From 73f12ffd99e0b4c7fba37dd845f36928d2d884e4 Mon Sep 17 00:00:00 2001
From: Ghostkeeper <rubend@tutanota.com>
Date: Thu, 2 Jun 2016 11:15:52 +0200
Subject: [PATCH] Incorporate switching of global extruder stack

When the global extruder stack switches, we need to re-connect the reloading of extruders to the new containersChanged signal of the new global container stack. This now also bootstraps the listening for the first time, when the global container stack changes from None to the first stack.

Contributes to issues CURA-1278 and CURA-351.
---
 cura/ExtruderManager.py | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/cura/ExtruderManager.py b/cura/ExtruderManager.py
index 4d95a9008d..71b636ad6f 100644
--- a/cura/ExtruderManager.py
+++ b/cura/ExtruderManager.py
@@ -19,9 +19,17 @@ class ExtruderManager:
     ##  Registers listeners and such to listen to changes to the extruders.
     def __init__(self):
         self._extruders = [] #Extruders for the current machine.
+        self._global_container_stack = None
 
-        Application.getInstance().getGlobalContainerStack().containersChanged.connect(self._reloadExtruders) #When the current machine changes, we need to reload all extruders belonging to the new machine.
-        self._reloadExtruders()
+        Application.getInstance().globalContainerStackChanged.connect(self._reconnectExtruderReload) #When the current machine changes, we need to reload all extruders belonging to the new machine.
+
+    ##  When the global container stack changes, this reconnects to the new
+    #   signal for containers changing.
+    def _reconnectExtruderReload(self):
+        if self._global_container_stack:
+            self._global_container_stack.containersChanged.disconnect(self._reloadExtruders) #Disconnect from the old global container stack.
+        self._global_container_stack = Application.getInstance().getGlobalContainerStack()
+        self._global_container_stack.containersChanged.connect(self._reloadExtruders) #When the current machine changes, we need to reload all extruders belonging to the new machine.
 
     ##  (Re)loads all extruders of the currently active machine.
     #
@@ -30,12 +38,11 @@ class ExtruderManager:
     #   list of extruders.
     def _reloadExtruders(self):
         self._extruders = []
-        global_container_stack = Application.getInstance().getGlobalContainerStack()
-        if not global_container_stack: #No machine has been added yet.
+        if not self._global_container_stack: #No machine has been added yet.
             return #Then leave them empty!
 
         #Get the extruder definitions belonging to the current machine.
-        machine = global_container_stack.getBottom()
+        machine = self._global_container_stack.getBottom()
         extruder_train_ids = machine.getMetaData("machine_extruder_trains")
         for extruder_train_id in extruder_train_ids:
             extruder_definitions = ContainerRegistry.getInstance().findDefinitionContainers(id = extruder_train_id) #Should be only 1 definition if IDs are unique, but add the whole list anyway.