/* * Copyright (c) 2000, 2008, 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 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 * setValue, getValue, getNextValue and * getPreviousValue 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 ChangeListeners added * to this AbstractSpinnerModel with addChangeListener(). * * @return all of the ChangeListeners 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: *
     * myAbstractSpinnerModel.getListeners(ChangeListener.class);
     * 
* * @param listenerType the type of listeners to return, e.g. ChangeListener.class * @return all of the objects receiving listenerType notifications * from this model */ public T[] getListeners(Class listenerType) { return listenerList.getListeners(listenerType); } }