001/** 002 * 003 * Copyright 2003-2007 Jive Software. 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.jivesoftware.smack.util; 018 019import java.io.IOException; 020import java.io.Writer; 021import java.util.ArrayList; 022import java.util.List; 023 024/** 025 * An ObservableWriter is a wrapper on a Writer that notifies to its listeners when 026 * writing to character streams. 027 * 028 * @author Gaston Dombiak 029 */ 030public class ObservableWriter extends Writer { 031 032 Writer wrappedWriter = null; 033 List<WriterListener> listeners = new ArrayList<WriterListener>(); 034 035 public ObservableWriter(Writer wrappedWriter) { 036 this.wrappedWriter = wrappedWriter; 037 } 038 039 public void write(char[] cbuf, int off, int len) throws IOException { 040 wrappedWriter.write(cbuf, off, len); 041 String str = new String(cbuf, off, len); 042 notifyListeners(str); 043 } 044 045 public void flush() throws IOException { 046 wrappedWriter.flush(); 047 } 048 049 public void close() throws IOException { 050 wrappedWriter.close(); 051 } 052 053 public void write(int c) throws IOException { 054 wrappedWriter.write(c); 055 } 056 057 public void write(char[] cbuf) throws IOException { 058 wrappedWriter.write(cbuf); 059 String str = new String(cbuf); 060 notifyListeners(str); 061 } 062 063 public void write(String str) throws IOException { 064 wrappedWriter.write(str); 065 notifyListeners(str); 066 } 067 068 public void write(String str, int off, int len) throws IOException { 069 wrappedWriter.write(str, off, len); 070 str = str.substring(off, off + len); 071 notifyListeners(str); 072 } 073 074 /** 075 * Notify that a new string has been written. 076 * 077 * @param str the written String to notify 078 */ 079 private void notifyListeners(String str) { 080 WriterListener[] writerListeners = null; 081 synchronized (listeners) { 082 writerListeners = new WriterListener[listeners.size()]; 083 listeners.toArray(writerListeners); 084 } 085 for (int i = 0; i < writerListeners.length; i++) { 086 writerListeners[i].write(str); 087 } 088 } 089 090 /** 091 * Adds a writer listener to this writer that will be notified when 092 * new strings are sent. 093 * 094 * @param writerListener a writer listener. 095 */ 096 public void addWriterListener(WriterListener writerListener) { 097 if (writerListener == null) { 098 return; 099 } 100 synchronized (listeners) { 101 if (!listeners.contains(writerListener)) { 102 listeners.add(writerListener); 103 } 104 } 105 } 106 107 /** 108 * Removes a writer listener from this writer. 109 * 110 * @param writerListener a writer listener. 111 */ 112 public void removeWriterListener(WriterListener writerListener) { 113 synchronized (listeners) { 114 listeners.remove(writerListener); 115 } 116 } 117 118}