1 /** 2 * $RCSfile$ 3 * $Revision$ 4 * $Date$ 5 * 6 * Copyright 2003-2007 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 ObservableWriter is a wrapper on a Writer that notifies to its listeners when 28 * writing to character streams. 29 * 30 * @author Gaston Dombiak 31 */ 32 public class ObservableWriter extends Writer { 33 34 Writer wrappedWriter = null; 35 List<WriterListener> listeners = new ArrayList<WriterListener>(); 36 ObservableWriter(Writer wrappedWriter)37 public ObservableWriter(Writer wrappedWriter) { 38 this.wrappedWriter = wrappedWriter; 39 } 40 write(char cbuf[], int off, int len)41 public void write(char cbuf[], int off, int len) throws IOException { 42 wrappedWriter.write(cbuf, off, len); 43 String str = new String(cbuf, off, len); 44 notifyListeners(str); 45 } 46 flush()47 public void flush() throws IOException { 48 wrappedWriter.flush(); 49 } 50 close()51 public void close() throws IOException { 52 wrappedWriter.close(); 53 } 54 write(int c)55 public void write(int c) throws IOException { 56 wrappedWriter.write(c); 57 } 58 write(char cbuf[])59 public void write(char cbuf[]) throws IOException { 60 wrappedWriter.write(cbuf); 61 String str = new String(cbuf); 62 notifyListeners(str); 63 } 64 write(String str)65 public void write(String str) throws IOException { 66 wrappedWriter.write(str); 67 notifyListeners(str); 68 } 69 write(String str, int off, int len)70 public void write(String str, int off, int len) throws IOException { 71 wrappedWriter.write(str, off, len); 72 str = str.substring(off, off + len); 73 notifyListeners(str); 74 } 75 76 /** 77 * Notify that a new string has been written. 78 * 79 * @param str the written String to notify 80 */ notifyListeners(String str)81 private void notifyListeners(String str) { 82 WriterListener[] writerListeners = null; 83 synchronized (listeners) { 84 writerListeners = new WriterListener[listeners.size()]; 85 listeners.toArray(writerListeners); 86 } 87 for (int i = 0; i < writerListeners.length; i++) { 88 writerListeners[i].write(str); 89 } 90 } 91 92 /** 93 * Adds a writer listener to this writer that will be notified when 94 * new strings are sent. 95 * 96 * @param writerListener a writer listener. 97 */ addWriterListener(WriterListener writerListener)98 public void addWriterListener(WriterListener writerListener) { 99 if (writerListener == null) { 100 return; 101 } 102 synchronized (listeners) { 103 if (!listeners.contains(writerListener)) { 104 listeners.add(writerListener); 105 } 106 } 107 } 108 109 /** 110 * Removes a writer listener from this writer. 111 * 112 * @param writerListener a writer listener. 113 */ removeWriterListener(WriterListener writerListener)114 public void removeWriterListener(WriterListener writerListener) { 115 synchronized (listeners) { 116 listeners.remove(writerListener); 117 } 118 } 119 120 } 121