Chapter 16 Exercise 5, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

16.5  (Convert numbers)
Write a program that converts between decimal, hex, and binary numbers,
as shown in Figure 16.37c. When you enter a decimal value in the decimal- value
text field and press the Enter key, its corresponding hex and binary numbers
are displayed in the other two text fields. Likewise, you can enter values in
the other fields and convert them accordingly.(Hint:Use the Integer.parseInt(s, radix)
method to parse a string to a decimal and use Integer.toHexString(decimal)
and Integer.toBinaryString(decimal) to obtain a hex number or a binary
number from a decimal.)

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;

public class Exercise_05 extends Application {

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

        DecHexBinaryPane pane = new DecHexBinaryPane();

        primaryStage.setTitle("Decimal - Hex - Binary Calculator");
        primaryStage.setScene(new Scene(pane));
        primaryStage.show();
    }

    private class DecHexBinaryPane extends GridPane {

        Label lblDecimal = new Label("Decimal:");
        Label lblHex = new Label("Hex:");
        Label lblBinary = new Label("Binary:");

        TextField tfDecimal = new TextField();
        TextField tfHex = new TextField();
        TextField tfBinary = new TextField();

        Integer integer = 0;

        private DecHexBinaryPane() {

            setHgap(10);
            setVgap(10);
            setPadding(new Insets(10, 10, 10, 10));

            TextField[] textFields = new TextField[3];
            // row 0
            add(lblDecimal, 0, 0);
            add(tfDecimal, 1, 0);
            textFields[0] = tfDecimal;
            // row 1
            add(lblHex, 0, 1);
            add(tfHex, 1, 1);
            textFields[1] = tfHex;

            // row 2
            add(lblBinary, 0, 2);
            add(tfBinary, 1, 2);
            textFields[2] = tfBinary;

            for (int i = 0; i < textFields.length; i++) {
                textFields[i].setText("0");
                textFields[i].setAlignment(Pos.CENTER_RIGHT);

            }

            tfDecimal.setOnAction(e -> {
                integer = new Integer(tfDecimal.getText());
                update();
            });
            tfHex.setOnAction(e -> {
                integer = Integer.parseInt(tfHex.getText(), 16);
                update();
            });

            tfBinary.setOnAction(e-> {
                integer = Integer.parseInt(tfBinary.getText(), 2);
                update();
            });


        }

        private void update() {
            tfDecimal.setText(integer.toString());
            tfHex.setText(Integer.toHexString(integer));
            tfBinary.setText(Integer.toBinaryString(integer));
        }
    }




    public static void main(String[] args) {
        Application.launch(args);
    }
}