You can now assign and unassign styles to materials

src/ifcopenshell-python/ifcopenshell/api/style/remove_styled_representation.py

@@ -0,0 +1,54 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2023 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+
+class Usecase:
+    def __init__(self, file, representation=None):
+        """Removes a styled representation
+
+        Styled representations are typically associated with materials. This
+        removes the representation but not the underlying styles.
+
+        :param representation: The IfcStyledRepresentation to remove.
+        :type representation: ifcopenshell.entity_instance.entity_instance
+        :return: None
+        :rtype: None
+
+        Example:
+
+        .. code:: python
+
+            # Remove a styled representation
+            ifcopenshell.api.run("style.remove_styled_representation", model, representation=representation)
+        """
+        self.file = file
+        self.settings = {"representation": representation}
+
+    def execute(self):
+        for inverse in self.file.get_inverse(self.settings["representation"]):
+            if inverse.is_a("IfcMaterialDefinitionRepresentation") and len(inverse.Representations) == 1:
+                self.file.remove(inverse)
+
+        for item in self.settings["representation"].Items:
+            if item.is_a("IfcStyledItem") and self.file.get_total_inverses(item) == 1:
+                for style in item.Styles:
+                    if style.is_a("IfcPresentationStyleAssignment"):
+                        self.file.remove(style)
+                self.file.remove(item)
+
+        self.file.remove(self.settings["representation"])

src/ifcopenshell-python/ifcopenshell/api/style/unassign_material_style.py

@@ -0,0 +1,70 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2023 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+
+class Usecase:
+    def __init__(self, file, material=None, style=None, context=None):
+        """Unassigns a style to a material
+
+        This does the inverse of assign_material_style.
+
+        :param material: The IfcMaterial which you want to unassign the style from.
+        :type material: ifcopenshell.entity_instance.entity_instance
+        :param style: The IfcPresentationStyle (typically IfcSurfaceStyle) that
+            you want to unassign from material. This will then be applied to all
+            objects that have that material.
+        :type style: ifcopenshell.entity_instance.entity_instance
+        :param context: The IfcGeometricRepresentationSubContext at which this
+            style should be unassigned. Typically this is the Model BODY context.
+        :type context: ifcopenshell.entity_instance.entity_instance
+        :return: None
+        :rtype: None
+
+        Example:
+
+        .. code:: python
+
+            ifcopenshell.api.run("style.unassign_material_style", model, material=concrete, style=style, context=body)
+        """
+        self.file = file
+        self.settings = {
+            "material": material,
+            "style": style,
+            "context": context,
+        }
+
+    def execute(self):
+        to_delete = set()
+        for definition in self.settings["material"].HasRepresentation:
+            for representation in definition.Representations:
+                if not representation.is_a("IfcStyledRepresentation"):
+                    continue
+                if representation.ContextOfItems != self.settings["context"]:
+                    continue
+                for item in representation.Items:
+                    if not item.is_a("IfcStyledItem"):
+                        continue
+                    styles = [s for s in item.Styles if s != self.settings["style"]]
+                    if not styles:
+                        self.file.remove(item)
+                    elif len(styles) != len(item.Styles):
+                        item.Styles = styles
+                if not representation.Items:
+                    self.file.remove(representation)
+            if not definition.Representations:
+                self.file.remove(definition)