Media with JavaFX - Java 8 Recipes - page 684

new MediaPlayer instance. The following code checks for a prior media player to
be stopped:
if (mediaPlayer != null) {
mediaPlayer.stop();
}
So, here is where you create a MediaPlayer instance. A MediaPlayer object
is responsible for controlling the playing of media objects. Notice that a MediaPlay-
er will treat sound or video media the same in terms of playing, pausing, and stopping
media. When creating a media player, you specify the media and audioSpec-
trumListener attribute methods. Setting the autoPlay attribute to true will
play the audio media immediately after it has been loaded. The last thing to specify on
the MediaPlayer instance is an AudioSpectrumListener . So, what exactly is
this type of listener, you say? Well, according to the Javadoc, it is an observer receiving
periodic updates of the audio spectrum. In layman's terms, it is the audio media's
sound data such as volume, tempo, and so on. To create an instance of an Audi-
oSpectrumListener , you create an inner class that overrides the method spec-
trumDataUpdate() . You could have also used a lambda expression here; the ex-
ample uses the inner class to provide better insight into the functionality. Table 16-2
lists all the inbound parameters for the audio spectrum listener's method. For more de-
tails, refer to the Javadoc at http://docs.oracle.com/javase/8/javafx/
api/javafx/scene/media/AudioSpectrumListener.html .
Table 16-2 . The AudioSpectrumListener's Method spectrumDataUp-
date() Inbound Parameters
In the example, randomly colored circle nodes are created, positioned, and placed
on the scene based on the variable phases (array of floats). To draw each colored circle,
the circle's center X is incremented by five pixels and the circle's center Y is added