Move towards making extruder manager a first class citizen - CURA-4482

cura/BuildVolume.py

@@ -917,24 +917,23 @@ class BuildVolume(SceneNode):
     #   which extruder to get the setting, if there are multiple extruders.
     #   \param property The property to get from the setting.
     #   \return The property of the specified setting in the specified extruder.
-    def _getSettingFromExtruder(self, setting_key, extruder_setting_key, property = "value"):
-        multi_extrusion = self._global_container_stack.getProperty("machine_extruder_count", "value") > 1
+    def _getSettingFromExtruder(self, setting_key, extruder_setting_key, prop = "value"):
+        extruder_index = self._global_container_stack.getProperty(extruder_setting_key, "value")
 
-        if not multi_extrusion:
-            stack = self._global_container_stack
+        # TODO: remove this - CURA-4482
+        if str(extruder_index) == "-1":  # If extruder index is -1 use global instead
+            extruder_stack = self._global_container_stack
         else:
-            extruder_index = self._global_container_stack.getProperty(extruder_setting_key, "value")
+            extruder_stack_id = ExtruderManager.getInstance().extruderIds[str(extruder_index)]
+            extruder_stack = ContainerRegistry.getInstance().findContainerStacks(id = extruder_stack_id)[0]
 
-            if str(extruder_index) == "-1":  # If extruder index is -1 use global instead
-                stack = self._global_container_stack
-            else:
-                extruder_stack_id = ExtruderManager.getInstance().extruderIds[str(extruder_index)]
-                stack = ContainerRegistry.getInstance().findContainerStacks(id = extruder_stack_id)[0]
+        value = extruder_stack.getProperty(setting_key, prop)
+        setting_type = extruder_stack.getProperty(setting_key, "type")
 
-        value = stack.getProperty(setting_key, property)
-        setting_type = stack.getProperty(setting_key, "type")
+        # default 0 for numerical values
         if not value and (setting_type == "int" or setting_type == "float"):
             return 0
+
         return value
 
     ##  Convenience function to calculate the disallowed radius around the edge.
@@ -945,6 +944,7 @@ class BuildVolume(SceneNode):
     def _getEdgeDisallowedSize(self):
         if not self._global_container_stack:
             return 0
+
         container_stack = self._global_container_stack
         used_extruders = ExtruderManager.getInstance().getUsedExtruderStacks()
 
@@ -953,26 +953,33 @@ class BuildVolume(SceneNode):
             return 0.1  # Return a very small value, so we do draw disallowed area's near the edges.
 
         adhesion_type = container_stack.getProperty("adhesion_type", "value")
+
         if adhesion_type == "skirt":
             skirt_distance = self._getSettingFromAdhesionExtruder("skirt_gap")
             skirt_line_count = self._getSettingFromAdhesionExtruder("skirt_line_count")
             bed_adhesion_size = skirt_distance + (self._getSettingFromAdhesionExtruder("skirt_brim_line_width") * skirt_line_count) * self._getSettingFromAdhesionExtruder("initial_layer_line_width_factor") / 100.0
-            if len(used_extruders) > 1:
-                for extruder_stack in used_extruders:
-                    bed_adhesion_size += extruder_stack.getProperty("skirt_brim_line_width", "value") * extruder_stack.getProperty("initial_layer_line_width_factor", "value") / 100.0
-                #We don't create an additional line for the extruder we're printing the skirt with.
-                bed_adhesion_size -= self._getSettingFromAdhesionExtruder("skirt_brim_line_width", "value") * self._getSettingFromAdhesionExtruder("initial_layer_line_width_factor", "value") / 100.0
+
+            for extruder_stack in used_extruders:
+                bed_adhesion_size += extruder_stack.getProperty("skirt_brim_line_width", "value") * extruder_stack.getProperty("initial_layer_line_width_factor", "value") / 100.0
+
+            # We don't create an additional line for the extruder we're printing the skirt with.
+            bed_adhesion_size -= self._getSettingFromAdhesionExtruder("skirt_brim_line_width", "value") * self._getSettingFromAdhesionExtruder("initial_layer_line_width_factor", "value") / 100.0
+
         elif adhesion_type == "brim":
             bed_adhesion_size = self._getSettingFromAdhesionExtruder("skirt_brim_line_width") * self._getSettingFromAdhesionExtruder("brim_line_count") *  self._getSettingFromAdhesionExtruder("initial_layer_line_width_factor") / 100.0
-            if self._global_container_stack.getProperty("machine_extruder_count", "value") > 1:
-                for extruder_stack in used_extruders:
-                    bed_adhesion_size += extruder_stack.getProperty("skirt_brim_line_width", "value") * extruder_stack.getProperty("initial_layer_line_width_factor", "value") / 100.0
-                #We don't create an additional line for the extruder we're printing the brim with.
-                bed_adhesion_size -= self._getSettingFromAdhesionExtruder("skirt_brim_line_width", "value") * self._getSettingFromAdhesionExtruder("initial_layer_line_width_factor", "value") / 100.0
+
+            for extruder_stack in used_extruders:
+                bed_adhesion_size += extruder_stack.getProperty("skirt_brim_line_width", "value") * extruder_stack.getProperty("initial_layer_line_width_factor", "value") / 100.0
+
+            # We don't create an additional line for the extruder we're printing the brim with.
+            bed_adhesion_size -= self._getSettingFromAdhesionExtruder("skirt_brim_line_width", "value") * self._getSettingFromAdhesionExtruder("initial_layer_line_width_factor", "value") / 100.0
+
         elif adhesion_type == "raft":
             bed_adhesion_size = self._getSettingFromAdhesionExtruder("raft_margin")
+
         elif adhesion_type == "none":
             bed_adhesion_size = 0
+
         else:
             raise Exception("Unknown bed adhesion type. Did you forget to update the build volume calculations for your new bed adhesion type?")
 

cura/ConvexHullDecorator.py

@@ -302,24 +302,23 @@ class ConvexHullDecorator(SceneNodeDecorator):
             self._onChanged()
 
     ##   Private convenience function to get a setting from the correct extruder (as defined by limit_to_extruder property).
-    def _getSettingProperty(self, setting_key, property = "value"):
+    def _getSettingProperty(self, setting_key, prop = "value"):
         per_mesh_stack = self._node.callDecoration("getStack")
         if per_mesh_stack:
-            return per_mesh_stack.getProperty(setting_key, property)
-
-        multi_extrusion = self._global_stack.getProperty("machine_extruder_count", "value") > 1
-        if not multi_extrusion:
-            return self._global_stack.getProperty(setting_key, property)
+            return per_mesh_stack.getProperty(setting_key, prop)
 
         extruder_index = self._global_stack.getProperty(setting_key, "limit_to_extruder")
-        if extruder_index == "-1": #No limit_to_extruder.
+        if extruder_index == "-1":
+            # No limit_to_extruder
             extruder_stack_id = self._node.callDecoration("getActiveExtruder")
-            if not extruder_stack_id: #Decoration doesn't exist.
+            if not extruder_stack_id:
+                # Decoration doesn't exist
                 extruder_stack_id = ExtruderManager.getInstance().extruderIds["0"]
             extruder_stack = ContainerRegistry.getInstance().findContainerStacks(id = extruder_stack_id)[0]
-            return extruder_stack.getProperty(setting_key, property)
-        else: #Limit_to_extruder is set. The global stack handles this then.
-            return self._global_stack.getProperty(setting_key, property)
+            return extruder_stack.getProperty(setting_key, prop)
+        else:
+            # Limit_to_extruder is set. The global stack handles this then
+            return self._global_stack.getProperty(setting_key, prop)
 
     ## Returns true if node is a descendant or the same as the root node.
     def __isDescendant(self, root, node):

cura/CuraApplication.py

@@ -200,6 +200,7 @@ class CuraApplication(QtApplication):
 
         self._machine_action_manager = MachineActionManager.MachineActionManager()
         self._machine_manager = None    # This is initialized on demand.
+        self._extruder_manager = None
         self._material_manager = None
         self._setting_inheritance_manager = None
         self._simple_mode_settings_manager = None
@@ -259,20 +260,24 @@ class CuraApplication(QtApplication):
         # Since they are empty, they should never be serialized and instead just programmatically created.
         # We need them to simplify the switching between materials.
         empty_container = ContainerRegistry.getInstance().getEmptyInstanceContainer()
+
         empty_variant_container = copy.deepcopy(empty_container)
         empty_variant_container._id = "empty_variant"
         empty_variant_container.addMetaDataEntry("type", "variant")
         ContainerRegistry.getInstance().addContainer(empty_variant_container)
+
         empty_material_container = copy.deepcopy(empty_container)
         empty_material_container._id = "empty_material"
         empty_material_container.addMetaDataEntry("type", "material")
         ContainerRegistry.getInstance().addContainer(empty_material_container)
+
         empty_quality_container = copy.deepcopy(empty_container)
         empty_quality_container._id = "empty_quality"
         empty_quality_container.setName("Not Supported")
         empty_quality_container.addMetaDataEntry("quality_type", "normal")
         empty_quality_container.addMetaDataEntry("type", "quality")
         ContainerRegistry.getInstance().addContainer(empty_quality_container)
+
         empty_quality_changes_container = copy.deepcopy(empty_container)
         empty_quality_changes_container._id = "empty_quality_changes"
         empty_quality_changes_container.addMetaDataEntry("type", "quality_changes")
@@ -413,7 +418,7 @@ class CuraApplication(QtApplication):
     def discardOrKeepProfileChangesClosed(self, option):
         if option == "discard":
             global_stack = self.getGlobalContainerStack()
-            for extruder in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+            for extruder in self._extruder_manager.getMachineExtruders(global_stack.getId()):
                 extruder.getTop().clear()
             global_stack.getTop().clear()
 
@@ -421,7 +426,7 @@ class CuraApplication(QtApplication):
         # before slicing. To ensure that slicer uses right settings values
         elif option == "keep":
             global_stack = self.getGlobalContainerStack()
-            for extruder in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+            for extruder in self._extruder_manager.getMachineExtruders(global_stack.getId()):
                 user_extruder_container = extruder.getTop()
                 if user_extruder_container:
                     user_extruder_container.update()
@@ -686,16 +691,13 @@ class CuraApplication(QtApplication):
 
         self.showSplashMessage(self._i18n_catalog.i18nc("@info:progress", "Loading interface..."))
 
-        # Initialise extruder so as to listen to global container stack changes before the first global container stack is set.
-        ExtruderManager.getInstance()
+        qmlRegisterSingletonType(ExtruderManager, "Cura", 1, 0, "ExtruderManager", self.getExtruderManager)
         qmlRegisterSingletonType(MachineManager, "Cura", 1, 0, "MachineManager", self.getMachineManager)
         qmlRegisterSingletonType(MaterialManager, "Cura", 1, 0, "MaterialManager", self.getMaterialManager)
-        qmlRegisterSingletonType(SettingInheritanceManager, "Cura", 1, 0, "SettingInheritanceManager",
-                                 self.getSettingInheritanceManager)
-        qmlRegisterSingletonType(SimpleModeSettingsManager, "Cura", 1, 2, "SimpleModeSettingsManager",
-                                 self.getSimpleModeSettingsManager)
-
+        qmlRegisterSingletonType(SettingInheritanceManager, "Cura", 1, 0, "SettingInheritanceManager", self.getSettingInheritanceManager)
+        qmlRegisterSingletonType(SimpleModeSettingsManager, "Cura", 1, 2, "SimpleModeSettingsManager", self.getSimpleModeSettingsManager)
         qmlRegisterSingletonType(MachineActionManager.MachineActionManager, "Cura", 1, 0, "MachineActionManager", self.getMachineActionManager)
+
         self.setMainQml(Resources.getPath(self.ResourceTypes.QmlFiles, "Cura.qml"))
         self._qml_import_paths.append(Resources.getPath(self.ResourceTypes.QmlFiles))
         self.initializeEngine()
@@ -717,6 +719,11 @@ class CuraApplication(QtApplication):
             self._machine_manager = MachineManager.createMachineManager()
         return self._machine_manager
 
+    def getExtruderManager(self, *args):
+        if self._extruder_manager is None:
+            self._extruder_manager = ExtruderManager.createExtruderManager()
+        return self._extruder_manager
+
     def getMaterialManager(self, *args):
         if self._material_manager is None:
             self._material_manager = MaterialManager.createMaterialManager()
@@ -784,7 +791,7 @@ class CuraApplication(QtApplication):
         actions_url = QUrl.fromLocalFile(os.path.abspath(Resources.getPath(CuraApplication.ResourceTypes.QmlFiles, "Actions.qml")))
         qmlRegisterSingletonType(actions_url, "Cura", 1, 0, "Actions")
 
-        engine.rootContext().setContextProperty("ExtruderManager", ExtruderManager.getInstance())
+        # engine.rootContext().setContextProperty("ExtruderManager", ExtruderManager.getInstance())
 
         for path in Resources.getAllResourcesOfType(CuraApplication.ResourceTypes.QmlFiles):
             type_name = os.path.splitext(os.path.basename(path))[0]

cura/Settings/CuraStackBuilder.py

@@ -62,6 +62,7 @@ class CuraStackBuilder:
                 variant = "default",
                 next_stack = new_global_stack
             )
+            new_global_stack.addExtruder(new_extruder)
 
         return new_global_stack
 
@@ -79,7 +80,9 @@ class CuraStackBuilder:
         stack.setName(definition.getName())
         stack.setDefinition(definition)
         stack.addMetaDataEntry("position", definition.getMetaDataEntry("position"))
-        if "next_stack" in kwargs: #Add stacks before containers are added, since they may trigger a setting update.
+
+        if "next_stack" in kwargs:
+            # Add stacks before containers are added, since they may trigger a setting update.
             stack.setNextStack(kwargs["next_stack"])
 
         user_container = InstanceContainer(new_stack_id + "_user")

cura/Settings/ExtruderManager.py

@@ -83,18 +83,23 @@ class ExtruderManager(QObject):
     @pyqtProperty("QVariantMap", notify = extrudersChanged)
     def extruderIds(self):
         extruder_stack_ids = {}
+
         global_stack_id = Application.getInstance().getGlobalContainerStack().getId()
-        extruder_stack_ids["-1"] = global_stack_id
+
+        # TODO: remove this? - CURA-4482
+        # extruder_stack_ids["-1"] = global_stack_id
+
         if global_stack_id in self._extruder_trains:
             for position in self._extruder_trains[global_stack_id]:
                 extruder_stack_ids[position] = self._extruder_trains[global_stack_id][position].getId()
+
         return extruder_stack_ids
 
     @pyqtSlot(str, result = str)
-    def getQualityChangesIdByExtruderStackId(self, id: str) -> str:
+    def getQualityChangesIdByExtruderStackId(self, extruder_stack_id: str) -> str:
         for position in self._extruder_trains[Application.getInstance().getGlobalContainerStack().getId()]:
             extruder = self._extruder_trains[Application.getInstance().getGlobalContainerStack().getId()][position]
-            if extruder.getId() == id:
+            if extruder.getId() == extruder_stack_id:
                 return extruder.qualityChanges.getId()
 
     ##  The instance of the singleton pattern.
@@ -102,6 +107,10 @@ class ExtruderManager(QObject):
     #   It's None if the extruder manager hasn't been created yet.
     __instance = None
 
+    @staticmethod
+    def createExtruderManager():
+        return ExtruderManager()
+
     ##  Gets an instance of the extruder manager, or creates one if no instance
     #   exists yet.
     #
@@ -420,20 +429,21 @@ class ExtruderManager(QObject):
         global_stack = Application.getInstance().getGlobalContainerStack()
         container_registry = ContainerRegistry.getInstance()
 
-        if global_stack.getProperty("machine_extruder_count", "value") <= 1: #For single extrusion.
-            return [global_stack]
-
         used_extruder_stack_ids = set()
 
-        #Get the extruders of all meshes in the scene.
+        # Get the extruders of all meshes in the scene
         support_enabled = False
         support_bottom_enabled = False
         support_roof_enabled = False
+
         scene_root = Application.getInstance().getController().getScene().getRoot()
-        meshes = [node for node in DepthFirstIterator(scene_root) if type(node) is SceneNode and node.isSelectable()] #Only use the nodes that will be printed.
+
+        # Get the extruders of all printable meshes in the scene
+        meshes = [node for node in DepthFirstIterator(scene_root) if type(node) is SceneNode and node.isSelectable()]
         for mesh in meshes:
             extruder_stack_id = mesh.callDecoration("getActiveExtruder")
-            if not extruder_stack_id: #No per-object settings for this node.
+            if not extruder_stack_id:
+                # No per-object settings for this node
                 extruder_stack_id = self.extruderIds["0"]
             used_extruder_stack_ids.add(extruder_stack_id)
 
@@ -469,9 +479,10 @@ class ExtruderManager(QObject):
             if support_roof_enabled:
                 used_extruder_stack_ids.add(self.extruderIds[str(global_stack.getProperty("support_roof_extruder_nr", "value"))])
 
-        #The platform adhesion extruder. Not used if using none.
+        # The platform adhesion extruder. Not used if using none.
         if global_stack.getProperty("adhesion_type", "value") != "none":
             used_extruder_stack_ids.add(self.extruderIds[str(global_stack.getProperty("adhesion_extruder_nr", "value"))])
+
         try:
             return [container_registry.findContainerStacks(id = stack_id)[0] for stack_id in used_extruder_stack_ids]
         except IndexError:  # One or more of the extruders was not found.
@@ -518,10 +529,6 @@ class ExtruderManager(QObject):
         result = []
         machine_extruder_count = global_stack.getProperty("machine_extruder_count", "value")
 
-        # In case the printer is using one extruder, shouldn't exist active extruder stacks
-        # if machine_extruder_count == 1:
-        #     return result
-
         if global_stack and global_stack.getId() in self._extruder_trains:
             for extruder in sorted(self._extruder_trains[global_stack.getId()]):
                 result.append(self._extruder_trains[global_stack.getId()][extruder])
@@ -544,8 +551,23 @@ class ExtruderManager(QObject):
     ##  Adds the extruders of the currently active machine.
     def _addCurrentMachineExtruders(self) -> None:
         global_stack = Application.getInstance().getGlobalContainerStack()
+        extruders_changed = False
+
         if global_stack and global_stack.getBottom():
-            self.addMachineExtruders(global_stack.getBottom(), global_stack.getId())
+            container_registry = ContainerRegistry.getInstance()
+            machine_id = global_stack.getBottom().getId()
+
+            # Gets the extruder trains that we just created as well as any that still existed.
+            extruder_trains = container_registry.findContainerStacks(type = "extruder_train", machine = machine_id)
+            for extruder_train in extruder_trains:
+                self._extruder_trains[machine_id][extruder_train.getMetaDataEntry("position")] = extruder_train
+
+                # regardless of what the next stack is, we have to set it again, because of signal routing.
+                extruder_train.setNextStack(global_stack)
+                extruders_changed = True
+
+            if extruders_changed:
+                self.extrudersChanged.emit(machine_id)
 
     ##  Get all extruder values for a certain setting.
     #
@@ -560,7 +582,7 @@ class ExtruderManager(QObject):
         global_stack = Application.getInstance().getGlobalContainerStack()
 
         result = []
-        for extruder in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+        for extruder in ExtruderManager.getMachineExtruders(global_stack.getId()):
             # only include values from extruders that are "active" for the current machine instance
             if int(extruder.getMetaDataEntry("position")) >= global_stack.getProperty("machine_extruder_count", "value"):
                 continue
@@ -600,7 +622,7 @@ class ExtruderManager(QObject):
         }
 
         result = []
-        for extruder in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+        for extruder in ExtruderManager.getMachineExtruders(global_stack.getId()):
             # only include values from extruders that are "active" for the current machine instance
             if int(extruder.getMetaDataEntry("position")) >= global_stack.getProperty("machine_extruder_count", "value", context = context):
                 continue
@@ -624,7 +646,7 @@ class ExtruderManager(QObject):
     #
     #   This is exposed to qml for display purposes
     #
-    #   \param key The key of the setting to retieve values for.
+    #   \param key The key of the setting to retrieve values for.
     #
     #   \return String representing the extruder values
     @pyqtSlot(str, result="QVariant")

cura/Settings/ExtrudersModel.py

@@ -66,7 +66,7 @@ class ExtrudersModel(UM.Qt.ListModel.ListModel):
         self._update_extruder_timer = QTimer()
         self._update_extruder_timer.setInterval(100)
         self._update_extruder_timer.setSingleShot(True)
-        self._update_extruder_timer.connect(self.__updateExtruders)
+        self._update_extruder_timer.timeout.connect(self.__updateExtruders)
 
         self._add_global = False
         self._simple_names = False

cura/Settings/MachineManager.py

@@ -1173,7 +1173,7 @@ class MachineManager(QObject):
             return containers[0].getBottom().getId()
 
     @staticmethod
-    def createMachineManager(engine=None, script_engine=None):
+    def createMachineManager():
         return MachineManager()
 
     @deprecated("Use ExtruderStack.material = ... and it won't be necessary", "2.7")

cura/Settings/QualityAndUserProfilesModel.py

@@ -22,47 +22,23 @@ class QualityAndUserProfilesModel(ProfilesModel):
 
         # Fetch the list of quality changes.
         quality_manager = QualityManager.getInstance()
-        machine_definition = quality_manager.getParentMachineDefinition(global_container_stack.getBottom())
+        machine_definition = quality_manager.getParentMachineDefinition(global_container_stack.definition)
         quality_changes_list = quality_manager.findAllQualityChangesForMachine(machine_definition)
 
-        # Detecting if the machine has multiple extrusion
-        multiple_extrusion = global_container_stack.getProperty("machine_extruder_count", "value") > 1
-        # Get the  list of extruders
         extruder_manager = ExtruderManager.getInstance()
         active_extruder = extruder_manager.getActiveExtruderStack()
-        extruder_stacks = extruder_manager.getActiveExtruderStacks()
-        if multiple_extrusion:
-            # Place the active extruder at the front of the list.
-            # This is a workaround checking if there is an active_extruder or not before moving it to the front of the list.
-            # Actually, when a printer has multiple extruders, should exist always an active_extruder. However, in some
-            # cases the active_extruder is still None.
-            if active_extruder in extruder_stacks:
-                extruder_stacks.remove(active_extruder)
-            new_extruder_stacks = []
-            if active_extruder is not None:
-                new_extruder_stacks = [active_extruder]
-            else:
-                # if there is no active extruder, use the first one in the active extruder stacks
-                active_extruder = extruder_stacks[0]
-            extruder_stacks = new_extruder_stacks + extruder_stacks
+        extruder_stacks = self._getOrderedExtruderStacksList()
 
-        # Fetch the list of useable qualities across all extruders.
+        # Fetch the list of usable qualities across all extruders.
         # The actual list of quality profiles come from the first extruder in the extruder list.
-        quality_list = quality_manager.findAllUsableQualitiesForMachineAndExtruders(global_container_stack,
-                                                                                                  extruder_stacks)
+        quality_list = quality_manager.findAllUsableQualitiesForMachineAndExtruders(global_container_stack, extruder_stacks)
 
         # Filter the quality_change by the list of available quality_types
         quality_type_set = set([x.getMetaDataEntry("quality_type") for x in quality_list])
-
-        if multiple_extrusion:
-            # If the printer has multiple extruders then quality changes related to the current extruder are kept
-            filtered_quality_changes = [qc for qc in quality_changes_list if qc.getMetaDataEntry("quality_type") in quality_type_set and
-                                        qc.getMetaDataEntry("extruder") is not None and
-                                        (qc.getMetaDataEntry("extruder") == active_extruder.definition.getMetaDataEntry("quality_definition") or
-                                         qc.getMetaDataEntry("extruder") == active_extruder.definition.getId())]
-        else:
-            # If not, the quality changes of the global stack are selected
-            filtered_quality_changes = [qc for qc in quality_changes_list if qc.getMetaDataEntry("quality_type") in quality_type_set and
-                                        qc.getMetaDataEntry("extruder") is None]
+        filtered_quality_changes = [qc for qc in quality_changes_list if
+                                    qc.getMetaDataEntry("quality_type") in quality_type_set and
+                                    qc.getMetaDataEntry("extruder") is not None and
+                                    (qc.getMetaDataEntry("extruder") == active_extruder.definition.getMetaDataEntry("quality_definition") or
+                                     qc.getMetaDataEntry("extruder") == active_extruder.definition.getId())]
 
         return quality_list + filtered_quality_changes

cura/Settings/SettingInheritanceManager.py

@@ -47,21 +47,20 @@ class SettingInheritanceManager(QObject):
 
     @pyqtSlot(str, str, result = "QStringList")
     def getOverridesForExtruder(self, key, extruder_index):
-        multi_extrusion = self._global_container_stack.getProperty("machine_extruder_count", "value") > 1
-        if not multi_extrusion:
-            return self._settings_with_inheritance_warning
-        extruder = ExtruderManager.getInstance().getExtruderStack(extruder_index)
-        if not extruder:
+        result = []
+
+        extruder_stack = ExtruderManager.getInstance().getExtruderStack(extruder_index)
+        if not extruder_stack:
             Logger.log("w", "Unable to find extruder for current machine with index %s", extruder_index)
-            return []
+            return result
 
-        definitions = self._global_container_stack.definition.findDefinitions(key=key)
+        definitions = self._global_container_stack.definition.findDefinitions(key = key)
         if not definitions:
             Logger.log("w", "Could not find definition for key [%s] (2)", key)
-            return []
-        result = []
+            return result
+
         for key in definitions[0].getAllKeys():
-            if self._settingIsOverwritingInheritance(key, extruder):
+            if self._settingIsOverwritingInheritance(key, extruder_stack):
                 result.append(key)
 
         return result