/*
* Copyright (c) 2000, 2008, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
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*
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*/
package javax.swing;
import java.util.*;
import javax.swing.event.*;
import java.io.
Serializable;
/**
* This class provides the ChangeListener part of the
* SpinnerModel interface that should be suitable for most concrete SpinnerModel
* implementations. Subclasses must provide an implementation of the
* <code>setValue</code>, <code>getValue</code>, <code>getNextValue</code> and
* <code>getPreviousValue</code> methods.
*
* @see JSpinner
* @see SpinnerModel
* @see SpinnerListModel
* @see SpinnerNumberModel
* @see SpinnerDateModel
*
* @author Hans Muller
* @since 1.4
*/
public abstract class
AbstractSpinnerModel implements
SpinnerModel,
Serializable
{
/**
* Only one ChangeEvent 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".
*/
private transient
ChangeEvent changeEvent = null;
/**
* The list of ChangeListeners for this model. Subclasses may
* store their own listeners here.
*/
protected
EventListenerList listenerList = new
EventListenerList();
/**
* Adds a ChangeListener to the model's listener list. The
* ChangeListeners must be notified when the models value changes.
*
* @param l the ChangeListener to add
* @see #removeChangeListener
* @see SpinnerModel#addChangeListener
*/
public void
addChangeListener(
ChangeListener l) {
listenerList.
add(
ChangeListener.class,
l);
}
/**
* Removes a ChangeListener from the model's listener list.
*
* @param l the ChangeListener to remove
* @see #addChangeListener
* @see SpinnerModel#removeChangeListener
*/
public void
removeChangeListener(
ChangeListener l) {
listenerList.
remove(
ChangeListener.class,
l);
}
/**
* Returns an array of all the <code>ChangeListener</code>s added
* to this AbstractSpinnerModel with addChangeListener().
*
* @return all of the <code>ChangeListener</code>s added or an empty
* array if no listeners have been added
* @since 1.4
*/
public
ChangeListener[]
getChangeListeners() {
return
listenerList.
getListeners(
ChangeListener.class);
}
/**
* Run each ChangeListeners stateChanged() method.
*
* @see #setValue
* @see EventListenerList
*/
protected void
fireStateChanged()
{
Object[]
listeners =
listenerList.
getListenerList();
for (int
i =
listeners.length - 2;
i >= 0;
i -=2 ) {
if (
listeners[
i] ==
ChangeListener.class) {
if (
changeEvent == null) {
changeEvent = new
ChangeEvent(this);
}
((
ChangeListener)
listeners[
i+1]).
stateChanged(
changeEvent);
}
}
}
/**
* Return an array of all the listeners of the given type that
* were added to this model. For example to find all of the
* ChangeListeners added to this model:
* <pre>
* myAbstractSpinnerModel.getListeners(ChangeListener.class);
* </pre>
*
* @param listenerType the type of listeners to return, e.g. ChangeListener.class
* @return all of the objects receiving <em>listenerType</em> notifications
* from this model
*/
public <T extends
EventListener> T[]
getListeners(
Class<T>
listenerType) {
return
listenerList.
getListeners(
listenerType);
}
}