001: /*
002: * $RCSfile: CLibPNGImageReaderSpi.java,v $
003: *
004: *
005: * Copyright (c) 2005 Sun Microsystems, Inc. All Rights Reserved.
006: *
007: * Redistribution and use in source and binary forms, with or without
008: * modification, are permitted provided that the following conditions
009: * are met:
010: *
011: * - Redistribution of source code must retain the above copyright
012: * notice, this list of conditions and the following disclaimer.
013: *
014: * - Redistribution in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * Neither the name of Sun Microsystems, Inc. or the names of
020: * contributors may be used to endorse or promote products derived
021: * from this software without specific prior written permission.
022: *
023: * This software is provided "AS IS," without a warranty of any
024: * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
025: * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
026: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
027: * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
028: * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
029: * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
030: * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
031: * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
032: * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
033: * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
034: * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
035: * POSSIBILITY OF SUCH DAMAGES.
036: *
037: * You acknowledge that this software is not designed or intended for
038: * use in the design, construction, operation or maintenance of any
039: * nuclear facility.
040: *
041: * $Revision: 1.2 $
042: * $Date: 2006/03/31 19:43:40 $
043: * $State: Exp $
044: */
045: package com.sun.media.imageioimpl.plugins.png;
046:
047: import java.util.List;
048: import java.util.Locale;
049: import javax.imageio.spi.ImageReaderSpi;
050: import javax.imageio.stream.ImageInputStream;
051: import javax.imageio.spi.ServiceRegistry;
052: import java.io.IOException;
053: import javax.imageio.ImageReader;
054: import javax.imageio.IIOException;
055: import com.sun.media.imageioimpl.common.PackageUtil;
056: import com.sun.media.imageioimpl.common.ImageUtil;
057:
058: public class CLibPNGImageReaderSpi extends ImageReaderSpi {
059:
060: private static final String[] names = { "png", "PNG" };
061:
062: private static final String[] suffixes = { "png" };
063:
064: private static final String[] MIMETypes = { "image/png",
065: "image/x-png" };
066:
067: private static final String readerClassName = "com.sun.media.imageioimpl.plugins.png.CLibPNGImageReader";
068:
069: private static final String[] writerSpiNames = { "com.sun.media.imageioimpl.plugins.png.CLibPNGImageWriterSpi" };
070:
071: private boolean registered = false;
072:
073: public CLibPNGImageReaderSpi() {
074: super (
075: PackageUtil.getVendor(),
076: PackageUtil.getVersion(),
077: names,
078: suffixes,
079: MIMETypes,
080: readerClassName,
081: STANDARD_INPUT_TYPE,
082: writerSpiNames,
083: false,
084: null,
085: null,
086: null,
087: null,
088: true,
089: CLibPNGMetadata.nativeMetadataFormatName,
090: "com.sun.media.imageioimpl.plugins.png.CLibPNGMetadataFormat",
091: null, null);
092: }
093:
094: public void onRegistration(ServiceRegistry registry, Class category) {
095: if (registered) {
096: return;
097: }
098:
099: registered = true;
100:
101: // Branch as a function of codecLib availability.
102: if (!PackageUtil.isCodecLibAvailable()) {
103: // Deregister provider.
104: registry.deregisterServiceProvider(this );
105: } else {
106:
107: List list = ImageUtil.getJDKImageReaderWriterSPI(registry,
108: "PNG", true);
109:
110: for (int i = 0; i < list.size(); i++) {
111: // Set pairwise ordering to give codecLib reader precedence
112: // over Sun core J2SE reader.
113: registry.setOrdering(category, this , list.get(i));
114: }
115: }
116: }
117:
118: public String getDescription(Locale locale) {
119: String desc = PackageUtil.getSpecificationTitle()
120: + " natively-accelerated PNG Image Reader";
121: return desc;
122: }
123:
124: public boolean canDecodeInput(Object source) throws IOException {
125: if (!(source instanceof ImageInputStream)) {
126: return false;
127: }
128:
129: ImageInputStream stream = (ImageInputStream) source;
130: byte[] b = new byte[8];
131: stream.mark();
132: stream.readFully(b);
133: stream.reset();
134:
135: return (b[0] == (byte) 137 && b[1] == (byte) 80
136: && b[2] == (byte) 78 && b[3] == (byte) 71
137: && b[4] == (byte) 13 && b[5] == (byte) 10
138: && b[6] == (byte) 26 && b[7] == (byte) 10);
139: }
140:
141: public ImageReader createReaderInstance(Object extension)
142: throws IIOException {
143: return new CLibPNGImageReader(this);
144: }
145: }
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