/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

package com.sun.org.apache.bcel.internal.classfile;

import  com.sun.org.apache.bcel.internal.Constants;

import  java.io.*;

/**

 * This class represents a (PC offset, line number) pair, i.e., a line number in

 * the source that corresponds to a relative address in the byte code. This

 * is used for debugging purposes.

 *

 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>

 * @see     LineNumberTable

 */

public final class LineNumber implements Cloneable, Node, Serializable {

  private int start_pc;    // Program Counter (PC) corresponds to line

  private int line_number; // number in source file

  /**

   * Initialize from another object.

   */

  public LineNumber(LineNumber c) {

    this(c.getStartPC(), c.getLineNumber());

  }

  /**

   * Construct object from file stream.

   * @param file Input stream

   * @throws IOException

   */

  LineNumber(DataInputStream file) throws IOException

  {

    this(file.readUnsignedShort(), file.readUnsignedShort());

  }

  /**

   * @param start_pc Program Counter (PC) corresponds to

   * @param line_number line number in source file

   */

  public LineNumber(int start_pc, int line_number)

  {

    this.start_pc    = start_pc;

    this.line_number = line_number;

  }

  /**

   * Called by objects that are traversing the nodes of the tree implicitely

   * defined by the contents of a Java class. I.e., the hierarchy of methods,

   * fields, attributes, etc. spawns a tree of objects.

   *

   * @param v Visitor object

   */

  public void accept(Visitor v) {

    v.visitLineNumber(this);

  }

  /**

   * Dump line number/pc pair to file stream in binary format.

   *

   * @param file Output file stream

   * @throws IOException

   */

  public final void dump(DataOutputStream file) throws IOException

  {

    file.writeShort(start_pc);

    file.writeShort(line_number);

  }

  /**

   * @return Corresponding source line

   */

  public final int getLineNumber() { return line_number; }

  /**

   * @return PC in code

   */

  public final int getStartPC() { return start_pc; }

  /**

   * @param line_number.

   */

  public final void setLineNumber(int line_number) {

    this.line_number = line_number;

  }

  /**

   * @param start_pc.

   */

  public final void setStartPC(int start_pc) {

    this.start_pc = start_pc;

  }

  /**

   * @return String representation

   */

  public final String toString() {

    return "LineNumber(" + start_pc + ", " + line_number + ")";

  }

  /**

   * @return deep copy of this object

   */

  public LineNumber copy() {

    try {

      return (LineNumber)clone();

    } catch(CloneNotSupportedException e) {}

    return null;

  }

}