Fix #1546. New feature to copy the material of the active object to selected objects.

src/ifcopenshell-python/ifcopenshell/api/material/add_material.py

@@ -1,6 +1,3 @@
-import ifcopenshell
-
-
 class Usecase:
     def __init__(self, file, **settings):
         self.file = file

src/ifcopenshell-python/ifcopenshell/api/material/copy_material.py

@@ -0,0 +1,30 @@
+import ifcopenshell
+import ifcopenshell.util.element
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"material": None, "element": None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        ifcopenshell.api.run("material.unassign_material", self.file, product=self.settings["element"])
+        if self.settings["material"].is_a("IfcMaterial"):
+            ifcopenshell.api.run(
+                "material.assign_material",
+                self.file,
+                product=self.settings["element"],
+                type="IfcMaterial",
+                material=self.settings["material"],
+            )
+        # No other material type can be copied right now.
+        # 1. Material lists and constituents may have shape aspects and I
+        # haven't implemented it yet.
+        # 2. Material layer and profile sets implicitly define parametric
+        # geometry and we have no way of guaranteeing that this constraint is
+        # satisfied.
+        # 3. Material set usages follow an unofficial constraint that all
+        # instances must have a usage of their type's material set. We cannot
+        # guarantee that constraint.