MusicEngine.java

package com.bladecoder.engine.model;

import com.badlogic.gdx.audio.Music;
import com.badlogic.gdx.utils.Json;
import com.badlogic.gdx.utils.Json.Serializable;
import com.badlogic.gdx.utils.JsonValue;
import com.bladecoder.engine.assets.AssetConsumer;
import com.bladecoder.engine.assets.EngineAssetManager;
import com.bladecoder.engine.util.EngineLogger;

/**
 * Simple music engine.
 * 
 * Plays a music file, if another music is playing, stops it before playing the
 * new music.
 * 
 * @author rgarcia
 */
public class MusicEngine implements Serializable, AssetConsumer {
	private MusicDesc desc = null;

	private Music music = null;

	private float currentMusicDelay = 0;
	private boolean isPlayingSer = false;
	private float musicPosSer = 0;
	transient private boolean isPaused = false;

	public void playMusic() {
		if (music != null && !music.isPlaying()) {
			music.play();
			music.setLooping(desc.isLoop());
		}
	}

	public void pauseMusic() {
		if (music != null && music.isPlaying()) {
			music.pause();
			isPaused = true;
		}
	}

	public void resumeMusic() {
		if (music != null && isPaused) {
			music.play();
			isPaused = false;
		}
	}

	public void stopMusic() {
		if (music != null)
			music.stop();
	}

	public void setMusic(MusicDesc d) {
		stopMusic();
		currentMusicDelay = 0;

		if (d != null) {
			if (desc != null)
				dispose();

			desc = new MusicDesc(d);

			retrieveAssets();
		} else {
			dispose();
			desc = null;
		}
	}
	

	public void setVolume(float volume) {
		if(desc != null)
			desc.setVolume(volume);
		
		if(music != null)
			music.setVolume(volume);
	}


	public void leaveScene(MusicDesc newMusicDesc) {

		if (desc != null && !desc.isStopWhenLeaving() && 
				(newMusicDesc == null || newMusicDesc.getFilename().equals(desc.getFilename())))
			return;

		if (desc != null) {
			currentMusicDelay = 0;
			stopMusic();
			dispose();
		}

		if (newMusicDesc != null) {
			desc = new MusicDesc(newMusicDesc);
		} else {
			desc = null;
		}
	}

	public void update(float delta) {
		// music delay update
		if (music != null && !music.isPlaying()) {
			boolean initialTime = false;

			if (currentMusicDelay <= desc.getInitialDelay())
				initialTime = true;

			currentMusicDelay += delta;

			if (initialTime) {
				if (currentMusicDelay > desc.getInitialDelay())
					playMusic();
			} else {
				if (desc.getRepeatDelay() >= 0 && currentMusicDelay > desc.getRepeatDelay() + desc.getInitialDelay()) {
					currentMusicDelay = desc.getInitialDelay();
					playMusic();
				}
			}
		}
	}

	@Override
	public void dispose() {
		if (music != null) {
			EngineLogger.debug("DISPOSING MUSIC: " + desc.getFilename());
			EngineAssetManager.getInstance().disposeMusic(desc.getFilename());
			music = null;
			desc = null;
		}
	}

	@Override
	public void loadAssets() {
		if (music == null && desc != null) {
			EngineLogger.debug("LOADING MUSIC: " + desc.getFilename());
			EngineAssetManager.getInstance().loadMusic(desc.getFilename());
		}
	}

	@Override
	public void retrieveAssets() {
		if (music == null && desc != null) {
			
			if(!EngineAssetManager.getInstance().isLoaded(EngineAssetManager.MUSIC_DIR + desc.getFilename())) {
				loadAssets();
				EngineAssetManager.getInstance().finishLoading();
			}
			
			EngineLogger.debug("RETRIEVING MUSIC: " + desc.getFilename());
			
			music = EngineAssetManager.getInstance().getMusic(desc.getFilename());
			
			if(music != null)
				music.setVolume(desc.getVolume());

			if (isPlayingSer) {
				playMusic();
				
				if (music != null) {
					music.setPosition(musicPosSer);
					musicPosSer = 0f;
				}

				isPlayingSer = false;
			}
		}
	}

	@Override
	public void write(Json json) {
		json.writeValue("desc", desc);
		json.writeValue("currentMusicDelay", currentMusicDelay);
		json.writeValue("isPlaying", music != null && (music.isPlaying()|| isPaused));
		json.writeValue("musicPos", music != null && (music.isPlaying()|| isPaused) ? music.getPosition() : 0f);
	}

	@Override
	public void read(Json json, JsonValue jsonData) {
		desc = json.readValue("desc", MusicDesc.class, jsonData);
		currentMusicDelay = json.readValue("currentMusicDelay", float.class, jsonData);
		isPlayingSer = json.readValue("isPlaying", boolean.class, jsonData);
		musicPosSer = json.readValue("musicPos", float.class, jsonData);
	}
}