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	/*
	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package javax.swing;

	import javax.swing.event.*;
	import java.io.Serializable;
	import java.util.EventListener;

	/**
	* A generic implementation of SingleSelectionModel.
	* <p>
	* <strong>Warning:</strong>
	* Serialized objects of this class will not be compatible with
	* future Swing releases. The current serialization support is
	* appropriate for short term storage or RMI between applications running
	* the same version of Swing. As of 1.4, support for long term storage
	* of all JavaBeans™
	* has been added to the <code>java.beans</code> package.
	* Please see {@link java.beans.XMLEncoder}.
	*
	* @author Dave Moore
	*/
	public class DefaultSingleSelectionModel implements SingleSelectionModel,
	Serializable {
	/* Only one ModelChangeEvent is needed per model instance since the
	* event's only (read-only) state is the source property. The source
	* of events generated here is always "this".
	*/
	protected transient ChangeEvent changeEvent = null;
	/** The collection of registered listeners */
	protected EventListenerList listenerList = new EventListenerList();

	private int index = -1;

	// implements javax.swing.SingleSelectionModel
	public int getSelectedIndex() {
	return index;
	}

	// implements javax.swing.SingleSelectionModel
	public void setSelectedIndex(int index) {
	if (this.index != index) {
	this.index = index;
	fireStateChanged();
	}
	}

	// implements javax.swing.SingleSelectionModel
	public void clearSelection() {
	setSelectedIndex(-1);
	}

	// implements javax.swing.SingleSelectionModel
	public boolean isSelected() {
	boolean ret = false;
	if (getSelectedIndex() != -1) {
	ret = true;
	}
	return ret;
	}

	/**
	* Adds a <code>ChangeListener</code> to the button.
	*/
	public void addChangeListener(ChangeListener l) {
	listenerList.add(ChangeListener.class, l);
	}

	/**
	* Removes a <code>ChangeListener</code> from the button.
	*/
	public void removeChangeListener(ChangeListener l) {
	listenerList.remove(ChangeListener.class, l);
	}

	/**
	* Returns an array of all the change listeners
	* registered on this <code>DefaultSingleSelectionModel</code>.
	*
	* @return all of this model's <code>ChangeListener</code>s
	* or an empty
	* array if no change listeners are currently registered
	*
	* @see #addChangeListener
	* @see #removeChangeListener
	*
	* @since 1.4
	*/
	public ChangeListener[] getChangeListeners() {
	return listenerList.getListeners(ChangeListener.class);
	}

	/**
	* Notifies all listeners that have registered interest for
	* notification on this event type. The event instance
	* is created lazily.
	* @see EventListenerList
	*/
	protected void fireStateChanged() {
	// Guaranteed to return a non-null array
	Object[] listeners = listenerList.getListenerList();
	// Process the listeners last to first, notifying
	// those that are interested in this event
	for (int i = listeners.length-2; i>=0; i-=2) {
	if (listeners[i]==ChangeListener.class) {
	// Lazily create the event:
	if (changeEvent == null)
	changeEvent = new ChangeEvent(this);
	((ChangeListener)listeners[i+1]).stateChanged(changeEvent);
	}
	}
	}

	/**
	* Returns an array of all the objects currently registered as
	* <code><em>Foo</em>Listener</code>s
	* upon this model.
	* <code><em>Foo</em>Listener</code>s
	* are registered using the <code>add<em>Foo</em>Listener</code> method.
	* <p>
	* You can specify the <code>listenerType</code> argument
	* with a class literal, such as <code><em>Foo</em>Listener.class</code>.
	* For example, you can query a <code>DefaultSingleSelectionModel</code>
	* instance <code>m</code>
	* for its change listeners
	* with the following code:
	*
	* <pre>ChangeListener[] cls = (ChangeListener[])(m.getListeners(ChangeListener.class));</pre>
	*
	* If no such listeners exist,
	* this method returns an empty array.
	*
	* @param listenerType the type of listeners requested;
	* this parameter should specify an interface
	* that descends from <code>java.util.EventListener</code>
	* @return an array of all objects registered as
	* <code><em>Foo</em>Listener</code>s
	* on this model,
	* or an empty array if no such
	* listeners have been added
	* @exception ClassCastException if <code>listenerType</code> doesn't
	* specify a class or interface that implements
	* <code>java.util.EventListener</code>
	*
	* @see #getChangeListeners
	*
	* @since 1.3
	*/
	public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
	return listenerList.getListeners(listenerType);
	}
	}

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