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 6 * under the terms of the GNU General Public License version 2 only, as 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 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.awt.image; 26 27 import java.awt.Image; 28 import java.util.List; 29 import java.util.Arrays; 30 import java.util.Collections; 31 import java.util.Objects; 32 33 /** 34 * This class is an array-based implementation of 35 * the {@code AbstractMultiResolutionImage} class. 36 * 37 * This class will implement the 38 * {@code getResolutionVariant(double destImageWidth, double destImageHeight)} 39 * method using a simple algorithm which will return the first image variant 40 * in the array that is large enough to satisfy the rendering request. The 41 * last image in the array will be returned if no suitable image is found 42 * that is as large as the rendering request. 43 * <p> 44 * For best effect the array of images should be sorted with each image being 45 * both wider and taller than the previous image. The base image need not be 46 * the first image in the array. No exception will be thrown if the images 47 * are not sorted as suggested. 48 * 49 * @see java.awt.Image 50 * @see java.awt.image.MultiResolutionImage 51 * @see java.awt.image.AbstractMultiResolutionImage 52 * 53 * @since 1.9 54 */ 55 public class BaseMultiResolutionImage extends AbstractMultiResolutionImage { 56 57 private final int baseImageIndex; 58 private final Image[] resolutionVariants; 59 60 /** 61 * Creates a multi-resolution image with the given resolution variants. 62 * The first resolution variant is used as the base image. 63 * 64 * @param resolutionVariants array of resolution variants sorted by image size 65 * @throws IllegalArgumentException if null or zero-length array is passed 66 * @throws NullPointerException if the specified {@code resolutionVariants} 67 * contains one or more null elements 68 * 69 * @since 1.9 70 */ 71 public BaseMultiResolutionImage(Image... resolutionVariants) { 72 this(0, resolutionVariants); 73 } 74 75 /** 76 * Creates a multi-resolution image with the given base image index and 77 * resolution variants. 78 * 79 * @param baseImageIndex the index of base image in the resolution variants 80 * array 81 * @param resolutionVariants array of resolution variants sorted by image size 82 * @throws IllegalArgumentException if null or zero-length array is passed 83 * @throws NullPointerException if the specified {@code resolutionVariants} 84 * contains one or more null elements 85 * @throws IndexOutOfBoundsException if {@code baseImageIndex} is 86 * negative or greater than or equal to {@code resolutionVariants} 87 * length. 88 * 89 * @since 1.9 90 */ 91 public BaseMultiResolutionImage(int baseImageIndex, 92 Image... resolutionVariants) { 93 94 if (resolutionVariants == null || resolutionVariants.length == 0) { 95 throw new IllegalArgumentException( 96 "Null or zero-length array is passed"); 97 } 98 99 if (baseImageIndex < 0 || baseImageIndex >= resolutionVariants.length) { 100 throw new IndexOutOfBoundsException("Invalid base image index: " 101 + baseImageIndex); 102 } 103 104 this.baseImageIndex = baseImageIndex; 105 this.resolutionVariants = Arrays.copyOf(resolutionVariants, 106 resolutionVariants.length); 107 108 for (Image resolutionVariant : this.resolutionVariants) { 109 Objects.requireNonNull(resolutionVariant, 110 "Resolution variant can't be null"); 111 } 112 } 113 114 @Override 115 public Image getResolutionVariant(double destImageWidth, 116 double destImageHeight) { 117 118 checkSize(destImageWidth, destImageHeight); 119 120 for (Image rvImage : resolutionVariants) { 121 if (destImageWidth <= rvImage.getWidth(null) 122 && destImageHeight <= rvImage.getHeight(null)) { 123 return rvImage; 124 } 125 } 126 return resolutionVariants[resolutionVariants.length - 1]; 127 } 128 129 private static void checkSize(double width, double height) { 130 if (width <= 0 || height <= 0) { 131 throw new IllegalArgumentException(String.format( 132 "Width (%s) or height (%s) cannot be <= 0", width, height)); 133 } 134 135 if (!Double.isFinite(width) || !Double.isFinite(height)) { 136 throw new IllegalArgumentException(String.format( 137 "Width (%s) or height (%s) is not finite", width, height)); 138 } 139 } 140 141 @Override 142 public List<Image> getResolutionVariants() { 143 return Collections.unmodifiableList(Arrays.asList(resolutionVariants)); 144 } 145 146 @Override 147 protected Image getBaseImage() { 148 return resolutionVariants[baseImageIndex]; 149 }