The bind fuction only works for the initial value - javafx

Question

I an trying to use the fuction 'bind' but it doesn't seem to work. What I want is to bind the position of a 'RectangleFx' (which extends from javafx.scene.shape.Box) to the one of a Rectangle (which is an object) so that if the coordinates of the position of the rectangle change, on the screen the box will move. The problem is that when I use 'bind' it only gives to RectangleFX the initial value of the positione and doesn't update it when I change the one of Rectangle.
The 'Rectangle' class is one I wrote myself, it is not javafx.scene.shape.Rectangle.
public class RectangleFX extends javafx.scene.shape.Box {
private Rectangle rectangle;
public RectangleFX(Rectangle r) {
super(r.getWidth(), r.getHeight(), 30);
this.rectangle = r;
this.translateXProperty().bind(r.getCenter().propertyX());
this.translateYProperty().bind(r.getCenter().propertyY());
}
public Rectangle getRect() {
return this.rectangle;
}
}
public class Rectangle extends Body {
Vec2 min;
Vec2 max;
public Rectangle(Vec2 pos, Vec2 spd, double mass, double density, double rest, Vec2 vel, Vec2 a, Vec2 b) {
super(pos, spd, vel, mass, density, rest);
this.min = a;
this.max = b;
}
public Rectangle(Vec2 pos, double mass, double rest, Vec2 a, Vec2 b) {
super(pos, mass * (b.getX() - a.getX()) * (b.getY() * a.getY()), mass, rest);
this.min = a;
this.max = b;
}
public double get_x_extent() {
return this.max.getX() - this.min.getX();
}
public double get_y_extent() {
return this.max.getY() - this.min.getY();
}
#Override
public double get_min_x() {
return this.min.getX();
}
#Override
public double get_min_y() {
return this.min.getY();
}
#Override
public double get_max_x() {
return this.max.getX();
}
#Override
public double get_max_y() {
return this.max.getY();
}
public double getWidth() {
return Math.abs(this.get_max_x() - this.get_min_x());
}
public double getHeight() {
return Math.abs(this.get_max_y() - this.get_min_y());
}
public Vec2 getCenter() {
return new Vec2(1 / 2 * this.getWidth() + this.getPosition().getX(), 1 / 2 * this.getHeight() + this.getPosition().getY());
}
boolean contact(Rectangle a, Rectangle b) {
if (a.max.getX() < b.min.getX() || a.min.getX() > b.max.getX())
return false;
if (a.max.getY() < b.min.getY() || a.min.getY() > b.max.getY())
return false;
return true;
}
}
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
public class Vec2 {
private DoubleProperty x = new SimpleDoubleProperty();
private DoubleProperty y = new SimpleDoubleProperty();
public double getX() {
return this.x.get();
}
public double getY() {
return this.y.get();
}
public void setX(double value) {
this.x.set(value);
}
public void setY(double value) {
this.y.set(value);
}
public DoubleProperty propertyX() {
return this.x;
}
public DoubleProperty propertyY() {
return this.y;
}
public Vec2(double x, double y) {
this.setX(x);
this.setY(y);
}
public static final Vec2 null_Vector = new Vec2(0, 0);
public static final Vec2 x_Vector = new Vec2(1, 0);
public static final Vec2 y_Vector = new Vec2(0, 1);
public static Vec2 addition(Vec2 v1, Vec2 v2) {
return new Vec2(v1.getX() + v2.getX(), v1.getY() + v2.getY());
}
public void increase_by(Vec2 v) {
this.setX(this.getX() + v.getX());
this.setY(this.getY() + v.getY());
}
public static Vec2 substraction(Vec2 v1, Vec2 v2) {
return new Vec2(v1.getX() - v2.getX(), v1.getY() - v2.getY());
}
public void decrease_by(Vec2 v) {
this.setX(this.getX() - v.getX());
this.setY(this.getY() - v.getY());
}
public static Vec2 product(Vec2 v1, Vec2 v2) {
return new Vec2(v1.getX() * v2.getX(), v1.getY() * v2.getY());
}
public static Vec2 product(double d, Vec2 v) {
return new Vec2(d * v.getX(), d * v.getY());
}
public void multiply_by(Vec2 v) {
this.setX(this.getX() * v.getX());
this.setY(this.getY() * v.getY());
}
public void multiply_by(double d) {
this.setX(this.getX() * d);
this.setY(this.getY() * d);
}
public static Vec2 division(Vec2 v1, Vec2 v2) {
return new Vec2(v1.getX() / v2.getX(), v1.getY() / v2.getY());
}
public static Vec2 division(double d, Vec2 v) {
if (d == 0)
throw new ArithmeticException();
return new Vec2(v.getX() / d, v.getY() / d);
}
public static Vec2 opposite(Vec2 v) {
return new Vec2(-v.getX(), -v.getY());
}
public static Vec2 invert(Vec2 v) {
return new Vec2(1 / v.getX(), 1 / v.getY());
}
public double length() {
return Math.sqrt(this.length_Squared());
}
public double length_Squared() {
return (dot_Product(this, this));
}
public Vec2 copy() {
return new Vec2(this.getX(), this.getY());
}
public static boolean compare(Vec2 v1, Vec2 v2) {
if (v1 == null) {
if (v2 == null)
return true;
return false;
} else if (v2 == null)
return false;
if (v1.getX() != v2.getX())
return false;
if (v1.getY() != v2.getY())
return false;
return true;
}
public static double dot_Product(Vec2 v1, Vec2 v2) {
return (v1.getX() * v2.getX() + v1.getY() * v2.getY());
}
public static double cross_Product(Vec2 v1, Vec2 v2) {
return (v1.getX() * v2.getY() - v1.getY() * v2.getX());
}
public static Vec2 cross_Product(Vec2 v, double d) {
return new Vec2(d * v.getY(), -d * v.getX());
}
public static Vec2 cross_Product(double d, Vec2 v) {
return new Vec2(-d * v.getY(), d * v.getX());
}
public static boolean isNull(Vec2 v) {
if (v.getX() != 0)
return false;
if (v.getY() != 0)
return false;
return true;
}
public void normalize() {
double d = length_Squared();
this.setX(this.getX() / d);
this.setY(this.getY() / d);
}
public Vec2 projection_on(Vec2 v) {
return Vec2.substraction(this, Vec2.product(Vec2.dot_Product(this, v), this));
}
public Vec2 symetric_on(Vec2 v) {
return Vec2.substraction(Vec2.product(2, this.projection_on(v)), this);
}
}
Here is an example of code that does not work, when we press NUMPAD0 the cube should move on the screen since the coordinates of the center of the rectangle to which it is bound change.
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.Camera;
import javafx.scene.Group;
import javafx.scene.PerspectiveCamera;
import javafx.scene.Scene;
import javafx.scene.input.KeyEvent;
import javafx.scene.paint.Color;
public class Main extends Application {
private final double HEIGHT = 800;
private final double WIDTH = 1400;
#Override
public void start(Stage primaryStage) throws Exception {
Vec2 posb = new Vec2(1000, 700);
Vec2 minb = new Vec2(30, 0);
Vec2 maxb = new Vec2(0, 30);
Rectangle r = new Rectangle(posb, 30, 10, minb, maxb);
RectangleFX b = new RectangleFX(r);
Group boxG = new Group();
boxG.getChildren().add(b);
Group root = new Group(boxG);
Camera cam = new PerspectiveCamera();
Scene scene = new Scene(root, WIDTH, HEIGHT);
scene.setFill(Color.BLACK);
scene.setCamera(cam);
primaryStage.setTitle("Test position");
primaryStage.setScene(scene);
primaryStage.show();
primaryStage.addEventHandler(KeyEvent.KEY_PRESSED, event -> {
switch (event.getCode()) {
case NUMPAD0:
r.getPosition().setX(r.getPosition().getX() + 10);
break;
default:
break;
}
});
System.out.println("test");
}
public static void main(String[] args) {
launch(args);
}
}

Answer 1

I found the problem. I was just binding the wrong values...