001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * ------------------------
028 * ImageEncoderFactory.java
029 * ------------------------
030 * (C) Copyright 2004-2008, by Richard Atkinson and Contributors.
031 *
032 * Original Author: Richard Atkinson;
033 * Contributor(s): David Gilbert (for Object Refinery Limited);
034 *
035 * Changes
036 * -------
037 * 01-Aug-2004 : Initial version (RA);
038 * 01-Nov-2005 : Now using ImageIO for JPEG encoding, so we no longer have a
039 * dependency on com.sun.* which isn't available on all
040 * implementations (DG);
041 * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
042 *
043 */
044
045 package org.jfree.chart.encoders;
046
047 import java.util.Hashtable;
048
049 /**
050 * Factory class for returning {@link ImageEncoder}s for different
051 * {@link ImageFormat}s.
052 */
053 public class ImageEncoderFactory {
054
055 /** Storage for the encoders. */
056 private static Hashtable encoders = null;
057
058 static {
059 init();
060 }
061
062 /**
063 * Sets up default encoders (uses Sun PNG Encoder if JDK 1.4+ and the
064 * SunPNGEncoderAdapter class is available).
065 */
066 private static void init() {
067 encoders = new Hashtable();
068 encoders.put("jpeg", "org.jfree.chart.encoders.SunJPEGEncoderAdapter");
069 try {
070 // Test for being run under JDK 1.4+
071 Class.forName("javax.imageio.ImageIO");
072 // Test for JFreeChart being compiled under JDK 1.4+
073 Class.forName("org.jfree.chart.encoders.SunPNGEncoderAdapter");
074 encoders.put("png",
075 "org.jfree.chart.encoders.SunPNGEncoderAdapter");
076 encoders.put("jpeg",
077 "org.jfree.chart.encoders.SunJPEGEncoderAdapter");
078 }
079 catch (ClassNotFoundException e) {
080 encoders.put("png",
081 "org.jfree.chart.encoders.KeypointPNGEncoderAdapter");
082 }
083 }
084
085 /**
086 * Used to set additional encoders or replace default ones.
087 *
088 * @param format The image format name.
089 * @param imageEncoderClassName The name of the ImageEncoder class.
090 */
091 public static void setImageEncoder(String format,
092 String imageEncoderClassName) {
093 encoders.put(format, imageEncoderClassName);
094 }
095
096 /**
097 * Used to retrieve an ImageEncoder for a specific image format.
098 *
099 * @param format The image format required.
100 *
101 * @return The ImageEncoder or <code>null</code> if none available.
102 */
103 public static ImageEncoder newInstance(String format) {
104 ImageEncoder imageEncoder = null;
105 String className = (String) encoders.get(format);
106 if (className == null) {
107 throw new IllegalArgumentException("Unsupported image format - "
108 + format);
109 }
110 try {
111 Class imageEncoderClass = Class.forName(className);
112 imageEncoder = (ImageEncoder) imageEncoderClass.newInstance();
113 }
114 catch (Exception e) {
115 throw new IllegalArgumentException(e.toString());
116 }
117 return imageEncoder;
118 }
119
120 /**
121 * Used to retrieve an ImageEncoder for a specific image format.
122 *
123 * @param format The image format required.
124 * @param quality The quality to be set before returning.
125 *
126 * @return The ImageEncoder or <code>null</code> if none available.
127 */
128 public static ImageEncoder newInstance(String format, float quality) {
129 ImageEncoder imageEncoder = newInstance(format);
130 imageEncoder.setQuality(quality);
131 return imageEncoder;
132 }
133
134 /**
135 * Used to retrieve an ImageEncoder for a specific image format.
136 *
137 * @param format The image format required.
138 * @param encodingAlpha Sets whether alpha transparency should be encoded.
139 *
140 * @return The ImageEncoder or <code>null</code> if none available.
141 */
142 public static ImageEncoder newInstance(String format,
143 boolean encodingAlpha) {
144 ImageEncoder imageEncoder = newInstance(format);
145 imageEncoder.setEncodingAlpha(encodingAlpha);
146 return imageEncoder;
147 }
148
149 /**
150 * Used to retrieve an ImageEncoder for a specific image format.
151 *
152 * @param format The image format required.
153 * @param quality The quality to be set before returning.
154 * @param encodingAlpha Sets whether alpha transparency should be encoded.
155 *
156 * @return The ImageEncoder or <code>null</code> if none available.
157 */
158 public static ImageEncoder newInstance(String format, float quality,
159 boolean encodingAlpha) {
160 ImageEncoder imageEncoder = newInstance(format);
161 imageEncoder.setQuality(quality);
162 imageEncoder.setEncodingAlpha(encodingAlpha);
163 return imageEncoder;
164 }
165
166 }