heapnode.java

OpenJGraph是一个开源的Java库

package salvo.jesus.util;

import java.io.*;

/**
 * A node in a <tt>Heap</tt>, encapsulating the actual object represented by
 * the noode plus the priority of the node in the heap.
 *
 * @author  Jesus M. Salvo Jr.
 */

public class HeapNode implements Serializable {
  /**
   * The actual object encapsulated by the <tt>HeapNode</tt>.
   */
  Object    node;

  /**
   * The priority of the <tt>HeapNode</tt>
   */
  double    priority;

  /**
   * Creates a <tt>HeapNode</tt> with a specified priority and encapsulating
   * an object.
   *
   * @param   priority  The priority of the node in the heap, determining the
   *                    position of the node within the heap.
   * @param   node      The actual Object encapsulated by the node.
   */
  public HeapNode( Object node, double priority ) {
    this.node = node;
    this.priority = priority;
  }


  /**
   * Returns the object encapsultaed by this <tt>HeapNode</tt>.
   */
  public Object getObject() {
    return this.node;
  }

  /**
   * Returns the priority of the <tt>HeapNode</tt> within the <tt>Heap</tt>.
   */
  public double getPriority() {
    return this.priority;
  }

  /**
   * Modifies the priority of the <tt>HeapNode</tt> within the <tt>Heap</tt>.
   * <p>
   * This method simply sets the <tt>priority</tt> attribute of the node.
   * This will not necessarily fixup the <tt>Heap</tt> such that this
   * <tt>HeapNode</tt> will be in its new position. To achieve that effect,
   * call <tt>Heap.setPriority( HeapNode )</tt>.
   */
  public void setPriority( double priority ) {
    this.priority = priority;
  }

  /**
   * Returns a <tt>String</tt> representation of this <tt>HeapNode</tt>.
   */
  public String toString() {
    return "Node: " + node + "; Weight: " + this.priority;
  }
}