001 /*
002 * Copyright 1995-2000 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.awt.image;
027
028 /**
029 * The interface for objects which can produce the image data for Images.
030 * Each image contains an ImageProducer which is used to reconstruct
031 * the image whenever it is needed, for example, when a new size of the
032 * Image is scaled, or when the width or height of the Image is being
033 * requested.
034 *
035 * @see ImageConsumer
036 *
037 * @version 1.27 05/05/07
038 * @author Jim Graham
039 */
040 public interface ImageProducer {
041 /**
042 * Registers an <code>ImageConsumer</code> with the
043 * <code>ImageProducer</code> for access to the image data
044 * during a later reconstruction of the <code>Image</code>.
045 * The <code>ImageProducer</code> may, at its discretion,
046 * start delivering the image data to the consumer
047 * using the <code>ImageConsumer</code> interface immediately,
048 * or when the next available image reconstruction is triggered
049 * by a call to the <code>startProduction</code> method.
050 * @param ic the specified <code>ImageConsumer</code>
051 * @see #startProduction
052 */
053 public void addConsumer(ImageConsumer ic);
054
055 /**
056 * Determines if a specified <code>ImageConsumer</code>
057 * object is currently registered with this
058 * <code>ImageProducer</code> as one of its consumers.
059 * @param ic the specified <code>ImageConsumer</code>
060 * @return <code>true</code> if the specified
061 * <code>ImageConsumer</code> is registered with
062 * this <code>ImageProducer</code>;
063 * <code>false</code> otherwise.
064 */
065 public boolean isConsumer(ImageConsumer ic);
066
067 /**
068 * Removes the specified <code>ImageConsumer</code> object
069 * from the list of consumers currently registered to
070 * receive image data. It is not considered an error
071 * to remove a consumer that is not currently registered.
072 * The <code>ImageProducer</code> should stop sending data
073 * to this consumer as soon as is feasible.
074 * @param ic the specified <code>ImageConsumer</code>
075 */
076 public void removeConsumer(ImageConsumer ic);
077
078 /**
079 * Registers the specified <code>ImageConsumer</code> object
080 * as a consumer and starts an immediate reconstruction of
081 * the image data which will then be delivered to this
082 * consumer and any other consumer which might have already
083 * been registered with the producer. This method differs
084 * from the addConsumer method in that a reproduction of
085 * the image data should be triggered as soon as possible.
086 * @param ic the specified <code>ImageConsumer</code>
087 * @see #addConsumer
088 */
089 public void startProduction(ImageConsumer ic);
090
091 /**
092 * Requests, on behalf of the <code>ImageConsumer</code>,
093 * that the <code>ImageProducer</code> attempt to resend
094 * the image data one more time in TOPDOWNLEFTRIGHT order
095 * so that higher quality conversion algorithms which
096 * depend on receiving pixels in order can be used to
097 * produce a better output version of the image. The
098 * <code>ImageProducer</code> is free to
099 * ignore this call if it cannot resend the data in that
100 * order. If the data can be resent, the
101 * <code>ImageProducer</code> should respond by executing
102 * the following minimum set of <code>ImageConsumer</code>
103 * method calls:
104 * <pre>
105 * ic.setHints(TOPDOWNLEFTRIGHT | < otherhints >);
106 * ic.setPixels(...); // As many times as needed
107 * ic.imageComplete();
108 * </pre>
109 * @param ic the specified <code>ImageConsumer</code>
110 * @see ImageConsumer#setHints
111 */
112 public void requestTopDownLeftRightResend(ImageConsumer ic);
113 }
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