/*

 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.sun.imageio.plugins.png;

import java.io.IOException;

import java.util.Locale;

import java.util.Iterator;

import javax.imageio.ImageReader;

import javax.imageio.spi.ImageReaderSpi;

import javax.imageio.metadata.IIOMetadataFormat;

import javax.imageio.metadata.IIOMetadataFormatImpl;

import javax.imageio.stream.ImageInputStream;

public class PNGImageReaderSpi extends ImageReaderSpi {

    private static final String vendorName = "Oracle Corporation";

    private static final String version = "1.0";

    private static final String[] names = { "png", "PNG" };

    private static final String[] suffixes = { "png" };

    private static final String[] MIMETypes = { "image/png", "image/x-png" };

    private static final String readerClassName =

        "com.sun.imageio.plugins.png.PNGImageReader";

    private static final String[] writerSpiNames = {

        "com.sun.imageio.plugins.png.PNGImageWriterSpi"

    };

    public PNGImageReaderSpi() {

        super(vendorName,

              version,

              names,

              suffixes,

              MIMETypes,

              readerClassName,

              new Class[] { ImageInputStream.class },

              writerSpiNames,

              false,

              null, null,

              null, null,

              true,

              PNGMetadata.nativeMetadataFormatName,

              "com.sun.imageio.plugins.png.PNGMetadataFormat",

              null, null

              );

    }

    public String getDescription(Locale locale) {

        return "Standard PNG image reader";

    }

    public boolean canDecodeInput(Object input) throws IOException {

        if (!(input instanceof ImageInputStream)) {

            return false;

        }

        ImageInputStream stream = (ImageInputStream)input;

        byte[] b = new byte[8];

        stream.mark();

        stream.readFully(b);

        stream.reset();

        return (b[0] == (byte)137 &&

                b[1] == (byte)80 &&

                b[2] == (byte)78 &&

                b[3] == (byte)71 &&

                b[4] == (byte)13 &&

                b[5] == (byte)10 &&

                b[6] == (byte)26 &&

                b[7] == (byte)10);

    }

    public ImageReader createReaderInstance(Object extension) {

        return new PNGImageReader(this);

    }

}