/*
* Copyright (c) 1997, 2004, 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<sup><font size="-2">TM</font></sup>
* 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 (ChangeListener[])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);
}
}