Display variable value in text javafx

Question

This is my first question and I am new in programming. I hope this question will not be boring for you.

I am writing a version of the Snake game in java for a school project. I am using javafx.

Each time the head eats the apple, a text appears and fades away. This text includes the score (increment of apples eaten).

The text appears and fades away well, but the score always shows the value "0", although its value is not 0 (I can see by printing the score in the console).

I have tried to create a class IntValue to call the value of the score in another way but it did not work.

public class MainGame extends Application {

    Snake snake = new Snake();
    Apple apple = new Apple();
    public static final int width = 200;
    public static final int height = 200;
    public static int score;
    private Text tEat = new Text();

public void start(Stage primaryStage) {

    Pane layout = new Pane();
    ObservableList<Node> components = layout.getChildren(); //creates a list of nodes and adds them to pane

    components.add(snake); //snake added to pane
    components.add(apple); //apple added to pane
    components.add(tEat); //text added to pane
    tEat.setText("GG! " + score);
    tEat.setFont(Font.font(STYLESHEET_MODENA, FontWeight.BOLD, 20));
    tEat.setY(height/2);
    tEat.setX(width/2 - 40);
    tEat.setFill(Color.GREEN);
    tEat.setOpacity(0);

Timeline timeline = new Timeline(new KeyFrame(Duration.millis(100), ev -> {
        snake.move();

        if (snake.collides(apple)) {
            score++; //score is incremented but not updated in tEat
            fader(tEat); //tEat text appears and fades away
            snake.eat(apple);
            components.remove(apple);
            apple = new Apple();
            components.add(apple);
        }
    }));
    timeline.setCycleCount(Animation.INDEFINITE);
    timeline.play();

purring pigeon · Accepted Answer · 2015-12-29 17:03:42Z

2

You can create a binding and it will update automatically.

Create:

private LongProperty score = new SimpleLongProperty(0);

Then create a binding.

Instead of:

tEat.setText("GG! " + score);

Use this:

tEat.textProperty().bind(Bindings.createStringBinding(() -> ("GG! " + score.get(), score));

Instead of this:

score++;

Use this:

score.set(score.get() + 1);

This will bind your value so that anytime that property is updated, it will update.

answered Dec 29, 2015 at 17:03

purring pigeon

4,2096 gold badges38 silver badges72 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Stephane B. Over a year ago

Thanks it works. Someone gave me also another solution which is to place tEat.setText("GG! " + score); inside if (snake.collides(apple)) { block.

purring pigeon Over a year ago

That works as well. But with the binding if you update score from other places it will update as well. So you don't need to have that code everywhere.

Collectives™ on Stack Overflow

Display variable value in text javafx

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related