/*
 * @(#)IIOImage.java	1.22 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.imageio;

import java.awt.image.BufferedImage;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.util.List;
import javax.imageio.metadata.IIOMetadata;

/**
 * A simple container class to aggregate an image, a set of
 * thumbnail (preview) images, and an object representing metadata 
 * associated with the image.
 *
 * <p> The image data may take the form of either a
 * <code>RenderedImage</code>, or a <code>Raster</code>.  Reader
 * methods that return an <code>IIOImage</code> will always return a
 * <code>BufferedImage</code> using the <code>RenderedImage</code>
 * reference.  Writer methods that accept an <code>IIOImage</code>
 * will always accept a <code>RenderedImage</code>, and may optionally
 * accept a <code>Raster</code>.
 *
 * <p> Exactly one of <code>getRenderedImage</code> and
 * <code>getRaster</code> will return a non-<code>null</code> value.
 * Subclasses are responsible for ensuring this behavior. 
 *
 * @see ImageReader#readAll(int, ImageReadParam)
 * @see ImageReader#readAll(java.util.Iterator)
 * @see ImageWriter#write(javax.imageio.metadata.IIOMetadata,
 *                        IIOImage, ImageWriteParam)
 * @see ImageWriter#write(IIOImage)
 * @see ImageWriter#writeToSequence(IIOImage, ImageWriteParam)
 * @see ImageWriter#writeInsert(int, IIOImage, ImageWriteParam)
 *
 * @version 0.5
 */
public class IIOImage {

    /**
     * The <code>RenderedImage</code> being referenced.
     */
    protected RenderedImage image;

    /**
     * The <code>Raster</code> being referenced.
     */
    protected Raster raster;

    /**
     * A <code>List</code> of <code>BufferedImage</code> thumbnails,
     * or <code>null</code>.  Non-<code>BufferedImage</code> objects
     * must not be stored in this <code>List</code>.
     */
    protected List<? extends BufferedImage> thumbnails = null;

    /**
     * An <code>IIOMetadata</code> object containing metadata
     * associated with the image.
     */
    protected IIOMetadata metadata;

    /**
     * Constructs an <code>IIOImage</code> containing a
     * <code>RenderedImage</code>, and thumbnails and metadata
     * associated with it.
     *
     * <p> All parameters are stored by reference.
     *
     * <p> The <code>thumbnails</code> argument must either be
     * <code>null</code> or contain only <code>BufferedImage</code>
     * objects.
     *
     * @param image a <code>RenderedImage</code>.
     * @param thumbnails a <code>List</code> of <code>BufferedImage</code>s,
     * or <code>null</code>.
     * @param metadata an <code>IIOMetadata</code> object, or
     * <code>null</code>.
     *
     * @exception IllegalArgumentException if <code>image</code> is
     * <code>null</code>.
     */
    public IIOImage(RenderedImage image,
                    List<? extends BufferedImage> thumbnails,
                    IIOMetadata metadata) {
        if (image == null) {
            throw new IllegalArgumentException("image == null!");
        }
        this.image = image;
        this.raster = null;
        this.thumbnails = thumbnails;
        this.metadata = metadata;
    }

    /**