38. Fluent API 2

There are two sliders controlling value of x and y. The values are bound to label 1 (lab1) and 2 (lab2).

We bind the expression f(x,y) = 1/2 *x^2*y^2. The resulting value of f(x,y) is bound to label 3 (lab3).

---

package ex38;
 
import javafx.application.Application;
import javafx.beans.binding.DoubleBinding;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.Slider;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
 
public class Ex38 extends Application {
 
    @Override
    public void start(Stage primaryStage) {
 
        Slider s1 = new Slider(0,10,5);
        Slider s2 = new Slider(0,10,5);
        
        Label lab1 = new Label();
        Label lab2 = new Label();
        Label lab3 = new Label();
        
        lab1.textProperty().bind(
                new SimpleStringProperty("x: ")
                        .concat(s1.valueProperty().asString()));
        
        lab2.textProperty().bind(
                new SimpleStringProperty("y: ")
                        .concat(s2.valueProperty().asString()));
        
        DoubleProperty x = s1.valueProperty();
        DoubleProperty y = s2.valueProperty();
        DoubleBinding sum = x
                .multiply(x)
                .multiply(y)
                .multiply(y)
                .multiply(0.5);
        
        lab3.textProperty().bind(new SimpleStringProperty("f(x,y): ")
                .concat(sum.asString()));        
        
        VBox root = new VBox(50, s1, lab1, s2, lab2, lab3);
        root.setPadding(new Insets(50));
        root.setSpacing(50);
        root.setAlignment(Pos.CENTER);
        root.setStyle("-fx-font-size: 16pt;"
                + "-fx-background-color: darkorange;");
        
        Scene scene = new Scene(root, 400, 400);
        
        primaryStage.setTitle("Example 38. Fluent API 2");
        primaryStage.setScene(scene);
        primaryStage.show();
    }
 
    public static void main(String[] args) {
        launch(args);
    }
}

---

This is the output for x and y of 5:

---