org.jivesoftware.smack.util.ObservableWriter Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of smackx Show documentation

Smack is an Open Source XMPP (Jabber) client library for instant messaging and presence. This library provides the client side functionality as specified in the extensions to the XMPP specifications as related to the client side of said specifications.

The newest version!

/**
 * $RCSfile$
 * $Revision: 7071 $
 * $Date: 2007-02-11 18:59:05 -0600 (Sun, 11 Feb 2007) $
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smack.util;

import java.io.*;
import java.util.*;

/**
 * An ObservableWriter is a wrapper on a Writer that notifies to its listeners when
 * writing to character streams.
 * 
 * @author Gaston Dombiak
 */
public class ObservableWriter extends Writer {

    Writer wrappedWriter = null;
    List listeners = new ArrayList();

    public ObservableWriter(Writer wrappedWriter) {
        this.wrappedWriter = wrappedWriter;
    }

    public void write(char cbuf[], int off, int len) throws IOException {
        wrappedWriter.write(cbuf, off, len);
        String str = new String(cbuf, off, len);
        notifyListeners(str);
    }

    public void flush() throws IOException {
        wrappedWriter.flush();
    }

    public void close() throws IOException {
        wrappedWriter.close();
    }

    public void write(int c) throws IOException {
        wrappedWriter.write(c);
    }

    public void write(char cbuf[]) throws IOException {
        wrappedWriter.write(cbuf);
        String str = new String(cbuf);
        notifyListeners(str);
    }

    public void write(String str) throws IOException {
        wrappedWriter.write(str);
        notifyListeners(str);
    }

    public void write(String str, int off, int len) throws IOException {
        wrappedWriter.write(str, off, len);
        str = str.substring(off, off + len);
        notifyListeners(str);
    }

    /**
     * Notify that a new string has been written.
     * 
     * @param str the written String to notify 
     */
    private void notifyListeners(String str) {
        WriterListener[] writerListeners = null;
        synchronized (listeners) {
            writerListeners = new WriterListener[listeners.size()];
            listeners.toArray(writerListeners);
        }
        for (int i = 0; i < writerListeners.length; i++) {
            writerListeners[i].write(str);
        }
    }

    /**
     * Adds a writer listener to this writer that will be notified when
     * new strings are sent.
     *
     * @param writerListener a writer listener.
     */
    public void addWriterListener(WriterListener writerListener) {
        if (writerListener == null) {
            return;
        }
        synchronized (listeners) {
            if (!listeners.contains(writerListener)) {
                listeners.add(writerListener);
            }
        }
    }

    /**
     * Removes a writer listener from this writer.
     *
     * @param writerListener a writer listener.
     */
    public void removeWriterListener(WriterListener writerListener) {
        synchronized (listeners) {
            listeners.remove(writerListener);
        }
    }

}