/*
 * Copyright (c) 2014, 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 sun.awt.image;

import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.*;

This class provides default implementations for the
MultiResolutionImage interface. The developer needs only
to subclass this abstract class and define the getResolutionVariant,
getResolutionVariants, and getBaseImage methods. For example, 
public class CustomMultiResolutionImage extends AbstractMultiResolutionImage {
    int baseImageIndex;
    Image[] resolutionVariants;
    public CustomMultiResolutionImage(int baseImageIndex,
            Image... resolutionVariants) {
         this.baseImageIndex = baseImageIndex;
         this.resolutionVariants = resolutionVariants;
    }
    @Override
    public Image getResolutionVariant(float logicalDPIX, float logicalDPIY,
            float baseImageWidth, float baseImageHeight,
            float destImageWidth, float destImageHeight) {
        // return a resolution variant based on the given logical DPI,
        // base image size, or destination image size
    }
    @Override
    public List<Image> getResolutionVariants() {
        return Arrays.asList(resolutionVariants);
    }
    protected Image getBaseImage() {
        return resolutionVariants[baseImageIndex];
    }
 }
 
See Also:
Image
MultiResolutionImage/**
 * This class provides default implementations for the
 * <code>MultiResolutionImage</code> interface. The developer needs only
 * to subclass this abstract class and define the <code>getResolutionVariant</code>,
 * <code>getResolutionVariants</code>, and <code>getBaseImage</code> methods.
 *
 *
 * For example,
 * {@code
 * public class CustomMultiResolutionImage extends AbstractMultiResolutionImage {
 *
 *     int baseImageIndex;
 *     Image[] resolutionVariants;
 *
 *     public CustomMultiResolutionImage(int baseImageIndex,
 *             Image... resolutionVariants) {
 *          this.baseImageIndex = baseImageIndex;
 *          this.resolutionVariants = resolutionVariants;
 *     }
 *
 *     @Override
 *     public Image getResolutionVariant(float logicalDPIX, float logicalDPIY,
 *             float baseImageWidth, float baseImageHeight,
 *             float destImageWidth, float destImageHeight) {
 *         // return a resolution variant based on the given logical DPI,
 *         // base image size, or destination image size
 *     }
 *
 *     @Override
 *     public List<Image> getResolutionVariants() {
 *         return Arrays.asList(resolutionVariants);
 *     }
 *
 *     protected Image getBaseImage() {
 *         return resolutionVariants[baseImageIndex];
 *     }
 * }
 * }
 *
 * @see java.awt.Image
 * @see java.awt.image.MultiResolutionImage
 *
 */
public abstract class AbstractMultiResolutionImage extends java.awt.Image
        implements MultiResolutionImage {

    
@inheritDoc
/**
     * @inheritDoc
     */
    @Override
    public int getWidth(ImageObserver observer) {
        return getBaseImage().getWidth(null);
    }

    
@inheritDoc
/**
     * @inheritDoc
     */
    @Override
    public int getHeight(ImageObserver observer) {
        return getBaseImage().getHeight(null);
    }

    
@inheritDoc
/**
     * @inheritDoc
     */
    @Override
    public ImageProducer getSource() {
        return getBaseImage().getSource();
    }

    
@inheritDoc
/**
     * @inheritDoc
     */
    @Override
    public Graphics getGraphics() {
        return getBaseImage().getGraphics();

    }

    
@inheritDoc
/**
     * @inheritDoc
     */
    @Override
    public Object getProperty(String name, ImageObserver observer) {
        return getBaseImage().getProperty(name, observer);
    }

    
Returns:
base image/**
     * @return base image
     */
    protected abstract Image getBaseImage();
}