WIP: Simplify global stack and extruder stack activation and fixes

cura/Settings/CuraStackBuilder.py

@@ -102,6 +102,7 @@ class CuraStackBuilder:
                 variant_container = variant_container,
                 material_container = material_container,
                 quality_container = application.empty_quality_container,
+                global_stack = new_global_stack,
             )
             new_extruder.setNextStack(new_global_stack)
             new_global_stack.addExtruder(new_extruder)
@@ -133,11 +134,11 @@ class CuraStackBuilder:
     @classmethod
     def createExtruderStack(cls, new_stack_id: str, extruder_definition: DefinitionContainerInterface, machine_definition_id: str,
                             position: int,
-                            variant_container, material_container, quality_container) -> ExtruderStack:
+                            variant_container, material_container, quality_container, global_stack) -> ExtruderStack:
         from cura.CuraApplication import CuraApplication
         application = CuraApplication.getInstance()
 
-        stack = ExtruderStack(new_stack_id)
+        stack = ExtruderStack(new_stack_id, parent = global_stack)
         stack.setName(extruder_definition.getName())
         stack.setDefinition(extruder_definition)
 

cura/Settings/ExtruderManager.py

@@ -36,22 +36,15 @@ class ExtruderManager(QObject):
         self._global_container_stack_definition_id = None
         self._addCurrentMachineExtruders()
 
-        Application.getInstance().globalContainerStackChanged.connect(self.__globalContainerStackChanged)
+        #Application.getInstance().globalContainerStackChanged.connect(self._globalContainerStackChanged)
         Selection.selectionChanged.connect(self.resetSelectedObjectExtruders)
 
     ##  Signal to notify other components when the list of extruders for a machine definition changes.
     extrudersChanged = pyqtSignal(QVariant)
 
-    ## Signal to notify other components when the global container stack is switched to a definition
-    #  that has different extruders than the previous global container stack
-    globalContainerStackDefinitionChanged = pyqtSignal()
-
     ##  Notify when the user switches the currently active extruder.
     activeExtruderChanged = pyqtSignal()
 
-    ## The signal notifies subscribers if extruders are added
-    extrudersAdded = pyqtSignal()
-
     ##  Gets the unique identifier of the currently active extruder stack.
     #
     #   The currently active extruder stack is the stack that is currently being
@@ -371,11 +364,10 @@ class ExtruderManager(QObject):
 
         return result[:machine_extruder_count]
 
-    def __globalContainerStackChanged(self) -> None:
+    def _globalContainerStackChanged(self) -> None:
         global_container_stack = Application.getInstance().getGlobalContainerStack()
         if global_container_stack and global_container_stack.getBottom() and global_container_stack.getBottom().getId() != self._global_container_stack_definition_id:
             self._global_container_stack_definition_id = global_container_stack.getBottom().getId()
-            self.globalContainerStackDefinitionChanged.emit()
 
         # If the global container changed, the machine changed and might have extruders that were not registered yet
         self._addCurrentMachineExtruders()
@@ -415,7 +407,6 @@ class ExtruderManager(QObject):
 
             if extruders_changed:
                 self.extrudersChanged.emit(global_stack_id)
-                self.extrudersAdded.emit()
                 self.setActiveExtruderIndex(0)
 
     ##  Get all extruder values for a certain setting.

cura/Settings/ExtruderStack.py

@@ -3,7 +3,6 @@
 
 from typing import Any, TYPE_CHECKING, Optional
 
-from UM.Application import Application
 from UM.Decorators import override
 from UM.MimeTypeDatabase import MimeType, MimeTypeDatabase
 from UM.Settings.ContainerStack import ContainerStack
@@ -34,7 +33,7 @@ class ExtruderStack(CuraContainerStack):
     #
     #   This will set the next stack and ensure that we register this stack as an extruder.
     @override(ContainerStack)
-    def setNextStack(self, stack: ContainerStack) -> None:
+    def setNextStack(self, stack: CuraContainerStack) -> None:
         super().setNextStack(stack)
         stack.addExtruder(self)
         self.addMetaDataEntry("machine", stack.id)

cura/Settings/MachineManager.py

@@ -283,6 +283,7 @@ class MachineManager(QObject):
         containers = container_registry.findContainerStacks(id = stack_id)
         if containers:
             Application.getInstance().setGlobalContainerStack(containers[0])
+            ExtruderManager.getInstance()._globalContainerStackChanged()
 
         self.__emitChangedSignals()
 
@@ -877,9 +878,10 @@ class MachineManager(QObject):
 
     @pyqtSlot(int, result = QObject)
     def getExtruder(self, position: int):
+        extruder = None
         if self._global_container_stack:
-            return self._global_container_stack.extruders.get(str(position))
-        return None
+            extruder = self._global_container_stack.extruders.get(str(position))
+        return extruder
 
     def _onMachineNameChanged(self):
         self.globalContainerChanged.emit()

plugins/CuraEngineBackend/CuraEngineBackend.py

@@ -88,7 +88,6 @@ class CuraEngineBackend(QObject, Backend):
         #
         self._global_container_stack = None
         Application.getInstance().globalContainerStackChanged.connect(self._onGlobalStackChanged)
-        Application.getInstance().getExtruderManager().extrudersAdded.connect(self._onGlobalStackChanged)
         self._onGlobalStackChanged()
 
         Application.getInstance().stacksValidationFinished.connect(self._onStackErrorCheckFinished)

resources/qml/Menus/NozzleMenu.qml

@@ -13,7 +13,8 @@ Menu
     title: "Nozzle"
 
     property int extruderIndex: 0
-    property var extruderStack: Cura.MachineManager.getExtruder(menu.extruderIndex)
+    property QtObject extruderStack: Cura.MachineManager.getExtruder(menu.extruderIndex)
+    property bool hasExtruderStack: extruderStack != null
 
     Cura.NozzleModel
     {
@@ -24,7 +25,7 @@ Menu
     {
         target: Cura.MachineManager
         onGlobalContainerChanged: {
-            menu.extruderStack = Cura.MachineManager.getExtruder(extruderIndex);
+            menu.extruderStack = Cura.MachineManager.getExtruder(menu.extruderIndex);
         }
     }
 
@@ -36,7 +37,7 @@ Menu
         {
             text: model.hotend_name
             checkable: true
-            checked: extruderStack.variant.name == model.hotend_name
+            checked: menu.hasExtruderStack && extruderStack.variant.name == model.hotend_name
             exclusiveGroup: group
             onTriggered: {
                 Cura.MachineManager.setVariantGroup(extruderIndex, model.container_node);