/*
* @(#)AbstractListModel.java 1.34 04/05/05
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.swing;
import javax.swing.event.*;
import java.io.Serializable;
import java.util.EventListener;
/**
* The abstract definition for the data model that provides
* a <code>List</code> with its contents.
* <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}.
*
* @version 1.34 05/05/04
* @author Hans Muller
*/
public abstract class AbstractListModel implements ListModel, Serializable
{
protected EventListenerList listenerList = new EventListenerList();
/**
* Adds a listener to the list that's notified each time a change
* to the data model occurs.
*
* @param l the <code>ListDataListener</code> to be added
*/
public void addListDataListener(ListDataListener l) {
listenerList.add(ListDataListener.class, l);
}
/**
* Removes a listener from the list that's notified each time a
* change to the data model occurs.
*
* @param l the <code>ListDataListener</code> to be removed
*/
public void removeListDataListener(ListDataListener l) {
listenerList.remove(ListDataListener.class, l);
}
/**
* Returns an array of all the list data listeners
* registered on this <code>AbstractListModel</code>.
*
* @return all of this model's <code>ListDataListener</code>s,
* or an empty array if no list data listeners
* are currently registered
*
* @see #addListDataListener
* @see #removeListDataListener
*
* @since 1.4
*/
public ListDataListener[] getListDataListeners() {
return (ListDataListener[])listenerList.getListeners(
ListDataListener.class);
}
/**
* <code>AbstractListModel</code> subclasses must call this method
* <b>after</b>
* one or more elements of the list change. The changed elements
* are specified by the closed interval index0, index1 -- the endpoints
* are included. Note that
* index0 need not be less than or equal to index1.
*
* @param source the <code>ListModel</code> that changed, typically "this"
* @param index0 one end of the new interval
* @param index1 the other end of the new interval
* @see EventListenerList
* @see DefaultListModel
*/
protected void fireContentsChanged(Object source, int index0, int index1)
{
Object[] listeners = listenerList.getListenerList();
ListDataEvent e = null;
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == ListDataListener.class) {
if (e == null) {
e = new ListDataEvent(source, ListDataEvent.CONTENTS_CHANGED, index0, index1);
}
((ListDataListener)listeners[i+1]).contentsChanged(e);
}
}
}
/**
* <code>AbstractListModel</code> subclasses must call this method
* <b>after</b>
* one or more elements are added to the model. The new elements
* are specified by a closed interval index0, index1 -- the enpoints
* are included. Note that
* index0 need not be less than or equal to index1.
*
* @param source the <code>ListModel</code> that changed, typically "this"
* @param index0 one end of the new interval
* @param index1 the other end of the new interval
* @see EventListenerList
* @see DefaultListModel
*/
protected void fireIntervalAdded(Object source, int index0, int index1)
{
Object[] listeners = listenerList.getListenerList();
ListDataEvent e = null;
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == ListDataListener.class) {
if (e == null) {
e = new ListDataEvent(source, ListDataEvent.INTERVAL_ADDED, index0, index1);
}
((ListDataListener)listeners[i+1]).intervalAdded(e);
}
}
}
/**
* <code>AbstractListModel</code> subclasses must call this method
* <b>after</b> one or more elements are removed from the model.
* <code>index0</code> and <code>index1</code> are the end points
* of the interval that's been removed. Note that <code>index0</code>
* need not be less than or equal to <code>index1</code>.
*
* @param source the <code>ListModel</code> that changed, typically "this"
* @param index0 one end of the removed interval,
* including <code>index0</code>
* @param index1 the other end of the removed interval,
* including <code>index1</code>
* @see EventListenerList
* @see DefaultListModel
*/
protected void fireIntervalRemoved(Object source, int index0, int index1)
{
Object[] listeners = listenerList.getListenerList();
ListDataEvent e = null;
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == ListDataListener.class) {
if (e == null) {
e = new ListDataEvent(source, ListDataEvent.INTERVAL_REMOVED, index0, index1);
}
((ListDataListener)listeners[i+1]).intervalRemoved(e);
}
}
}
/**
* 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 list model
* <code>m</code>
* for its list data listeners
* with the following code:
*
* <pre>ListDataListener[] ldls = (ListDataListener[])(m.getListeners(ListDataListener.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 #getListDataListeners
*
* @since 1.3
*/
public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
return listenerList.getListeners(listenerType);
}
}
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