/* |
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* Copyright (c) 1995, 2018, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.awt.image; |
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import java.awt.Image; |
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import java.awt.image.ImageFilter; |
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import java.awt.image.ImageConsumer; |
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import java.awt.image.ImageProducer; |
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import java.util.Hashtable; |
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import java.awt.image.ColorModel; |
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/** |
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* This class is an implementation of the ImageProducer interface which |
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* takes an existing image and a filter object and uses them to produce |
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* image data for a new filtered version of the original image. |
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* Here is an example which filters an image by swapping the red and |
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* blue compents: |
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* <pre> |
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* |
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* Image src = getImage("doc:///demo/images/duke/T1.gif"); |
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* ImageFilter colorfilter = new RedBlueSwapFilter(); |
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* Image img = createImage(new FilteredImageSource(src.getSource(), |
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* colorfilter)); |
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* |
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* </pre> |
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* |
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* @see ImageProducer |
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* |
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* @author Jim Graham |
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*/ |
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public class FilteredImageSource implements ImageProducer { |
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ImageProducer src; |
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ImageFilter filter; |
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/** |
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* Constructs an ImageProducer object from an existing ImageProducer |
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* and a filter object. |
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* @param orig the specified <code>ImageProducer</code> |
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* @param imgf the specified <code>ImageFilter</code> |
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* @see ImageFilter |
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* @see java.awt.Component#createImage |
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*/ |
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public FilteredImageSource(ImageProducer orig, ImageFilter imgf) { |
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src = orig; |
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filter = imgf; |
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} |
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private Hashtable proxies; |
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/** |
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* Adds the specified <code>ImageConsumer</code> |
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* to the list of consumers interested in data for the filtered image. |
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* An instance of the original <code>ImageFilter</code> |
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* is created |
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* (using the filter's <code>getFilterInstance</code> method) |
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* to manipulate the image data |
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* for the specified <code>ImageConsumer</code>. |
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* The newly created filter instance |
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* is then passed to the <code>addConsumer</code> method |
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* of the original <code>ImageProducer</code>. |
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* |
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* <p> |
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* This method is public as a side effect |
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* of this class implementing |
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* the <code>ImageProducer</code> interface. |
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* It should not be called from user code, |
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* and its behavior if called from user code is unspecified. |
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* |
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* @param ic the consumer for the filtered image |
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* @see ImageConsumer |
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*/ |
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public synchronized void addConsumer(ImageConsumer ic) { |
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if (proxies == null) { |
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proxies = new Hashtable(); |
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} |
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if (!proxies.containsKey(ic)) { |
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ImageFilter imgf = filter.getFilterInstance(ic); |
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proxies.put(ic, imgf); |
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src.addConsumer(imgf); |
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} |
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} |
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/** |
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* Determines whether an ImageConsumer is on the list of consumers |
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* currently interested in data for this image. |
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* |
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* <p> |
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* This method is public as a side effect |
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* of this class implementing |
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* the <code>ImageProducer</code> interface. |
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* It should not be called from user code, |
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* and its behavior if called from user code is unspecified. |
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* |
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* @param ic the specified <code>ImageConsumer</code> |
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* @return true if the ImageConsumer is on the list; false otherwise |
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* @see ImageConsumer |
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*/ |
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public synchronized boolean isConsumer(ImageConsumer ic) { |
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return (proxies != null && proxies.containsKey(ic)); |
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} |
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/** |
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* Removes an ImageConsumer from the list of consumers interested in |
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* data for this image. |
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* |
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* <p> |
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* This method is public as a side effect |
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* of this class implementing |
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* the <code>ImageProducer</code> interface. |
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* It should not be called from user code, |
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* and its behavior if called from user code is unspecified. |
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* |
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* @see ImageConsumer |
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*/ |
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public synchronized void removeConsumer(ImageConsumer ic) { |
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if (proxies != null) { |
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ImageFilter imgf = (ImageFilter) proxies.get(ic); |
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if (imgf != null) { |
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src.removeConsumer(imgf); |
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proxies.remove(ic); |
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if (proxies.isEmpty()) { |
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proxies = null; |
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} |
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} |
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} |
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} |
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/** |
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* Starts production of the filtered image. |
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* If the specified <code>ImageConsumer</code> |
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* isn't already a consumer of the filtered image, |
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* an instance of the original <code>ImageFilter</code> |
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* is created |
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* (using the filter's <code>getFilterInstance</code> method) |
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* to manipulate the image data |
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* for the <code>ImageConsumer</code>. |
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* The filter instance for the <code>ImageConsumer</code> |
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* is then passed to the <code>startProduction</code> method |
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* of the original <code>ImageProducer</code>. |
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* |
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* <p> |
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* This method is public as a side effect |
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* of this class implementing |
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* the <code>ImageProducer</code> interface. |
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* It should not be called from user code, |
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* and its behavior if called from user code is unspecified. |
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* |
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* @param ic the consumer for the filtered image |
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* @see ImageConsumer |
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*/ |
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public synchronized void startProduction(ImageConsumer ic) { |
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if (proxies == null) { |
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proxies = new Hashtable(); |
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} |
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ImageFilter imgf = (ImageFilter) proxies.get(ic); |
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if (imgf == null) { |
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imgf = filter.getFilterInstance(ic); |
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proxies.put(ic, imgf); |
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} |
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src.startProduction(imgf); |
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} |
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/** |
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* Requests that a given ImageConsumer have the image data delivered |
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* one more time in top-down, left-right order. The request is |
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* handed to the ImageFilter for further processing, since the |
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* ability to preserve the pixel ordering depends on the filter. |
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* |
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* <p> |
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* This method is public as a side effect |
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* of this class implementing |
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* the <code>ImageProducer</code> interface. |
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* It should not be called from user code, |
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* and its behavior if called from user code is unspecified. |
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* |
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* @see ImageConsumer |
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*/ |
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public synchronized void requestTopDownLeftRightResend(ImageConsumer ic) { |
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if (proxies != null) { |
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ImageFilter imgf = (ImageFilter) proxies.get(ic); |
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if (imgf != null) { |
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imgf.resendTopDownLeftRight(src); |
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} |
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} |
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} |
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} |