Goldbox64/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