001/* =========================================================== 002 * Orson Charts : a 3D chart library for the Java(tm) platform 003 * =========================================================== 004 * 005 * (C)opyright 2013-2016, by Object Refinery Limited. All rights reserved. 006 * 007 * http://www.object-refinery.com/orsoncharts/index.html 008 * 009 * This program is free software: you can redistribute it and/or modify 010 * it under the terms of the GNU General Public License as published by 011 * the Free Software Foundation, either version 3 of the License, or 012 * (at your option) any later version. 013 * 014 * This program is distributed in the hope that it will be useful, 015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 017 * GNU General Public License for more details. 018 * 019 * You should have received a copy of the GNU General Public License 020 * along with this program. If not, see <http://www.gnu.org/licenses/>. 021 * 022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 023 * Other names may be trademarks of their respective owners.] 024 * 025 * If you do not wish to be bound by the terms of the GPL, an alternative 026 * commercial license can be purchased. For details, please see visit the 027 * Orson Charts home page: 028 * 029 * http://www.object-refinery.com/orsoncharts/index.html 030 * 031 */ 032 033package com.orsoncharts.data; 034 035import java.util.Arrays; 036import java.util.EventListener; 037import java.util.List; 038import javax.swing.event.EventListenerList; 039 040/** 041 * A base class that can be used to create new dataset classes. 042 */ 043public class AbstractDataset3D implements Dataset3D { 044 045 /** Storage for registered change listeners. */ 046 private transient EventListenerList listenerList; 047 048 /** 049 * A flag that controls whether or not the dataset will notify listeners 050 * of changes (defaults to {@code true}, but sometimes it is useful 051 * to disable this). 052 */ 053 private boolean notify; 054 055 /** 056 * Default constructor - allocates storage for listeners that can 057 * be registered with the dataset. 058 */ 059 protected AbstractDataset3D() { 060 this.listenerList = new EventListenerList(); 061 } 062 063 /** 064 * Returns a flag that controls whether or not change events are sent to 065 * registered listeners. 066 * 067 * @return A boolean. 068 * 069 * @see #setNotify(boolean) 070 */ 071 public boolean isNotify() { 072 return this.notify; 073 } 074 075 /** 076 * Sets a flag that controls whether or not listeners receive 077 * {@link Dataset3DChangeEvent} notifications. 078 * 079 * @param notify a boolean. 080 * 081 * @see #isNotify() 082 */ 083 public void setNotify(boolean notify) { 084 this.notify = notify; 085 // if the flag is being set to true, there may be queued up changes... 086 if (notify) { 087 fireChangeEvent(); 088 } 089 } 090 091 /** 092 * Registers an object to receive notification of changes to the dataset. 093 * 094 * @param listener the object to register. 095 * 096 * @see #removeChangeListener(Dataset3DChangeListener) 097 */ 098 @Override 099 public void addChangeListener(Dataset3DChangeListener listener) { 100 this.listenerList.add(Dataset3DChangeListener.class, listener); 101 } 102 103 /** 104 * Deregisters an object so that it no longer receives notification of 105 * changes to the dataset. 106 * 107 * @param listener the object to deregister. 108 * 109 * @see #addChangeListener(Dataset3DChangeListener) 110 */ 111 @Override 112 public void removeChangeListener(Dataset3DChangeListener listener) { 113 this.listenerList.remove(Dataset3DChangeListener.class, listener); 114 } 115 116 /** 117 * Returns {@code true} if the specified object is registered with 118 * the dataset as a listener. Most applications won't need to call this 119 * method, it exists mainly for use by unit testing code. 120 * 121 * @param listener the listener. 122 * 123 * @return A boolean. 124 * 125 * @see #addChangeListener(Dataset3DChangeListener) 126 * @see #removeChangeListener(Dataset3DChangeListener) 127 */ 128 @Override 129 public boolean hasListener(EventListener listener) { 130 List<?> list = Arrays.asList(this.listenerList.getListenerList()); 131 return list.contains(listener); 132 } 133 134 /** 135 * Notifies all registered listeners that the dataset has changed. 136 * 137 * @see #addChangeListener(Dataset3DChangeListener) 138 */ 139 protected void fireDatasetChanged() { 140 notifyListeners(new Dataset3DChangeEvent(this, this)); 141 } 142 143 /** 144 * Notifies all registered listeners that the dataset has changed, unless 145 * the {@code notify} flag is set to {@code false} in which 146 * case this method does nothing. 147 * 148 * @param event contains information about the event that triggered the 149 * notification. 150 * 151 * @see #addChangeListener(Dataset3DChangeListener) 152 * @see #removeChangeListener(Dataset3DChangeListener) 153 */ 154 protected void notifyListeners(Dataset3DChangeEvent event) { 155 // if the 'notify' flag has been switched to false, we don't notify 156 // the listeners 157 if (!this.notify) { 158 return; 159 } 160 Object[] listeners = this.listenerList.getListenerList(); 161 for (int i = listeners.length - 2; i >= 0; i -= 2) { 162 if (listeners[i] == Dataset3DChangeListener.class) { 163 ((Dataset3DChangeListener) listeners[i + 1]) 164 .datasetChanged(event); 165 } 166 } 167 } 168 169 /** 170 * Sends a {@link Dataset3DChangeEvent} to all registered listeners, unless 171 * the {@code notify} flag is set to {@code false} in which 172 * case this method does nothing. 173 */ 174 protected void fireChangeEvent() { 175 notifyListeners(new Dataset3DChangeEvent(this, this)); 176 } 177 178}