package Queue;

/**
 * Class QNodeImpl represents a double linked list node.  This class
 * is used in the implementation of the queue data structure.
 *
 * @author Thomas Wang
 * @version 0.55
 */
public class QNodeImpl
{
  /** the element of the node */
  public Object elem;

  /** the previous pointer */
  public QNodeImpl prev;

  /** the next pointer */
  public QNodeImpl next;

  /**
   * Constructor, given the content of the node
   * @param content the content of the node
   */
  public QNodeImpl(Object content)
  {
    this.elem = content;
    this.prev = null;
    this.next = null;
  }

  /**
   * Constructor, given the content of the node, and both links
   * @param content the content of the node
   * @param p the previous link
   * @param n the next link
   */
  public QNodeImpl(Object content, QNodeImpl p, QNodeImpl n)
  {
    this.elem = content;
    this.prev = p;
    this.next = n;
  }

  /**
   * Method remove() will remove the current node from the queue.
   */
  public void remove()
  {
    this.next.prev = this.prev;
    this.prev.next = this.next;
    this.prev = this.next = null;
  }

  /**
   * Method insert() will insert the current node into the queue,
   * given the previous node, and the next node.
   *
   * @param prevnode the previous node
   * @param nextnode the next node
   */
  public void insert(QNodeImpl prevnode, QNodeImpl nextnode)
  {
    prevnode.next = nextnode.prev = this;
    this.prev = prevnode;
    this.next = nextnode;
  }

}