Add basic extruder implementation

This implementation can load an extruder from a definition container, but doesn't expose anything (yet). It is intended to function in much the same way as a definition model, so it must expose its relevant properties to QML.

Contributes to issues CURA-1278 and CURA-351.

cura/Extruder.py

@@ -0,0 +1,85 @@
+# Copyright (c) 2016 Ultimaker B.V.
+# Cura is released under the terms of the AGPLv3 or higher.
+
+import re #To parse container registry names to increment the duplicates-resolving number.
+
+import UM.Settings.ContainerRegistry #To search for nozzles, materials, etc.
+import UM.Settings.ContainerStack #To create a container stack for this extruder.
+
+class Extruder:
+    ##  Creates a new extruder from the specified definition container.
+    #
+    #   \param definition The definition container defining this extruder.
+    def __init__(self, definition):
+        self._definition = definition
+
+        container_registry = UM.Settings.ContainerRegistry.getInstance()
+
+        #Find the nozzles that fit on this extruder.
+        self._nozzles = container_registry.findInstanceContainers(type = "nozzle", definitions = "*," + definition.getId() + ",*")
+        self._nozzles += container_registry.findInstanceContainers(type = "nozzle", definitions = "*," + definition.getId())
+        self._nozzles += container_registry.findInstanceContainers(type = "nozzle", definitions = definition.getId() + ",*")
+        self._nozzles += container_registry.findInstanceContainers(type = "nozzle", definitions = definition.getId())
+
+        #Create a container stack for this extruder.
+        self._container_stack = UM.Settings.ContainerStack(self._uniqueName(self._definition.getId()))
+        self._container_stack.addMetaDataEntry("type", "extruder_train")
+        self._container_stack.addContainer(self._definition)
+
+        #Find the nozzle to use for this extruder.
+        self._nozzle = container_registry.getEmptyInstanceContainer()
+        if len(self._nozzles) >= 1: #First add any extruder. Later, overwrite with preference if the preference is valid.
+            self._nozzle = self._nozzles[0]
+        preferred_nozzle_id = self._definition.getMetaDataEntry("preferred_nozzle")
+        if preferred_nozzle_id:
+            for nozzle in self._nozzles:
+                if nozzle.getId() == preferred_nozzle_id:
+                    self._nozzle = nozzle
+                    break
+        self._container_stack.addContainer(self._nozzle)
+
+        #Find a material to use for this nozzle.
+        self._material = container_registry.getEmptyInstanceContainer()
+        all_materials = container_registry.findInstanceContainers(type = "material")
+        if len(all_materials) >= 1:
+            self._material = all_materials[0]
+        preferred_material_id = self._definition.getMetaDataEntry("preferred_material")
+        if preferred_material_id:
+            preferred_material = container_registry.findInstanceContainers(type = "material", id = preferred_material_id.lower())
+            if len(preferred_material) >= 1:
+                self._material = preferred_material[0]
+        self._container_stack.addContainer(self._material)
+
+        #Find a quality to use for this extruder.
+        self._quality = container_registry.getEmptyInstanceContainer()
+        all_qualities = container_registry.findInstanceContainers(type = "quality")
+        if len(all_qualities) >= 1:
+            self._quality = all_qualities[0]
+        preferred_quality_id = self._definition.getMetaDataEntry("preferred_quality")
+        if preferred_quality_id:
+            preferred_quality = container_registry.findInstanceContainers(type = "quality", id = preferred_quality_id.lower())
+            if len(preferred_quality) >= 1:
+                self._quality = preferred_quality[0]
+        self._container_stack.addContainer(self._quality)
+
+    ##  Finds a unique name for an extruder stack.
+    #
+    #   \param extruder An extruder definition to design a name for.
+    #   \return A name for an extruder stack that is unique and reasonably
+    #   human-readable.
+    def _uniqueName(self, extruder):
+        container_registry = UM.Settings.ContainerRegistry.getInstance()
+
+        name = extruder.getName().strip()
+        num_check = re.compile("(.*?)\s*#\d$").match(name)
+        if num_check: #There is a number in the name.
+            name = num_check.group(1) #Filter out the number.
+        if name == "": #Wait, that deleted everything!
+            name = "Extruder"
+        unique_name = name
+
+        i = 1
+        while container_registry.findContainers(id = unique_name) or container_registry.findContainers(name = unique_name): #A container already has this name.
+            i += 1 #Try next numbering.
+            unique_name = "%s #%d" % (name, i) #Fill name like this: "Extruder #2".
+        return unique_name