Fix #2611. Address multiple situations in the UI where the users could create invalid material data without an indication that it is invalid.

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

@@ -242,10 +242,11 @@ class RemoveConstituent(bpy.types.Operator, tool.Ifc.Operator):
     constituent: bpy.props.IntProperty()
 
     def _execute(self, context):
-        obj = bpy.data.objects.get(self.obj) if self.obj else context.active_object
-        self.file = IfcStore.get_file()
+        for inverse in tool.Ifc.get().get_inverse(layer):
+            if inverse.is_a("IfcMaterialConstituentSet") and len(inverse.MaterialConstituents) == 1:
+                return
         ifcopenshell.api.run(
-            "material.remove_constituent", self.file, **{"constituent": self.file.by_id(self.constituent)}
+            "material.remove_constituent", tool.Ifc.get(), constituent=tool.Ifc.get().by_id(self.constituent)
         )
 
 
@@ -276,9 +277,10 @@ class RemoveProfile(bpy.types.Operator, tool.Ifc.Operator):
     profile: bpy.props.IntProperty()
 
     def _execute(self, context):
-        obj = bpy.data.objects.get(self.obj) if self.obj else context.active_object
-        self.file = IfcStore.get_file()
-        ifcopenshell.api.run("material.remove_profile", self.file, **{"profile": self.file.by_id(self.profile)})
+        for inverse in tool.Ifc.get().get_inverse(layer):
+            if inverse.is_a("IfcMaterialProfileSet") and len(inverse.MaterialProfiles) == 1:
+                return
+        ifcopenshell.api.run("material.remove_profile", tool.Ifc.get(), profile=tool.Ifc.get().by_id(self.profile))
 
 
 class AddLayer(bpy.types.Operator, tool.Ifc.Operator):
@@ -333,9 +335,10 @@ class RemoveLayer(bpy.types.Operator, tool.Ifc.Operator):
     layer: bpy.props.IntProperty()
 
     def _execute(self, context):
-        obj = bpy.data.objects.get(self.obj) if self.obj else context.active_object
-        self.file = IfcStore.get_file()
-        ifcopenshell.api.run("material.remove_layer", self.file, **{"layer": self.file.by_id(self.layer)})
+        for inverse in tool.Ifc.get().get_inverse(layer):
+            if inverse.is_a("IfcMaterialLayerSet") and len(inverse.MaterialLayers) == 1:
+                return
+        ifcopenshell.api.run("material.remove_layer", tool.Ifc.get(), layer=tool.Ifc.get().by_id(self.layer))
 
 
 class AddListItem(bpy.types.Operator, tool.Ifc.Operator):

src/blenderbim/blenderbim/core/material.py

@@ -44,6 +44,8 @@ def add_material_set(ifc, material, set_type=None):
 
 
 def remove_material(ifc, material_tool, style, material=None):
+    if material_tool.is_material_used_in_sets(material):
+        return
     obj = ifc.get_object(material)
     ifc.unlink(element=material)
     ifc.run("material.remove_material", material=material)

src/blenderbim/blenderbim/core/tool.py

@@ -317,6 +317,7 @@ class Material:
     def get_name(cls, obj): pass
     def import_material_definitions(cls, material_type): pass
     def is_editing_materials(cls): pass
+    def is_material_used_in_sets(cls, material): pass
     def select_elements(cls, elements): pass
 
 

src/blenderbim/blenderbim/tool/material.py

@@ -89,6 +89,18 @@ class Material(blenderbim.core.tool.Material):
     def is_editing_materials(cls):
         return bpy.context.scene.BIMMaterialProperties.is_editing
 
+    @classmethod
+    def is_material_used_in_sets(cls, material):
+        for inverse in tool.Ifc.get().get_inverse(material):
+            if inverse.is_a() in [
+                "IfcMaterialProfile",
+                "IfcMaterialLayer",
+                "IfcMaterialConstituent",
+                "IfcMaterialList",
+            ]:
+                return True
+        return False
+
     @classmethod
     def select_elements(cls, elements):
         for element in elements:

src/blenderbim/test/core/test_material.py

@@ -94,6 +94,7 @@ class TestAddMaterialSet:
 
 class TestRemoveMaterial:
     def test_removing_a_material(self, ifc, material, style):
+        material.is_material_used_in_sets("material").should_be_called().will_return(False)
         ifc.get_object("material").should_be_called().will_return(None)
         ifc.unlink(element="material").should_be_called()
         ifc.run("material.remove_material", material="material").should_be_called()
@@ -101,6 +102,7 @@ class TestRemoveMaterial:
         subject.remove_material(ifc, material, style, material="material")
 
     def test_removing_a_material_and_reloading_imported_materials(self, ifc, material, style):
+        material.is_material_used_in_sets("material").should_be_called().will_return(False)
         ifc.get_object("material").should_be_called().will_return(None)
         ifc.unlink(element="material").should_be_called()
         ifc.run("material.remove_material", material="material").should_be_called()
@@ -110,6 +112,7 @@ class TestRemoveMaterial:
         subject.remove_material(ifc, material, style, material="material")
 
     def test_removing_a_material_object_if_it_has_no_style(self, ifc, material, style):
+        material.is_material_used_in_sets("material").should_be_called().will_return(False)
         ifc.get_object("material").should_be_called().will_return("obj")
         ifc.unlink(element="material").should_be_called()
         ifc.run("material.remove_material", material="material").should_be_called()
@@ -119,6 +122,7 @@ class TestRemoveMaterial:
         subject.remove_material(ifc, material, style, material="material")
 
     def test_preserving_a_material_object_if_it_is_still_used_as_a_style(self, ifc, material, style):
+        material.is_material_used_in_sets("material").should_be_called().will_return(False)
         ifc.get_object("material").should_be_called().will_return("obj")
         ifc.unlink(element="material").should_be_called()
         ifc.run("material.remove_material", material="material").should_be_called()
@@ -126,6 +130,10 @@ class TestRemoveMaterial:
         material.is_editing_materials().should_be_called().will_return(False)
         subject.remove_material(ifc, material, style, material="material")
 
+    def test_not_removing_a_material_if_it_is_used_in_a_material_set(self, ifc, material, style):
+        material.is_material_used_in_sets("material").should_be_called().will_return(True)
+        subject.remove_material(ifc, material, style, material="material")
+
 
 class TestRemoveMaterialSet:
     def test_run(self, ifc, material):

src/blenderbim/test/tool/test_material.py

@@ -153,9 +153,22 @@ class TestImportMaterialDefinitions(NewFile):
 class TestIsEditingMaterials(NewFile):
     def test_run(self):
         bpy.context.scene.BIMMaterialProperties.is_editing = False
-        subject.is_editing_materials() is False
+        assert subject.is_editing_materials() is False
         bpy.context.scene.BIMMaterialProperties.is_editing = True
-        subject.is_editing_materials() is True
+        assert subject.is_editing_materials() is True
+
+
+class TestIsMaterialUsedInSets(NewFile):
+    def test_run(self):
+        ifc = ifcopenshell.file()
+        tool.Ifc.set(ifc)
+        material_set = ifc.createIfcMaterialLayerSet()
+        material_set_item = ifc.createIfcMaterialLayer()
+        material = ifc.createIfcMaterial()
+        assert subject.is_material_used_in_sets(material) is False
+        material_set.MaterialLayers = [material_set_item]
+        material_set_item.Material = material
+        assert subject.is_material_used_in_sets(material) is True
 
 
 class TestSelectElements(NewFile):