URLStream.java

//
// Nenya library - tools for developing networked games
// Copyright (C) 2002-2012 Three Rings Design, Inc., All Rights Reserved
// https://github.com/threerings/nenya
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

package com.threerings.openal;

import java.util.ArrayList;

import java.io.IOException;

import java.net.URL;

import java.nio.ByteBuffer;

import com.google.common.collect.Lists;

/**
 * An audio stream read from one or more URLs.
 */
public class URLStream extends Stream
{
    /**
     * Creates a new stream for the specified URL.
     *
     * @param loop whether or not to play the file in a continuous loop
     * if there's nothing on the queue
     */
    public URLStream (SoundManager soundmgr, URL url, boolean loop)
        throws IOException
    {
        super(soundmgr);
        _url = new QueuedURL(url, loop);
        _decoder = StreamDecoder.createInstance(url);
    }

    /**
     * Adds an element to the queue of URLs to play.
     *
     * @param loop if true, play this file in a loop if there's nothing else
     * on the queue
     */
    public void queueURL (URL url, boolean loop)
    {
        _queue.add(new QueuedURL(url, loop));
    }

    @Override
    protected int getFormat ()
    {
        return _decoder.getFormat();
    }

    @Override
    protected int getFrequency ()
    {
        return _decoder.getFrequency();
    }

    @Override
    protected int populateBuffer (ByteBuffer buf)
        throws IOException
    {
        int read = _decoder.read(buf);
        while (buf.hasRemaining() && (!_queue.isEmpty() || _url.loop)) {
            if (!_queue.isEmpty()) {
                _url = _queue.remove(0);
            }
            _decoder = StreamDecoder.createInstance(_url.url);
            read = Math.max(0, read);
            read += _decoder.read(buf);
        }
        return read;
    }

    /** The URL currently being played. */
    protected QueuedURL _url;

    /** The stream decoder for the current URL. */
    protected StreamDecoder _decoder;

    /** The queue of URLs to play after the current one. */
    protected ArrayList<QueuedURL> _queue = Lists.newArrayList();

    /** A URL queued for play. */
    protected class QueuedURL
    {
        /** The URL of the file to play. */
        public URL url;

        /** Whether or not to play the URL in a loop when there's nothing
         * in the queue. */
        public boolean loop;

        public QueuedURL (URL url, boolean loop)
        {
            this.url = url;
            this.loop = loop;
        }
    }
}