/**
* Add an item before the supplied node
*
* @param node The node to add before
* @param value The value to add
*/
private void addBefore(DoubleNode<E> node, E value) {
if (node == head) {
throw new IllegalArgumentException("Cannot add node before head");
}
DoubleNode<E> n = new DoubleNode<>(value);
node.getPrev().setNext(n);
n.setPrev(node.getPrev());
node.setPrev(n);
n.setNext(node);
size++;
}
/** Constructor */
public DoubleList() {
head = new DoubleNode<>(null);
tail = new DoubleNode<>(null);
head.setNext(tail);
tail.setPrev(head);
size = 0;
}
/**
* Add an item after the supplied node
*
* @param node The node to add after
* @param value The value to add
*/
private void addAfter(DoubleNode<E> node, E value) {
if (node == tail) {
throw new IllegalArgumentException("Cannot add node after tail");
}
DoubleNode<E> n = new DoubleNode<>(value);
node.getNext().setPrev(n);
n.setNext(node.getNext());
node.setNext(n);
n.setPrev(node);
size++;
}