/*

 * 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.awt.image.ColorModel;

import java.awt.image.IndexColorModel;

import java.awt.image.SampleModel;

import java.util.Locale;

import javax.imageio.ImageWriter;

import javax.imageio.ImageTypeSpecifier;

import javax.imageio.metadata.IIOMetadataFormat;

import javax.imageio.metadata.IIOMetadataFormatImpl;

import javax.imageio.spi.ImageWriterSpi;

import javax.imageio.stream.ImageOutputStream;

public class PNGImageWriterSpi extends ImageWriterSpi {

    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 writerClassName =

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

    private static final String[] readerSpiNames = {

        "com.sun.imageio.plugins.png.PNGImageReaderSpi"

    };

    public PNGImageWriterSpi() {

          super(vendorName,

                version,

                names,

                suffixes,

                MIMETypes,

                writerClassName,

                new Class[] { ImageOutputStream.class },

                readerSpiNames,

                false,

                null, null,

                null, null,

                true,

                PNGMetadata.nativeMetadataFormatName,

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

                null, null

                );

    }

    public boolean canEncodeImage(ImageTypeSpecifier type) {

        SampleModel sampleModel = type.getSampleModel();

        ColorModel colorModel = type.getColorModel();

        // Find the maximum bit depth across all channels

        int[] sampleSize = sampleModel.getSampleSize();

        int bitDepth = sampleSize[0];

        for (int i = 1; i < sampleSize.length; i++) {

            if (sampleSize[i] > bitDepth) {

                bitDepth = sampleSize[i];

            }

        }

        // Ensure bitDepth is between 1 and 16

        if (bitDepth < 1 || bitDepth > 16) {

            return false;

        }

        // Check number of bands, alpha

        int numBands = sampleModel.getNumBands();

        if (numBands < 1 || numBands > 4) {

            return false;

        }

        boolean hasAlpha = colorModel.hasAlpha();

        // Fix 4464413: PNGTransparency reg-test was failing

        // because for IndexColorModels that have alpha,

        // numBands == 1 && hasAlpha == true, thus causing

        // the check below to fail and return false.

        if (colorModel instanceof IndexColorModel) {

            return true;

        }

        if ((numBands == 1 || numBands == 3) && hasAlpha) {

            return false;

        }

        if ((numBands == 2 || numBands == 4) && !hasAlpha) {

            return false;

        }

        return true;

    }

    public String getDescription(Locale locale) {

        return "Standard PNG image writer";

    }

    public ImageWriter createWriterInstance(Object extension) {

        return new PNGImageWriter(this);

    }

}