CURA-4104 added first sucky build plate selection options

cura/Scene/BuildPlateDecorator.py

@@ -0,0 +1,34 @@
+from UM.Scene.SceneNodeDecorator import SceneNodeDecorator
+from UM.Scene.Selection import Selection
+
+
+class BuildPlateDecorator(SceneNodeDecorator):
+    def __init__(self):
+        super().__init__()
+        self._build_plate_number = -1
+
+    def setBuildPlateNumber(self, nr):
+        self._build_plate_number = nr
+        # self.getNode().childrenChanged.connect(self._onChildrenChanged)
+
+    def getBuildPlateNumber(self):
+        return self._build_plate_number
+
+    # def setNode(self, node):
+    #     super().setNode(node)
+    #     self.getNode().childrenChanged.connect(self._onChildrenChanged)
+
+    # def _onChildrenChanged(self, node):
+    #     if not self.getNode().hasChildren():
+    #         # A group that no longer has children may remove itself from the scene
+    #         self._old_parent = self.getNode().getParent()
+    #         self.getNode().setParent(None)
+    #         Selection.remove(self.getNode())
+    #     else:
+    #         # A group that has removed itself from the scene because it had no children may add itself back to the scene when a child is added to it
+    #         if not self.getNode().getParent() and self._old_parent:
+    #             self.getNode().setParent(self._old_parent)
+    #             self._old_parent = None
+
+    def __deepcopy__(self, memo):
+        return BuildPlateDecorator()