Game Development 101 - Beginning Android Games - page 83

This directly translates into the Audio , Music , and Sound interfaces (shown in Listings 3-3
through 3-5, respectively).
Listing 3-3. The Audio Interface
package com.badlogic.androidgames.framework;
public interface Audio {
public Music newMusic(String filename);
public Sound newSound(String filename);
}
The Audio interface is our way to create new Music and Sound instances. A Music instance
represents a streamed audio file. A Sound instance represents a short sound effect that we keep
entirely in memory. The methods Audio.newMusic() and Audio.newSound() both take a filename
as an argument and throw an IOException in case the loading process fails (for example,
when the specified file does not exist or is corrupt). The filenames refer to asset files in our
application's APK file.
Listing 3-4. The Music Interface
package com.badlogic.androidgames.framework;
public interface Music {
public void play();
public void stop();
public void pause();
public void setLooping( boolean looping);
public void setVolume( float volume);
public boolean isPlaying();
public boolean isStopped();
public boolean isLooping();
public void dispose();
}
The Music interface is a little bit more involved. It features methods to start playing the
music stream, pausing and stopping it, and setting it to loop playback, which means it will
automatically start from the beginning when it reaches the end of the audio file. Additionally,
we can set the volume as a float in the range of 0 (silent) to 1 (maximum volume). A couple of
getter methods are also available that allow us to poll the current state of the Music instance.
Once we no longer need the Music instance, we have to dispose of it. This will close any system
resources, such as the file from which the audio was streamed.