Added the initial code for the Node class.

game/gbe/nodes.py

+
+
+NODETYPE_NODE = "NODE"
+
+class NodeError(Exception):
+    pass
+
+
+class Node:
+    def __init__(self, name="Node", parent=None):
+        self._children = []
+        self.name = name
+
+    @property
+    def parent(self):
+        return self._parent
+
+    @parent.setter
+    def parent(self, value):
+        try:
+            self.parent_to_node(value)
+        except NodeError as e:
+            raise e
+
+    @property
+    def name(self):
+        return self._name
+
+    @name.setter
+    def name(self, value):
+        self._name = value
+
+    def parent_to_node(self, parent, allow_reparenting=False):
+        if not isinstance(value, Node):
+            raise NodeError("Node may only parent to another Node instance.")
+        if self._parent is None:
+            self._parent = value
+        elif self._parent != value:
+            if allow_Reparenting == False:
+                raise NodeError("Node already assigned a parent Node.")
+            if self._parent.remove_node(self) != self:
+                raise NodeError("Failed to remove self from current parent.")
+            parent.attach_node(self)
+
+
+    def attach_node(self, node, reparent=False, index=-1):
+        if node.parent is not None:
+            if node.parent == self:
+                return # Nothing to do. Given node already parented to this node.
+            if reparent = False:
+                raise NodeError("Node already parented.")
+            if node.parent.remove_node(node) != node:
+                raise NodeError("Failed to remove given node from it's current parent.")
+        node._parent = self
+        if index < 0 or index >= len(self._children):
+            self._children.append(node)
+        else:
+            self._children.insert(index, node)
+
+    def remove_node(self, node):
+        if node.parent != self:
+            if node.parent == None:
+                raise NodeError("Cannot remove an unparented node.")
+            return node.parent.remove_node(node)
+        if node in self._children:
+            self._children.remove(node)
+            node._parent = None
+            return node
+
+
+
+
+