'Add a new node to our canvas.'

def addNamedNode(self, node, name, x, y):

    icon = self.nodeIcon(node, name)
    item = self.canvas.create_window(x, y, anchor='c', window=icon, tags=node)
    self.widgetToItem[icon] = item
    self.itemToWidget[item] = icon
    icon.links = {}
