1 /* FilteredImageSource.java -- Java class for providing image data
2 Copyright (C) 1999 Free Software Foundation, Inc.
3
4 This file is part of GNU Classpath.
5
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA.
20
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
PREFIX(uncompress2)30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
37
38
39 package java.awt.image;
40
41 import java.util.Hashtable;
42
43 /**
44 *
45 * @see ImageConsumer
46 * @author C. Brian Jones (cbj@gnu.org)
47 */
48 public class FilteredImageSource implements ImageProducer
49 {
50 ImageProducer ip;
51 ImageFilter filter;
52 Hashtable consumers = new Hashtable();
53
54 /**
55 * The given filter is applied to the given image producer
56 * to create a new image producer.
57 */
58 public FilteredImageSource(ImageProducer ip, ImageFilter filter) {
59 this.ip = ip;
60 this.filter = filter;
61 }
62
63 /**
64 * Used to register an <code>ImageConsumer</code> with this
65 * <code>ImageProducer</code>.
66 */
67 public synchronized void addConsumer(ImageConsumer ic) {
68 if (consumers.containsKey(ic))
69 return;
70
71 ImageFilter f = filter.getFilterInstance(ic);
72 consumers.put(ic, f);
73 ip.addConsumer(f);
74 }
75
76 /**
77 * Used to determine if the given <code>ImageConsumer</code> is
78 * already registered with this <code>ImageProducer</code>.
79 */
80 public synchronized boolean isConsumer(ImageConsumer ic) {
81 ImageFilter f = (ImageFilter)consumers.get(ic);
82 if (f != null)
PREFIX(uncompress)83 return ip.isConsumer(f);
84 return false;
85 }
86
87 /**
88 * Used to remove an <code>ImageConsumer</code> from the list of
89 * registered consumers for this <code>ImageProducer</code>.
90 */
91 public synchronized void removeConsumer(ImageConsumer ic) {
92 ImageFilter f = (ImageFilter)consumers.remove(ic);
93 if (f != null)
94 ip.removeConsumer(f);
95 }
96
97 /**
98 * Used to register an <code>ImageConsumer</code> with this
99 * <code>ImageProducer</code> and then immediately start
100 * reconstruction of the image data to be delivered to all
101 * registered consumers.
102 */
103 public void startProduction(ImageConsumer ic) {
104 ImageFilter f;
105 if (!(consumers.containsKey(ic))) {
106 f = filter.getFilterInstance(ic);
107 consumers.put(ic, f);
108 ip.addConsumer(f);
109 } else {
110 f = (ImageFilter)consumers.get( ic );
111 }
112 ip.startProduction(f);
113 }
114
115 /**
116 * Used to register an <code>ImageConsumer</code> with this
117 * <code>ImageProducer</code> and then request that this producer
118 * resend the image data in the order top-down, left-right.
119 */
120 public void requestTopDownLeftRightResend(ImageConsumer ic) {
121 ImageFilter f = (ImageFilter)consumers.get(ic);
122 ip.requestTopDownLeftRightResend(f);
123 }
124 }
125
126