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Java > Open Source Codes > org > jivesoftware > smack > util > ObservableReader


1 /**
2  * $RCSfile$
3  * $Revision: 2408 $
4  * $Date: 2004-11-02 20:53:30 -0300 (Tue, 02 Nov 2004) $
5  *
6  * Copyright 2003-2004 Jive Software.
7  *
8  * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
9  * you may not use this file except in compliance with the License.
10  * You may obtain a copy of the License at
11  *
12  * http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20
21 package org.jivesoftware.smack.util;
22
23 import java.io.*;
24 import java.util.*;
25
26 /**
27  * An ObservableReader is a wrapper on a Reader that notifies to its listeners when
28  * reading character streams.
29  *
30  * @author Gaston Dombiak
31  */
32 public class ObservableReader extends Reader {
33
34     Reader wrappedReader = null;
35     List listeners = new ArrayList();
36
37     public ObservableReader(Reader wrappedReader) {
38         this.wrappedReader = wrappedReader;
39     }
40         
41     public int read(char[] cbuf, int off, int len) throws IOException {
42         int count = wrappedReader.read(cbuf, off, len);
43         if (count > 0) {
44             String JavaDoc str = new String JavaDoc(cbuf, off, count);
45             // Notify that a new string has been read
46 ReaderListener[] readerListeners = null;
47             synchronized (listeners) {
48                 readerListeners = new ReaderListener[listeners.size()];
49                 listeners.toArray(readerListeners);
50             }
51             for (int i = 0; i < readerListeners.length; i++) {
52                 readerListeners[i].read(str);
53             }
54         }
55         return count;
56     }
57
58     public void close() throws IOException {
59         wrappedReader.close();
60     }
61
62     public int read() throws IOException {
63         return wrappedReader.read();
64     }
65
66     public int read(char cbuf[]) throws IOException {
67         return wrappedReader.read(cbuf);
68     }
69
70     public long skip(long n) throws IOException {
71         return wrappedReader.skip(n);
72     }
73
74     public boolean ready() throws IOException {
75         return wrappedReader.ready();
76     }
77
78     public boolean markSupported() {
79         return wrappedReader.markSupported();
80     }
81
82     public void mark(int readAheadLimit) throws IOException {
83         wrappedReader.mark(readAheadLimit);
84     }
85
86     public void reset() throws IOException {
87         wrappedReader.reset();
88     }
89
90     /**
91      * Adds a reader listener to this reader that will be notified when
92      * new strings are read.
93      *
94      * @param readerListener a reader listener.
95      */
96     public void addReaderListener(ReaderListener readerListener) {
97         if (readerListener == null) {
98             return;
99         }
100         synchronized (listeners) {
101             if (!listeners.contains(readerListener)) {
102                 listeners.add(readerListener);
103             }
104         }
105     }
106
107     /**
108      * Removes a reader listener from this reader.
109      *
110      * @param readerListener a reader listener.
111      */
112     public void removeReaderListener(ReaderListener readerListener) {
113         synchronized (listeners) {
114             listeners.remove(readerListener);
115         }
116     }
117
118 }
119
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