Managing the Music and Sound Effects - Learning LibGDX Game Development - page 315

The AudioManager class is a singleton class so that we can access it from anywhere
in the code. It features a couple of overloaded play() methods just like the original
Sound and Music interfaces. The advantage of overloading these methods is that
you can make some parameters optional. The methods in this class check against
the values in GamePreferences , which holds the currently loaded audio settings
among others. If the checkbox for sounds is not selected in the Options menu,
GamePreferences.instance.sound will return false , and therefore any call of
AudioManager class's play() will be aborted before the actual play() call of a
sound is executed.
Next, add the following code to the same class:
public void play (Music music) {
stopMusic();
playingMusic = music;
if (GamePreferences.instance.music) {
music.setLooping(true);
music.setVolume(GamePreferences.instance.volMusic);
music.play();
}
}
public void stopMusic () {
if (playingMusic != null) playingMusic.stop();
}
public void onSettingsUpdated () {
if (playingMusic == null) return;
playingMusic.setVolume(GamePreferences.instance.volMusic);
if (GamePreferences.instance.music) {
if (!playingMusic.isPlaying()) playingMusic.play();
} else {
playingMusic.pause();
}
}
This code adds another overloaded play() method, which takes an instance of
Music that will be played. If music is already playing, it is stopped first. Then, new
music is initialized for playback and started if Music is enabled in the game settings.
The onSettingsUpdated() method is used to allow the Options menu to inform
AudioManager when settings have changed to execute appropriate actions, such as
setting a new music volume.