1/*
2 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.imageio.plugins.png;
27
28import java.io.IOException;
29import java.util.Locale;
30import java.util.Iterator;
31import javax.imageio.ImageReader;
32import javax.imageio.spi.ImageReaderSpi;
33import javax.imageio.metadata.IIOMetadataFormat;
34import javax.imageio.metadata.IIOMetadataFormatImpl;
35import javax.imageio.stream.ImageInputStream;
36
37public class PNGImageReaderSpi extends ImageReaderSpi {
38
39    private static final String vendorName = "Oracle Corporation";
40
41    private static final String version = "1.0";
42
43    private static final String[] names = { "png", "PNG" };
44
45    private static final String[] suffixes = { "png" };
46
47    private static final String[] MIMETypes = { "image/png", "image/x-png" };
48
49    private static final String readerClassName =
50        "com.sun.imageio.plugins.png.PNGImageReader";
51
52    private static final String[] writerSpiNames = {
53        "com.sun.imageio.plugins.png.PNGImageWriterSpi"
54    };
55
56    public PNGImageReaderSpi() {
57        super(vendorName,
58              version,
59              names,
60              suffixes,
61              MIMETypes,
62              readerClassName,
63              new Class<?>[] { ImageInputStream.class },
64              writerSpiNames,
65              false,
66              null, null,
67              null, null,
68              true,
69              PNGMetadata.nativeMetadataFormatName,
70              "com.sun.imageio.plugins.png.PNGMetadataFormat",
71              null, null
72              );
73    }
74
75    public String getDescription(Locale locale) {
76        return "Standard PNG image reader";
77    }
78
79    public boolean canDecodeInput(Object input) throws IOException {
80        if (!(input instanceof ImageInputStream)) {
81            return false;
82        }
83
84        ImageInputStream stream = (ImageInputStream)input;
85        byte[] b = new byte[8];
86        stream.mark();
87        stream.readFully(b);
88        stream.reset();
89
90        return (b[0] == (byte)137 &&
91                b[1] == (byte)80 &&
92                b[2] == (byte)78 &&
93                b[3] == (byte)71 &&
94                b[4] == (byte)13 &&
95                b[5] == (byte)10 &&
96                b[6] == (byte)26 &&
97                b[7] == (byte)10);
98    }
99
100    public ImageReader createReaderInstance(Object extension) {
101        return new PNGImageReader(this);
102    }
103}
104