X Tutup

/* * Copyright (c) 1995, 2011, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.awt.image; import java.util.Hashtable; /** * This class implements a filter for the set of interface methods that * are used to deliver data from an ImageProducer to an ImageConsumer. * It is meant to be used in conjunction with a FilteredImageSource * object to produce filtered versions of existing images. It is a * base class that provides the calls needed to implement a "Null filter" * which has no effect on the data being passed through. Filters should * subclass this class and override the methods which deal with the * data that needs to be filtered and modify it as necessary. * * @see FilteredImageSource * @see ImageConsumer * * @author Jim Graham */ public class ImageFilter implements ImageConsumer, Cloneable { /** * The consumer of the particular image data stream for which this * instance of the ImageFilter is filtering data. It is not * initialized during the constructor, but rather during the * getFilterInstance() method call when the FilteredImageSource * is creating a unique instance of this object for a particular * image data stream. * @see #getFilterInstance * @see ImageConsumer */ protected ImageConsumer consumer; /** * Returns a unique instance of an ImageFilter object which will * actually perform the filtering for the specified ImageConsumer. * The default implementation just clones this object. *

* Note: This method is intended to be called by the ImageProducer * of the Image whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @param ic the specified ImageConsumer * @return an ImageFilter used to perform the * filtering for the specified ImageConsumer. */ public ImageFilter getFilterInstance(ImageConsumer ic) { ImageFilter instance = (ImageFilter) clone(); instance.consumer = ic; return instance; } /** * Filters the information provided in the setDimensions method * of the ImageConsumer interface. *

* Note: This method is intended to be called by the ImageProducer * of the Image whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @see ImageConsumer#setDimensions */ public void setDimensions(int width, int height) { consumer.setDimensions(width, height); } /** * Passes the properties from the source object along after adding a * property indicating the stream of filters it has been run through. *

* Note: This method is intended to be called by the ImageProducer * of the Image whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * * @param props the properties from the source object * @exception NullPointerException if props is null */ public void setProperties(Hashtable props) { Hashtable p = (Hashtable)props.clone(); Object o = p.get("filters"); if (o == null) { p.put("filters", toString()); } else if (o instanceof String) { p.put("filters", ((String) o)+toString()); } consumer.setProperties(p); } /** * Filter the information provided in the setColorModel method * of the ImageConsumer interface. *

* Note: This method is intended to be called by the ImageProducer * of the Image whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @see ImageConsumer#setPixels */ public void setPixels(int x, int y, int w, int h, ColorModel model, byte pixels[], int off, int scansize) { consumer.setPixels(x, y, w, h, model, pixels, off, scansize); } /** * Filters the information provided in the setPixels method of the * ImageConsumer interface which takes an array of integers. *

* Note: This method is intended to be called by the ImageProducer * of the Image whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @see ImageConsumer#setPixels */ public void setPixels(int x, int y, int w, int h, ColorModel model, int pixels[], int off, int scansize) { consumer.setPixels(x, y, w, h, model, pixels, off, scansize); } /** * Filters the information provided in the imageComplete method of * the ImageConsumer interface. *

* Note: This method is intended to be called by the ImageProducer * of the Image whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @see ImageConsumer#imageComplete */ public void imageComplete(int status) { consumer.imageComplete(status); } /** * Responds to a request for a TopDownLeftRight (TDLR) ordered resend * of the pixel data from an ImageConsumer. * When an ImageConsumer being fed * by an instance of this ImageFilter * requests a resend of the data in TDLR order, * the FilteredImageSource * invokes this method of the ImageFilter. * *

* * An ImageFilter subclass might override this method or not, * depending on if and how it can send data in TDLR order. * Three possibilities exist: * *

* Do not override this method. * This makes the subclass use the default implementation, * which is to * forward the request * to the indicated ImageProducer * using this filter as the requesting ImageConsumer. * This behavior * is appropriate if the filter can determine * that it will forward the pixels * in TDLR order if its upstream producer object * sends them in TDLR order. * *
* Override the method to simply send the data. * This is appropriate if the filter can handle the request itself — * for example, * if the generated pixels have been saved in some sort of buffer. * *
* Override the method to do nothing. * This is appropriate * if the filter cannot produce filtered data in TDLR order. *

* * @see ImageProducer#requestTopDownLeftRightResend * @param ip the ImageProducer that is feeding this instance of * the filter - also the ImageProducer that the request should be * forwarded to if necessary * @exception NullPointerException if ip is null */ public void resendTopDownLeftRight(ImageProducer ip) { ip.requestTopDownLeftRightResend(this); } /** * Clones this object. */ public Object clone() { try { return super.clone(); } catch (CloneNotSupportedException e) { // this shouldn't happen, since we are Cloneable throw new InternalError(e); } } }

X Tutup