/*
 * DefaultVectorModel.java, (c) Raimond Reichert 1999
 */
package mldemo;

import java.util.*;
import java.lang.ref.*;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
  * Implements <code>VectorModel</code> the "normal" way, ie, using
  * a <code>Vector</code> to hold the references to the
  * <code>VectorModel.Listener</code>s.
  *
  * @author Raimond Reichert
  */
public class DefaultVectorModel implements VectorModel {

  private Vector vector;
  private Vector listeners;

  public DefaultVectorModel() {
    vector = new Vector();
    listeners = new Vector();
  } // DefaultVectorModel //

  public void addElement (Object object) {
    vector.addElement (object);
    fireElementAdded (object);
  } // addElement //

  public void removeElement (Object object) {
    vector.removeElement (object);
    fireElementRemoved (object);
  } // removeElement //

  public Object elementAt (int index) {
    return vector.elementAt (index);
  } // elementAt //

  public int size() {
    return vector.size();
  } // size //

  public void addListener (VectorModel.Listener l) {
    listeners.addElement (l);
  } // addListener //

  public void removeListener (VectorModel.Listener l) {
    listeners.removeElement (l);
  } // removeListener //

  protected void fireElementAdded (Object object) {
    VectorModel.Event e = null;
    int size = listeners.size();
    for (int i = 0; i < size; i++) {
      if (e == null) // lazily create event
        e = new VectorModel.Event (this, object);
      ((VectorModel.Listener)listeners.elementAt(i)).elementAdded (e);
    }
  } // fireElementAdded //

  protected void fireElementRemoved (Object object) {
    VectorModel.Event e = null;
    int size = listeners.size();
    for (int i = 0; i < size; i++) {
      if (e == null) // lazily create event
        e = new VectorModel.Event (this, object);
      ((VectorModel.Listener)listeners.elementAt(i)).elementRemoved (e);
    }
  } // fireElementRemoved //

} // DefaultVectorModel //