001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2006, 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     * SunJPEGEncoderAdapter.java
029     * --------------------------
030     * (C) Copyright 2004-2006, by Richard Atkinson and Contributors.
031     *
032     * Original Author:  Richard Atkinson;
033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
034     *
035     * $Id: SunJPEGEncoderAdapter.java,v 1.3.2.3 2006/07/20 14:27:00 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 01-Aug-2004 : Initial version (RA);
040     * 01-Nov-2005 : To remove the dependency on non-supported APIs, use ImageIO 
041     *               instead of com.sun.image.codec.jpeg.JPEGImageEncoder - this 
042     *               adapter will only be available on JDK 1.4 or later (DG);
043     * ------------- JFREECHART 1.0.0 ---------------------------------------------
044     * 20-Jul-2006 : Pass quality setting to ImageIO. Also increased default 
045     *               value to 0.95 (DG);
046     * 
047     */
048    
049    package org.jfree.chart.encoders;
050    
051    import java.awt.image.BufferedImage;
052    import java.io.ByteArrayOutputStream;
053    import java.io.IOException;
054    import java.io.OutputStream;
055    import java.util.Iterator;
056    
057    import javax.imageio.IIOImage;
058    import javax.imageio.ImageIO;
059    import javax.imageio.ImageWriteParam;
060    import javax.imageio.ImageWriter;
061    import javax.imageio.stream.ImageOutputStream;
062    
063    /**
064     * Adapter class for the Sun JPEG Encoder.  The {@link ImageEncoderFactory} 
065     * will only return a reference to this class by default if the library has 
066     * been compiled under a JDK 1.4+ and is being run using a JRE 1.4+.
067     */
068    public class SunJPEGEncoderAdapter implements ImageEncoder {
069        
070        /** The quality setting (in the range 0.0f to 1.0f). */
071        private float quality = 0.95f;
072    
073        /**
074         * Creates a new <code>SunJPEGEncoderAdapter</code> instance.
075         */
076        public SunJPEGEncoderAdapter() {
077        }
078    
079        /**
080         * Returns the quality of the image encoding, which is a number in the
081         * range 0.0f to 1.0f (higher values give better quality output, but larger
082         * file sizes).  The default value is 0.95f.
083         *
084         * @return A float representing the quality, in the range 0.0f to 1.0f.
085         * 
086         * @see #setQuality(float)
087         */
088        public float getQuality() {
089            return this.quality;
090        }
091    
092        /**
093         * Set the quality of the image encoding.
094         *
095         * @param quality  A float representing the quality (in the range 0.0f to
096         *     1.0f).
097         *     
098         * @see #getQuality()
099         */
100        public void setQuality(float quality) {
101            if (quality < 0.0f || quality > 1.0f) {
102                throw new IllegalArgumentException(
103                        "The 'quality' must be in the range 0.0f to 1.0f");
104            }
105            this.quality = quality;
106        }
107    
108        /**
109         * Returns <code>false</code> always, indicating that this encoder does not
110         * encode alpha transparency.
111         *
112         * @return <code>false</code>.
113         */
114        public boolean isEncodingAlpha() {
115            return false;
116        }
117    
118        /**
119         * Set whether the encoder should encode alpha transparency (this is not 
120         * supported for JPEG, so this method does nothing).
121         *
122         * @param encodingAlpha  ignored.
123         */
124        public void setEncodingAlpha(boolean encodingAlpha) {
125            //  No op
126        }
127    
128        /**
129         * Encodes an image in JPEG format.
130         *
131         * @param bufferedImage  the image to be encoded (<code>null</code> not 
132         *     permitted).
133         * 
134         * @return The byte[] that is the encoded image.
135         * 
136         * @throws IOException if there is an I/O problem.
137         * @throws NullPointerException if <code>bufferedImage</code> is 
138         *     <code>null</code>.
139         */
140        public byte[] encode(BufferedImage bufferedImage) throws IOException {
141            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
142            encode(bufferedImage, outputStream);
143            return outputStream.toByteArray();
144        }
145    
146        /**
147         * Encodes an image in JPEG format and writes it to an output stream.
148         *
149         * @param bufferedImage  the image to be encoded (<code>null</code> not 
150         *     permitted).
151         * @param outputStream  the OutputStream to write the encoded image to 
152         *     (<code>null</code> not permitted).
153         * 
154         * @throws IOException if there is an I/O problem.
155         * @throws NullPointerException if <code>bufferedImage</code> is 
156         *     <code>null</code>.
157         */
158        public void encode(BufferedImage bufferedImage, OutputStream outputStream) 
159                throws IOException {
160            if (bufferedImage == null) {
161                throw new IllegalArgumentException("Null 'image' argument.");
162            }
163            if (outputStream == null) {
164                throw new IllegalArgumentException("Null 'outputStream' argument.");
165            }
166            Iterator iterator = ImageIO.getImageWritersByFormatName("jpeg");
167            ImageWriter writer = (ImageWriter) iterator.next();
168            ImageWriteParam p = writer.getDefaultWriteParam();
169            p.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
170            p.setCompressionQuality(this.quality);
171            ImageOutputStream ios = ImageIO.createImageOutputStream(outputStream);
172            writer.setOutput(ios);
173            writer.write(null, new IIOImage(bufferedImage, null, null), p);
174            ios.flush();
175            writer.dispose();
176            ios.close();
177        }
178    
179    }