выравнивание видео по центру в javafx

StackPane работал на меня. Комментарии в коде.

import java.io.File;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.Slider;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.media.AudioSpectrumListener;
import javafx.scene.media.MediaPlayer;
import javafx.scene.media.MediaView;
import javafx.scene.media.Media;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Duration;

public class MoviePlayer extends Application {

    public static void main(String[] args) {

        launch(args);
    }

    MediaPlayer mediaPlayer;
    private Label time;
    Duration duration;
    Button fullScreenButton;
    Scene scene;
    Media media;
    double width;
    double height;
    MediaView mediaView;




    //setScene Function
        public Scene setScene(double width, double height, Stage primaryStage) {
                StackPane root = new StackPane();//Change root to StackPane
                this.height = height;
                this.width = width;

                //Add your own path of the vidio that you want to play
                String path = "C:\\yourPath\\video.mp4";
                media = new Media(new File(path).toURI().toString());
                mediaPlayer = new MediaPlayer(media);

                //AutoPlay set to false
                //mediaPlayer.setAutoPlay(false);
                mediaView = new MediaView(mediaPlayer);

                final Timeline Slideout = new Timeline();
                final Timeline Slidein = new Timeline();

                // DropShadow effect
                //DropShadow dropshadow = new DropShadow();
                //dropshadow.setOffsetY(5.0);
                //dropshadow.setOffsetX(5.0);
                //dropshadow.setColor(Color.WHITE);
                //mediaView.setEffect(dropshadow);



                root.setOnMouseExited(new EventHandler<MouseEvent>() {
                    @Override
                    public void handle(MouseEvent event) {
                        Slideout.play();

                    }
                });


                root.setOnMouseEntered(new EventHandler<MouseEvent>() {
                    @Override
                    public void handle(MouseEvent event) {

                        Slidein.play();
                    }
                });


                final VBox vbox = new VBox();
                Slider slider = new Slider();
                vbox.getChildren().add(slider);



                //Play/pause Button
                  Image playButtonImage = new Image("file:///C:/Users/MANJEET SINGH/IdeaProjects/MoviePlayer/buttonImages/play.png");
                  ImageView iv1 = new ImageView(playButtonImage);
                  iv1.setFitHeight(25);
                  iv1.setFitWidth(25);
                    Image pauseButtonImage = new Image("file:///C:/Users/MANJEET SINGH/IdeaProjects/MoviePlayer/buttonImages/pause.png");
                    ImageView iv2 = new ImageView(pauseButtonImage);
                    iv2.setFitHeight(25);
                    iv2.setFitWidth(25);
                    final Button playButton = new Button();
                   playButton.setGraphic(iv1);
                    playButton.setStyle("-fx-background-color: Black");
                    //playButton.setAlignment(Pos.BOTTOM_CENTER);
                    playButton.setOnAction(new EventHandler<ActionEvent>() {
                        @Override
                        public void handle(ActionEvent event) {

                            MediaPlayer.Status status = mediaPlayer.getStatus();

                            if (status == MediaPlayer.Status.PAUSED
                                    || status == MediaPlayer.Status.READY
                                    || status == MediaPlayer.Status.STOPPED) {

                                mediaPlayer.play();
                                playButton.setGraphic(iv1);

                            } else {
                                mediaPlayer.pause();
                                playButton.setGraphic(iv2);
                            }
                        }
                    });

                    playButton.addEventHandler(MouseEvent.MOUSE_ENTERED, (MouseEvent e) -> {
                        playButton.setStyle("-fx-background-color: Black");
                        playButton.setStyle("-fx-body-color: Black");
                    });
                    playButton.addEventHandler(MouseEvent.MOUSE_EXITED, (MouseEvent e) -> {
                        playButton.setStyle("-fx-background-color: Black");
                    });


                    //Forward Button
            Image forwardButtonImage = new Image("file:///C:/Users/MANJEET SINGH/IdeaProjects/MoviePlayer/buttonImages/forwardbutton.png");
            ImageView ivforward = new ImageView(forwardButtonImage);
            ivforward.setFitHeight(25);
            ivforward.setFitWidth(25);

            final Button forwardButton = new Button();
            forwardButton.setGraphic(ivforward);
            forwardButton.setStyle("-fx-background-color: Black");

            forwardButton.setOnAction((ActionEvent e) -> {
                mediaPlayer.seek(mediaPlayer.getCurrentTime().multiply(1.5));
            });

            forwardButton.addEventHandler(MouseEvent.MOUSE_ENTERED, (MouseEvent e) -> {
                forwardButton.setStyle("-fx-background-color: Black");
                forwardButton.setStyle("-fx-body-color: Black");
            });
            forwardButton.addEventHandler(MouseEvent.MOUSE_EXITED, (MouseEvent e) -> {
                forwardButton.setStyle("-fx-background-color: Black");
            });




            //Backward Button
            Image backwardButtonImage = new Image("file:///C:/Users/MANJEET SINGH/IdeaProjects/MoviePlayer/buttonImages/backwardbutton.png");
            ImageView ivbackward = new ImageView(backwardButtonImage);
            ivbackward.setFitHeight(25);
            ivbackward.setFitWidth(25);

            final Button backwardButton = new Button();
            backwardButton.setGraphic(ivbackward);
            backwardButton.setStyle("-fx-background-color: Black");

            backwardButton.setOnAction((ActionEvent e) -> {
                mediaPlayer.seek(mediaPlayer.getCurrentTime().multiply(0.5));
            });

            backwardButton.addEventHandler(MouseEvent.MOUSE_ENTERED, (MouseEvent e) -> {
                backwardButton.setStyle("-fx-background-color: Black");
                backwardButton.setStyle("-fx-body-color: Black");
            });
            forwardButton.addEventHandler(MouseEvent.MOUSE_EXITED, (MouseEvent e) -> {
                backwardButton.setStyle("-fx-background-color: Black");
            });


            //Reload Button




            final HBox hbox2 = new HBox();
            final HBox hbox = new HBox();
                    final int bands = mediaPlayer.getAudioSpectrumNumBands();
                    final Rectangle[] rects = new Rectangle[bands];
                    for (int i=0;i<rects.length;i++){
                        rects[i] = new Rectangle();
                        rects[i].setFill(Color.GREENYELLOW);
                        hbox.getChildren().add(rects[i]);
                    }
                    vbox.setSpacing(10);
                    hbox.setPadding(new Insets(2, 20, 0, 0));
                    hbox2.setAlignment(Pos.CENTER);
                    hbox2.getChildren().addAll(backwardButton,playButton,forwardButton);
                    vbox.getChildren().add(hbox2);
                    vbox.getChildren().add(hbox);

                    StackPane stackPane = new StackPane();//added StackPane
                    stackPane.getChildren().add(mediaView);//add MediaView to StackPane root.setBottom(vbox);
                    root.getChildren().add(stackPane);//add StackPane to root(VBox)
                    root.getChildren().add(vbox);
                    Scene scene = new Scene(root, 400, 400, Color.BLACK);

                mediaPlayer.setOnReady(new Runnable() {
                    // run comment
                    @Override
                    public void run() {
                        int w = mediaPlayer.getMedia().getWidth();
                        int h = mediaPlayer.getMedia().getHeight();

                        hbox.setMinWidth(w);
                        int bandwith = w/rects.length;
                        for (Rectangle r:rects){
                            r.setWidth(bandwith);
                            r.setHeight(2);
                        }

                        primaryStage.setMinWidth(w);
                        primaryStage.setMinHeight(h);
                        vbox.setMinSize(w, 100);
                        vbox.setMaxSize(scene.getWidth(), scene.getHeight());
                        vbox.setTranslateY(h-50);

                        slider.setMin(0.0);
                        slider.setValue(0.0);
                        slider.setMax(mediaPlayer.getTotalDuration().toSeconds());


                        Slideout.getKeyFrames().addAll(
                                new KeyFrame(new Duration(0),
                                        new KeyValue(vbox.translateYProperty(),h-100),
                                        new KeyValue(vbox.opacityProperty(), 0.9)
                                ),
                                new KeyFrame(new Duration(300),
                                        new KeyValue(vbox.translateYProperty(),h),
                                        new KeyValue(vbox.opacityProperty(), 0.0)
                                )

                        );

                        Slidein.getKeyFrames().addAll(
                                new KeyFrame(new Duration(0),
                                        new KeyValue(vbox.translateYProperty(),h),
                                        new KeyValue(vbox.opacityProperty(), 0.0)
                                ),
                                new KeyFrame(new Duration(300),
                                        new KeyValue(vbox.translateYProperty(),h-100),
                                        new KeyValue(vbox.opacityProperty(), 0.9)
                                )
                        );



                    }
                });




            //Controllers
            mediaPlayer.currentTimeProperty().addListener(new ChangeListener<Duration>() {
                @Override
                public void changed(ObservableValue<? extends Duration> observable, Duration duration, Duration current) {
                    slider.setValue(current.toSeconds());
                }
            });


            //Slider Click Property
            slider.setOnMouseClicked(new EventHandler<MouseEvent>() {
                @Override
                public void handle(MouseEvent event) {
                    mediaPlayer.seek(Duration.seconds(slider.getValue()));
                }
            });


            //Spectrum Listener
            mediaPlayer.setAudioSpectrumListener(new AudioSpectrumListener() {
                @Override
                public void spectrumDataUpdate(double timestamp, double duration, float[] magnitudes, float[] phases) {
                    for (int i=0; i < rects.length; i++) {
                        double h = magnitudes[i] + 60 ;
                        if(h>2){
                            rects[i].setHeight(h);
                        }
                    }
                }
            });

            return scene;
         }



    @Override
    public void start(Stage primaryStage) throws Exception {

        scene = setScene(this.width, this.height,primaryStage);

        primaryStage.setTitle("Media Player!");
        primaryStage.setScene(scene);
        primaryStage.show();
        //mediaPlayer.play();
    }
}