Only variants of active machine are now shown

CURA-1278

cura/MachineManagerModel.py

@@ -105,6 +105,10 @@ class MachineManagerModel(QObject):
         if containers:
             containers[0].setName(new_name)
 
+    @pyqtProperty(str, notify=globalContainerChanged)
+    def activeMachineDefinitionId(self):
+        return Application.getInstance().getGlobalContainerStack().getContainers()[-1].getId()
+
     @pyqtSlot(str)
     def removeMachine(self, machine_id):
         ContainerRegistry.getInstance().removeContainer(machine_id)

resources/qml/SidebarHeader.qml

@@ -145,9 +145,12 @@ Item
                         id: variantSelectionInstantiator
                         model: UM.InstanceContainersModel
                         {
-                            filter: {"type": "variant"}
+                            filter:
+                            {
+                                "type": "variant",
+                                "definition": Cura.MachineManager.activeMachineDefinitionId //Only show variants of this machine
+                            }
                         }
-//                         model: UM.MachineVariantsModel { id: variantsModel }
                         MenuItem
                         {
                             text: model.name;