001/* AbstractSpinnerModel.java -- 002 Copyright (C) 2004, 2006, Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package javax.swing; 040 041import java.util.EventListener; 042 043import javax.swing.event.ChangeEvent; 044import javax.swing.event.ChangeListener; 045import javax.swing.event.EventListenerList; 046 047/** 048 * Provides standard implementations for some of the methods in 049 * {@link SpinnerModel}. 050 * 051 * @since 1.4 052 * 053 * @author Ka-Hing Cheung 054 */ 055public abstract class AbstractSpinnerModel implements SpinnerModel 056{ 057 private ChangeEvent changeEvent = new ChangeEvent(this); 058 059 /** Stores the listeners registered with the model. */ 060 protected EventListenerList listenerList = new EventListenerList(); 061 062 /** 063 * Creates an <code>AbstractSpinnerModel</code>. 064 */ 065 public AbstractSpinnerModel() 066 { 067 // Nothing to do here. 068 } 069 070 /** 071 * Registers a <code>ChangeListener</code> with the model so that it will 072 * receive {@link ChangeEvent} notifications when the model changes. 073 * 074 * @param listener the listener to add (<code>null</code> is ignored). 075 */ 076 public void addChangeListener(ChangeListener listener) 077 { 078 listenerList.add(ChangeListener.class, listener); 079 } 080 081 /** 082 * Gets all the listeners that are of a particular type. 083 * 084 * @param c the type of listener 085 * @return the listeners that are of the specific type 086 */ 087 public <T extends EventListener> T[] getListeners(Class<T> c) 088 { 089 return listenerList.getListeners(c); 090 } 091 092 /** 093 * Gets all the <code>ChangeListener</code>s. 094 * 095 * @return all the <code>ChangeListener</code>s 096 */ 097 public ChangeListener[] getChangeListeners() 098 { 099 return (ChangeListener[]) listenerList.getListeners(ChangeListener.class); 100 } 101 102 /** 103 * Remove a particular listener. 104 * 105 * @param listener the listener to remove 106 */ 107 public void removeChangeListener(ChangeListener listener) 108 { 109 listenerList.remove(ChangeListener.class, listener); 110 } 111 112 /** 113 * Fires a <code>ChangeEvent</code> to all the <code>ChangeListener</code>s 114 * added to this model 115 */ 116 protected void fireStateChanged() 117 { 118 ChangeListener[] listeners = getChangeListeners(); 119 120 for (int i = 0; i < listeners.length; ++i) 121 listeners[i].stateChanged(changeEvent); 122 } 123}