minwin-gcc-5-2/libjava/classpath/javax/swing/AbstractSpinnerModel.java

/* AbstractSpinnerModel.java --
   Copyright (C) 2004, 2006, Free Software Foundation, Inc.

This file is part of GNU Classpath.

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it under the terms of the GNU General Public License as published by
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General Public License for more details.

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02110-1301 USA.

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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
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package javax.swing;

import java.util.EventListener;

import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.EventListenerList;

/**
 * Provides standard implementations for some of the methods in
 * {@link SpinnerModel}.
 *
 * @since 1.4
 *
 * @author Ka-Hing Cheung
 */
public abstract class AbstractSpinnerModel implements SpinnerModel
{
  private ChangeEvent changeEvent = new ChangeEvent(this);

  /** Stores the listeners registered with the model. */
  protected EventListenerList listenerList = new EventListenerList();

  /**
   * Creates an <code>AbstractSpinnerModel</code>.
   */
  public AbstractSpinnerModel()
  {
    // Nothing to do here.
  }

  /**
   * Registers a <code>ChangeListener</code> with the model so that it will
   * receive {@link ChangeEvent} notifications when the model changes.
   *
   * @param listener the listener to add (<code>null</code> is ignored).
   */
  public void addChangeListener(ChangeListener listener)
  {
    listenerList.add(ChangeListener.class, listener);
  }

  /**
   * Gets all the listeners that are of a particular type.
   *
   * @param c the type of listener
   * @return the listeners that are of the specific type
   */
  public <T extends EventListener> T[] getListeners(Class<T> c)
  {
    return listenerList.getListeners(c);
  }

  /**
   * Gets all the <code>ChangeListener</code>s.
   *
   * @return all the <code>ChangeListener</code>s
   */
  public ChangeListener[] getChangeListeners()
  {
    return (ChangeListener[]) listenerList.getListeners(ChangeListener.class);
  }

  /**
   * Remove a particular listener.
   *
   * @param listener the listener to remove
   */
  public void removeChangeListener(ChangeListener listener)
  {
    listenerList.remove(ChangeListener.class, listener);
  }

  /**
   * Fires a <code>ChangeEvent</code> to all the <code>ChangeListener</code>s
   * added to this model
   */
  protected void fireStateChanged()
  {
    ChangeListener[] listeners = getChangeListeners();

    for (int i = 0; i < listeners.length; ++i)
      listeners[i].stateChanged(changeEvent);
  }
}