/*

 * 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.gif;

import java.io.IOException;

import java.util.Locale;

import java.util.Iterator;

import javax.imageio.ImageReader;

import javax.imageio.metadata.IIOMetadataFormat;

import javax.imageio.metadata.IIOMetadataFormatImpl;

import javax.imageio.spi.ImageReaderSpi;

import javax.imageio.stream.ImageInputStream;

public class GIFImageReaderSpi extends ImageReaderSpi {

    private static final String vendorName = "Oracle Corporation";

    private static final String version = "1.0";

    private static final String[] names = { "gif", "GIF" };

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

    private static final String[] MIMETypes = { "image/gif" };

    private static final String readerClassName =

        "com.sun.imageio.plugins.gif.GIFImageReader";

    private static final String[] writerSpiNames = {

        "com.sun.imageio.plugins.gif.GIFImageWriterSpi"

    };

    public GIFImageReaderSpi() {

        super(vendorName,

              version,

              names,

              suffixes,

              MIMETypes,

              readerClassName,

              new Class[] { ImageInputStream.class },

              writerSpiNames,

              true,

              GIFStreamMetadata.nativeMetadataFormatName,

              "com.sun.imageio.plugins.gif.GIFStreamMetadataFormat",

              null, null,

              true,

              GIFImageMetadata.nativeMetadataFormatName,

              "com.sun.imageio.plugins.gif.GIFImageMetadataFormat",

              null, null

              );

    }

    public String getDescription(Locale locale) {

        return "Standard GIF image reader";

    }

    public boolean canDecodeInput(Object input) throws IOException {

        if (!(input instanceof ImageInputStream)) {

            return false;

        }

        ImageInputStream stream = (ImageInputStream)input;

        byte[] b = new byte[6];

        stream.mark();

        stream.readFully(b);

        stream.reset();

        return b[0] == 'G' && b[1] == 'I' && b[2] == 'F' && b[3] == '8' &&

            (b[4] == '7' || b[4] == '9') && b[5] == 'a';

    }

    public ImageReader createReaderInstance(Object extension) {

        return new GIFImageReader(this);

    }

}