1/*
2 * Copyright (c) 2015, 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
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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 *
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24 */
25package java.awt.image;
26
27import java.awt.Image;
28import java.util.List;
29
30/**
31 * This interface is designed to be an optional additional API supported by
32 * some implementations of {@link java.awt.Image} to allow them to provide
33 * alternate images for various rendering resolutions. The various
34 * {@code Graphics.drawImage(...)} variant methods will consult the methods
35 * of this interface if it is implemented on the argument {@code Image} object
36 * in order to choose the best representation to use for each rendering operation.
37 * <p>
38 * The {@code MultiResolutionImage} interface should be implemented by any
39 * subclass of {@code java.awt.Image} whose instances are intended to provide
40 * image resolution variants according to the given image width and height.
41 * For convenience, toolkit images obtained from
42 * {@code Toolkit.getImage(String name)} and {@code Toolkit.getImage(URL url)}
43 * will implement this interface on platforms that support naming conventions
44 * for resolution variants of stored image media and the
45 * {@code AbstractMultiResolutionImage} and {@code BaseMultiResolutionImage}
46 * classes are provided to facilitate easy construction of custom multi-resolution
47 * images from a list of related images.
48 *
49 * @see java.awt.Image
50 * @see java.awt.image.AbstractMultiResolutionImage
51 * @see java.awt.image.BaseMultiResolutionImage
52 * @see java.awt.Toolkit#getImage(java.lang.String filename)
53 * @see java.awt.Toolkit#getImage(java.net.URL url)
54 *
55 * @since 9
56 */
57public interface MultiResolutionImage {
58
59    /**
60     * Gets a specific image that is the best variant to represent
61     * this logical image at the indicated size.
62     *
63     * @param destImageWidth the width of the destination image, in pixels.
64     * @param destImageHeight the height of the destination image, in pixels.
65     * @return image resolution variant.
66     * @throws IllegalArgumentException if {@code destImageWidth} or
67     *         {@code destImageHeight} is less than or equal to zero, infinity,
68     *         or NaN.
69     *
70     * @since 9
71     */
72    Image getResolutionVariant(double destImageWidth, double destImageHeight);
73
74    /**
75     * Gets a readable list of all resolution variants.
76     * The list must be nonempty and contain at least one resolution variant.
77     * <p>
78     * Note that many implementations might return an unmodifiable list.
79     *
80     * @return list of resolution variants.
81     * @since 9
82     */
83    public List<Image> getResolutionVariants();
84}
85