         assert set(mesh.materials) == {bpy.data.materials["Red"], None}
@@ -651,4 +655,5 @@ class TestApplyIfcMaterialChanges(NewFile):
         assert self.get_mesh(obj).materials[:] == []
 
         ifcopenshell.api.material.unassign_material(ifc_file, products=[element])
+        tool.Material.ensure_material_unassigned([element])
         assert self.get_mesh(obj).materials[:] == [bpy.data.materials["Red"]]