MidiPlayer.java

package com.xenoage.zong.android;

import android.content.Context;
import android.media.MediaPlayer;
import android.net.Uri;

import com.leff.midi.MidiFile;
import com.xenoage.zong.android.io.midi.out.AndroidMidiSequenceWriter;
import com.xenoage.zong.core.Score;
import com.xenoage.zong.io.midi.out.MidiConverter;
import com.xenoage.zong.io.midi.out.MidiSequence;

import java.io.File;
import java.io.IOException;

import static com.xenoage.zong.io.midi.out.MidiConverter.Options.optionsForPlayback;

/**
 * Midi playback of scores.
 * 
 * @author Andreas Wenger
 */
public class MidiPlayer {

	private MediaPlayer mediaPlayer = null;


	/**
	 * Opens the given {@link Score}.
	 * An Android context must be given, that is needed to determine the directory
	 * for the temporary MIDI file and to create the media player.
	 */
	public void open(Score score, Context context) {
		try {
			File outputFile = File.createTempFile("zong", ".mid", context.getCacheDir());
			MidiSequence<MidiFile> sequence = MidiConverter.convertToSequence(score,
				optionsForPlayback, new AndroidMidiSequenceWriter());
			sequence.getSequence().writeToFile(outputFile);

			stop();
			
			mediaPlayer = MediaPlayer.create(context, Uri.fromFile(outputFile));

		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * Starts playback, if a file is loaded.
	 */
	public void start() {
		if (mediaPlayer != null) {
			//TODO: needs prepare() after stopping!
			/* try {
				mediaPlayer.prepare();
			} catch (IOException e) {
			} */
			mediaPlayer.start();
		}
	}

	/**
	 * Pauses playback, if a file is loaded.
	 */
	public void pause() {
		if (mediaPlayer != null)
			mediaPlayer.pause();
	}

	/**
	 * Stops playback, if a file is loaded.
	 */
	public void stop() {
		if (mediaPlayer != null)
			mediaPlayer.stop();
	}

}