| /* PNGImageReaderSpi.java -- The ImageReader service provider for PNG |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.imageio.png; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.Locale; |
| |
| import javax.imageio.ImageReader; |
| import javax.imageio.spi.ImageReaderSpi; |
| import javax.imageio.stream.ImageInputStream; |
| |
| /** |
| * The ImageIO ImageReader service provider for PNG images. |
| * |
| * @author Roman Kennke (kennke@aicas.com) |
| */ |
| public class PNGImageReaderSpi |
| extends ImageReaderSpi |
| { |
| |
| /** |
| * The PNG file signature. |
| */ |
| private static final byte[] SIGNATURE = new byte[] |
| { (byte) 137, 80, 78, 71, 13, 10, 26, 10 }; |
| |
| private static final String VENDOR_NAME = "GNU"; |
| static final String VERSION = "1.0"; |
| static final String READER_CLASSNAME = |
| "gnu.javax.imageio.png.PNGImageReader"; |
| static final String[] NAMES = { "Portable Network Graphics" }; |
| static final String[] SUFFIXES = { ".png" , ".PNG" }; |
| static final String[] MIME_TYPES = { "image/png" }; |
| static final String[] WRITER_SPI_NAMES = |
| new String[] { "gnu.javax.imageio.png.PNGWriterSpi" }; |
| static final Class[] INPUT_TYPES = new Class[]{ InputStream.class, |
| ImageInputStream.class}; |
| public PNGImageReaderSpi() |
| { |
| super(VENDOR_NAME, VERSION, NAMES, SUFFIXES, MIME_TYPES, READER_CLASSNAME, |
| INPUT_TYPES, WRITER_SPI_NAMES, false, null, null, null, null, false, |
| null, null, null, null); |
| } |
| |
| /** |
| * Determines if the PNG ImageReader can decode the specified input. |
| * |
| * @param source the source to decode |
| */ |
| public boolean canDecodeInput(Object source) throws IOException |
| { |
| boolean canDecode = false; |
| if (source instanceof ImageInputStream) |
| { |
| ImageInputStream in = (ImageInputStream) source; |
| in.mark(); |
| canDecode = true; |
| for (int i = 0; i < SIGNATURE.length && canDecode; i++) |
| { |
| byte sig = (byte) in.read(); |
| if (sig != SIGNATURE[i]) { |
| canDecode = false; |
| } |
| } |
| in.reset(); |
| } |
| return canDecode; |
| } |
| |
| /** |
| * Returns a new PNGImageReader instance. |
| * |
| * @param extension the extension, ignored |
| */ |
| public ImageReader createReaderInstance(Object extension) |
| throws IOException |
| { |
| return new PNGImageReader(this); |
| } |
| |
| /** |
| * Returns a description. |
| * |
| * @param locale the locale |
| */ |
| public String getDescription(Locale locale) |
| { |
| return "Portable Network Graphics"; |
| } |
| |
| } |