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.Graphics; 28 import java.awt.Image; 29 import java.util.stream.Collectors; 30 import sun.awt.image.MultiResolutionToolkitImage; 31 32 /** 33 * This class provides default implementations of several {@code Image} methods 34 * for classes that want to implement the {@MultiResolutionImage} interface. 35 * 36 * For example, 37 * <pre> {@code 38 * public class CustomMultiResolutionImage extends AbstractMultiResolutionImage { 39 * 40 * final Image[] resolutionVariants; 41 * 42 * public CustomMultiResolutionImage(Image... resolutionVariants) { 43 * this.resolutionVariants = resolutionVariants; 44 * } 45 * 46 * public Image getResolutionVariant( 47 * double destImageWidth, double destImageHeight) { 48 * // return a resolution variant based on the given destination image size 49 * } 50 * 51 * public List<Image> getResolutionVariants() { 52 * return Collections.unmodifiableList(Arrays.asList(resolutionVariants)); 53 * } 54 * 55 * protected Image getBaseImage() { 56 * return resolutionVariants[0]; 57 * } 58 * } 59 * } </pre> 60 * 61 * @see java.awt.Image 62 * @see java.awt.image.MultiResolutionImage 63 * 64 * @since 9 65 */ 66 public abstract class AbstractMultiResolutionImage extends java.awt.Image 67 implements MultiResolutionImage { 68 69 @Override 70 public int getWidth(ImageObserver observer) { 71 return getBaseImage().getWidth(observer); 72 } 73 74 @Override 75 public int getHeight(ImageObserver observer) { 76 return getBaseImage().getHeight(observer); 77 } 78 79 @Override 80 public ImageProducer getSource() { 81 Image baseImage = getBaseImage(); 82 int baseWidth = baseImage.getWidth(null); 83 int baseHeight = baseImage.getHeight(null); 84 85 return new MultiResolutionToolkitImage.MultiResolutionImageProducer( 86 getResolutionVariants().stream() 87 .map(rvImage -> new ResolutionVariantItem<>( 88 rvImage.getSource(), 89 rvImage.getWidth(null) / baseWidth, 90 rvImage.getHeight(null) / baseHeight)) 91 .collect(Collectors.toList())); 92 } 93 94 @Override 95 public Graphics getGraphics() { 96 throw new UnsupportedOperationException("getGraphics() not supported" 97 + " on Multi-Resolution Images"); 98 } 99 100 @Override 101 public Object getProperty(String name, ImageObserver observer) { 102 return getBaseImage().getProperty(name, observer); 103 } 104 105 /** 106 * Return the base image representing the best version of the image for 107 * rendering at the default width and height. 108 * 109 * @return the base image of the set of multi-resolution images 110 * 111 * @since 9 112 */ 113 protected abstract Image getBaseImage(); 114 }