Implement category model

Not just pseudocode. However this code is not yet tested.

Contributes to issue CURA-6091.

cura/Machines/Models/IntentCategoryModel.py

@@ -1,14 +1,47 @@
 #Copyright (c) 2019 Ultimaker B.V.
 #Cura is released under the terms of the LGPLv3 or higher.
 
-from UM.Qt.ListModel import ListModel
+from PyQt5.QtCore import Qt
+import collections
+
 from cura.Settings.IntentManager import IntentManager
+from UM.Qt.ListModel import ListModel
+
+from UM.i18n import i18nCatalog
+catalog = i18nCatalog("cura")
 
+##  Lists the intent categories that are available for the current printer
+#   configuration.
 class IntentCategoryModel(ListModel):
+    NameRole = Qt.UserRole + 1
+    IntentCategoryRole = Qt.UserRole + 2
+    WeightRole = Qt.UserRole + 3
+
+    #Translations to user-visible string. Ordered by weight.
+    #TODO: Create a solution for this name and weight to be used dynamically.
+    name_translation = collections.OrderedDict()
+    name_translation["default"] = catalog.i18nc("@label", "Default")
+    name_translation["engineering"] = catalog.i18nc("@label", "Engineering")
+    name_translation["smooth"] = catalog.i18nc("@label", "Smooth")
+
+    ##  Creates a new model for a certain intent category.
+    #   \param The category to list the intent profiles for.
     def __init__(self, intent_category: str):
+        super().__init__()
         self._intent_category = intent_category
 
+        self.addRoleName(self.NameRole, "name")
+        self.addRoleName(self.IntentCategoryRole, "intent_category")
+        self.addRoleName(self.WeightRole, "weight")
+
+    ##  Updates the list of intents.
     def update(self):
-        available_intents = IntentManager.getInstance().currentAvailableIntents()
-        result = filter(lambda intent: intent.getMetaDataEntry("intent_category") == self._intent_category, available_intents)
+        available_categories = IntentManager.getInstance().currentAvailableIntentCategories()
+        result = []
+        for category in available_categories:
+            result.append({
+                "name": self.name_translation.get(category, catalog.i18nc("@label", "Unknown")),
+                "intent_category": category,
+                "weight": list(self.name_translation.items()).index(category)
+            })
         super().update(result)