/*
* Copyright (c) 2015, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.awt.image;
import java.awt.Graphics;
import java.awt.Image;
/**
* This class provides default implementations of several {@code Image} methods
* for classes that want to implement the {@code MultiResolutionImage}
* interface.
*
* For example,
* <pre> {@code
* public class CustomMultiResolutionImage extends AbstractMultiResolutionImage {
*
* final Image[] resolutionVariants;
*
* public CustomMultiResolutionImage(Image... resolutionVariants) {
* this.resolutionVariants = resolutionVariants;
* }
*
* public Image getResolutionVariant(
* double destImageWidth, double destImageHeight) {
* // return a resolution variant based on the given destination image size
* }
*
* public List<Image> getResolutionVariants() {
* return Collections.unmodifiableList(Arrays.asList(resolutionVariants));
* }
*
* protected Image getBaseImage() {
* return resolutionVariants[0];
* }
* }
* } </pre>
*
* @see java.awt.Image
* @see java.awt.image.MultiResolutionImage
*
* @since 9
*/
public abstract class AbstractMultiResolutionImage extends java.awt.Image
implements MultiResolutionImage {
/**
* This method simply delegates to the same method on the base image and
* it is equivalent to: {@code getBaseImage().getWidth(observer)}.
*
* @return the width of the base image, or -1 if the width is not yet known
* @see #getBaseImage()
*
* @since 9
*/
@Override
public int getWidth(ImageObserver observer) {
return getBaseImage().getWidth(observer);
}
/**
* This method simply delegates to the same method on the base image and
* it is equivalent to: {@code getBaseImage().getHeight(observer)}.
*
* @return the height of the base image, or -1 if the height is not yet known
* @see #getBaseImage()
*
* @since 9
*/
@Override
public int getHeight(ImageObserver observer) {
return getBaseImage().getHeight(observer);
}
/**
* This method simply delegates to the same method on the base image and
* it is equivalent to: {@code getBaseImage().getSource()}.
*
* @return the image producer that produces the pixels for the base image
* @see #getBaseImage()
*
* @since 9
*/
@Override
public ImageProducer getSource() {
return getBaseImage().getSource();
}
/**
* As per the contract of the base {@code Image#getGraphics()} method,
* this implementation will always throw {@code UnsupportedOperationException}
* since only off-screen images can return a {@code Graphics} object.
*
* @return throws {@code UnsupportedOperationException}
* @throws UnsupportedOperationException this method is not supported
*/
@Override
public Graphics getGraphics() {
throw new UnsupportedOperationException("getGraphics() not supported"
+ " on Multi-Resolution Images");
}
/**
* This method simply delegates to the same method on the base image and
* it is equivalent to: {@code getBaseImage().getProperty(name, observer)}.
*
* @return the value of the named property in the base image
/**代码未完, 请加载全部代码(NowJava.com).**/