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.Reader; 021import java.util.ArrayList; 022import java.util.List; 023 024 025/** 026 * An ObservableReader is a wrapper on a Reader that notifies to its listeners when 027 * reading character streams. 028 * 029 * @author Gaston Dombiak 030 */ 031public class ObservableReader extends Reader { 032 033 Reader wrappedReader = null; 034 List<ReaderListener> listeners = new ArrayList<ReaderListener>(); 035 036 public ObservableReader(Reader wrappedReader) { 037 this.wrappedReader = wrappedReader; 038 } 039 040 public int read(char[] cbuf, int off, int len) throws IOException { 041 int count = wrappedReader.read(cbuf, off, len); 042 if (count > 0) { 043 String str = new String(cbuf, off, count); 044 // Notify that a new string has been read 045 ReaderListener[] readerListeners = null; 046 synchronized (listeners) { 047 readerListeners = new ReaderListener[listeners.size()]; 048 listeners.toArray(readerListeners); 049 } 050 for (int i = 0; i < readerListeners.length; i++) { 051 readerListeners[i].read(str); 052 } 053 } 054 return count; 055 } 056 057 public void close() throws IOException { 058 wrappedReader.close(); 059 } 060 061 public int read() throws IOException { 062 return wrappedReader.read(); 063 } 064 065 public int read(char[] cbuf) throws IOException { 066 return wrappedReader.read(cbuf); 067 } 068 069 public long skip(long n) throws IOException { 070 return wrappedReader.skip(n); 071 } 072 073 public boolean ready() throws IOException { 074 return wrappedReader.ready(); 075 } 076 077 public boolean markSupported() { 078 return wrappedReader.markSupported(); 079 } 080 081 public void mark(int readAheadLimit) throws IOException { 082 wrappedReader.mark(readAheadLimit); 083 } 084 085 public void reset() throws IOException { 086 wrappedReader.reset(); 087 } 088 089 /** 090 * Adds a reader listener to this reader that will be notified when 091 * new strings are read. 092 * 093 * @param readerListener a reader listener. 094 */ 095 public void addReaderListener(ReaderListener readerListener) { 096 if (readerListener == null) { 097 return; 098 } 099 synchronized (listeners) { 100 if (!listeners.contains(readerListener)) { 101 listeners.add(readerListener); 102 } 103 } 104 } 105 106 /** 107 * Removes a reader listener from this reader. 108 * 109 * @param readerListener a reader listener. 110 */ 111 public void removeReaderListener(ReaderListener readerListener) { 112 synchronized (listeners) { 113 listeners.remove(readerListener); 114 } 115 } 116 117}