How do I handle media metadata in separate class? - javafx

Question

Im making a mediaplayer using JavaFX Media classes. I made a SongModel class, that incapsulates all metadata from a file and creates Media and MediaPlayer instances.
It looks something like this:
private final StringProperty album =
new SimpleStringProperty(this, "album");
public String getAlbum(){ return album.get(); }
public void setAlbum(String value){ album.set(value); }
public StringProperty albumProperty() { return album; }
There are also artist, year, title, and albumCover fields that look just like that. Also, MediaPlayer property is exposed as a read-only:
public MediaPlayer getMediaPlayer(){ return mediaPlayer.get(); }
public ReadOnlyObjectProperty<MediaPlayer> mediaPlayerProperty(){
return mediaPlayer.getReadOnlyProperty();
}
I use a MapChangelistener to check if the field is available and then pass it to the handleMetadata method:
private void initializeMedia(String url){
try {
final Media media = new Media(url);
media.getMetadata().addListener(new MapChangeListener<String, Object>(){
#Override
public void onChanged(MapChangeListener.Change<? extends String, ? extends Object> ch) {
if(ch.wasAdded()){
handleMetadata(ch.getKey(), ch.getValueAdded());
}
}
});
mediaPlayer.setValue(new MediaPlayer(media));
mediaPlayer.get().setOnError(new Runnable() {
#Override
public void run() {
String errorMessage = mediaPlayer.get().getError().getMessage();
System.out.println("MediaPlayer error: "+errorMessage);
}
});
}catch(RuntimeException e){
System.out.println("Construction error: "+e);
}
}
private void handleMetadata(String key, Object value){
if(key.equals("album")){
setAlbum(value.toString());
} else if (key.equals("artist")){
setArtist(value.toString());
} if (key.equals("title")){
setTitle(value.toString());
} if (key.equals("year")){
setYear(value.toString());
} if (key.equals("image")){
setAlbumCover((Image)value);
}
}
Then I made an AbstractView class that provides access to SongModel:
public abstract class AbstractView {
protected final SongModel songModel;
protected final Node viewNode;
public AbstractView(SongModel songModel){
this.songModel = songModel;
this.viewNode = initView();
}
public Node getViewNode() {
return viewNode;
}
protected abstract Node initView();
}
But when I try to make a MetadataView class, I run into some problems.
Heres how it looks:
public class MetadataView extends AbstractView{
public Label artist;
public Label album;
public Label title;
public Label year;
public ImageView albumCover;
public MetadataView(SongModel songModel) {
super(songModel);
}
#Override
protected Node initView() {
artist = new Label();
artist.setId("artist");
album = new Label();
album.setId("album");
title = new Label();
title.setId("title");
year = new Label();
year.setId("year");
final Reflection reflection = new Reflection();
reflection.setFraction(0.2);
final URL url = getClass().getResource("resources/defaultAlbum.png");
Image image = new Image(url.toString());
albumCover = new ImageView(image);
albumCover.setFitWidth(240);
albumCover.setPreserveRatio(true);
albumCover.setSmooth(true);
albumCover.setEffect(reflection);
final GridPane gp = new GridPane();
gp.setPadding(new Insets(10));
gp.setHgap(20);
gp.add(albumCover, 0,0,1, GridPane.REMAINING);
gp.add(title, 1,0);
gp.add(artist, 1,1);
gp.add(album, 1,2);
gp.add(year, 1,3);
final ColumnConstraints c0 = new ColumnConstraints();
final ColumnConstraints c1 = new ColumnConstraints();
c1.setHgrow(Priority.ALWAYS);
gp.getColumnConstraints().addAll(c0,c1);
final RowConstraints r0 = new RowConstraints();
r0.setValignment(VPos.TOP);
gp.getRowConstraints().addAll(r0,r0,r0,r0);
return gp;
}
}
And heres how I call it in the start method:
metaDataView = new MetadataView(songModel);
The problem is that it displays only default metadata without taking it from the songmodel class. I tried running metadata view code together with data handling in one class and everything worked, but when i try to put them in separate classes - it doesnt. Music runs just fine, its just the data thats not displaying. Could anybody tell me what am I missing? How do i make it display metadata from a SongModel class? Ive spent a lot of time on that and dont want it to go to waste.

Answer 1

After a day of searching I have found an answer: binds. All I had to do was to bind label property of SongModel class to label property of MetadataView class:
title.textProperty().bind(songModel.titleProperty());
artist.textProperty().bind(songModel.artistProperty());
album.textProperty().bind(songModel.albumProperty());
year.textProperty().bind(songModel.yearProperty());
albumCover.imageProperty().bind(songModel.albumCoverProperty());