| /* |
| * Copyright (c) 1995, 2003, 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.Image; |
| import java.awt.image.ImageFilter; |
| import java.awt.image.ImageConsumer; |
| import java.awt.image.ImageProducer; |
| import java.util.Hashtable; |
| import java.awt.image.ColorModel; |
| |
| /** |
| * This class is an implementation of the ImageProducer interface which |
| * takes an existing image and a filter object and uses them to produce |
| * image data for a new filtered version of the original image. |
| * Here is an example which filters an image by swapping the red and |
| * blue compents: |
| * <pre> |
| * |
| * Image src = getImage("doc:///demo/images/duke/T1.gif"); |
| * ImageFilter colorfilter = new RedBlueSwapFilter(); |
| * Image img = createImage(new FilteredImageSource(src.getSource(), |
| * colorfilter)); |
| * |
| * </pre> |
| * |
| * @see ImageProducer |
| * |
| * @author Jim Graham |
| */ |
| public class FilteredImageSource implements ImageProducer { |
| ImageProducer src; |
| ImageFilter filter; |
| |
| /** |
| * Constructs an ImageProducer object from an existing ImageProducer |
| * and a filter object. |
| * @param orig the specified <code>ImageProducer</code> |
| * @param imgf the specified <code>ImageFilter</code> |
| * @see ImageFilter |
| * @see java.awt.Component#createImage |
| */ |
| public FilteredImageSource(ImageProducer orig, ImageFilter imgf) { |
| src = orig; |
| filter = imgf; |
| } |
| |
| private Hashtable proxies; |
| |
| /** |
| * Adds the specified <code>ImageConsumer</code> |
| * to the list of consumers interested in data for the filtered image. |
| * An instance of the original <code>ImageFilter</code> |
| * is created |
| * (using the filter's <code>getFilterInstance</code> method) |
| * to manipulate the image data |
| * for the specified <code>ImageConsumer</code>. |
| * The newly created filter instance |
| * is then passed to the <code>addConsumer</code> method |
| * of the original <code>ImageProducer</code>. |
| * |
| * <p> |
| * This method is public as a side effect |
| * of this class implementing |
| * the <code>ImageProducer</code> interface. |
| * It should not be called from user code, |
| * and its behavior if called from user code is unspecified. |
| * |
| * @param ic the consumer for the filtered image |
| * @see ImageConsumer |
| */ |
| public synchronized void addConsumer(ImageConsumer ic) { |
| if (proxies == null) { |
| proxies = new Hashtable(); |
| } |
| if (!proxies.containsKey(ic)) { |
| ImageFilter imgf = filter.getFilterInstance(ic); |
| proxies.put(ic, imgf); |
| src.addConsumer(imgf); |
| } |
| } |
| |
| /** |
| * Determines whether an ImageConsumer is on the list of consumers |
| * currently interested in data for this image. |
| * |
| * <p> |
| * This method is public as a side effect |
| * of this class implementing |
| * the <code>ImageProducer</code> interface. |
| * It should not be called from user code, |
| * and its behavior if called from user code is unspecified. |
| * |
| * @param ic the specified <code>ImageConsumer</code> |
| * @return true if the ImageConsumer is on the list; false otherwise |
| * @see ImageConsumer |
| */ |
| public synchronized boolean isConsumer(ImageConsumer ic) { |
| return (proxies != null && proxies.containsKey(ic)); |
| } |
| |
| /** |
| * Removes an ImageConsumer from the list of consumers interested in |
| * data for this image. |
| * |
| * <p> |
| * This method is public as a side effect |
| * of this class implementing |
| * the <code>ImageProducer</code> interface. |
| * It should not be called from user code, |
| * and its behavior if called from user code is unspecified. |
| * |
| * @see ImageConsumer |
| */ |
| public synchronized void removeConsumer(ImageConsumer ic) { |
| if (proxies != null) { |
| ImageFilter imgf = (ImageFilter) proxies.get(ic); |
| if (imgf != null) { |
| src.removeConsumer(imgf); |
| proxies.remove(ic); |
| if (proxies.isEmpty()) { |
| proxies = null; |
| } |
| } |
| } |
| } |
| |
| /** |
| * Starts production of the filtered image. |
| * If the specified <code>ImageConsumer</code> |
| * isn't already a consumer of the filtered image, |
| * an instance of the original <code>ImageFilter</code> |
| * is created |
| * (using the filter's <code>getFilterInstance</code> method) |
| * to manipulate the image data |
| * for the <code>ImageConsumer</code>. |
| * The filter instance for the <code>ImageConsumer</code> |
| * is then passed to the <code>startProduction</code> method |
| * of the original <code>ImageProducer</code>. |
| * |
| * <p> |
| * This method is public as a side effect |
| * of this class implementing |
| * the <code>ImageProducer</code> interface. |
| * It should not be called from user code, |
| * and its behavior if called from user code is unspecified. |
| * |
| * @param ic the consumer for the filtered image |
| * @see ImageConsumer |
| */ |
| public void startProduction(ImageConsumer ic) { |
| if (proxies == null) { |
| proxies = new Hashtable(); |
| } |
| ImageFilter imgf = (ImageFilter) proxies.get(ic); |
| if (imgf == null) { |
| imgf = filter.getFilterInstance(ic); |
| proxies.put(ic, imgf); |
| } |
| src.startProduction(imgf); |
| } |
| |
| /** |
| * Requests that a given ImageConsumer have the image data delivered |
| * one more time in top-down, left-right order. The request is |
| * handed to the ImageFilter for further processing, since the |
| * ability to preserve the pixel ordering depends on the filter. |
| * |
| * <p> |
| * This method is public as a side effect |
| * of this class implementing |
| * the <code>ImageProducer</code> interface. |
| * It should not be called from user code, |
| * and its behavior if called from user code is unspecified. |
| * |
| * @see ImageConsumer |
| */ |
| public void requestTopDownLeftRightResend(ImageConsumer ic) { |
| if (proxies != null) { |
| ImageFilter imgf = (ImageFilter) proxies.get(ic); |
| if (imgf != null) { |
| imgf.resendTopDownLeftRight(src); |
| } |
| } |
| } |
| } |
