Creating Custom Spinner Model

Question

I'm trying to create a custom JSpinner that represents a sequence of numbers of power 2. Like, 1-2-4-8-16 and so on. I have to do that with extending AbstractSpinnerModel and changing its implemented methods (getNextValue etc.). The problem is, the arrow keys on my custom JSpinner don't work. Nothing changes when I click one of them. I need to show previous and next values of current value. ( Previous value = 4 Current Value = 8 Next Value = 16 ).

Here is my code :

import java.awt.*;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Hw5SpinnerModel extends JFrame {

public static void main(String[] args) {

    Hw5SpinnerModel frame = new Hw5SpinnerModel();

}

public Hw5SpinnerModel() {

    setTitle("Hw5SpinnerModel");
    setSize(350, 300);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    final JSpinner jspn = new JSpinner(new CustomSpinnerModel());

    final JLabel jlbl = new JLabel("");

    add(jspn, BorderLayout.NORTH);
    add(jlbl, BorderLayout.CENTER);

    jspn.addChangeListener(new ChangeListener() {

        @Override
        public void stateChanged(ChangeEvent e) {

            jlbl.setText(jspn.getPreviousValue() + jspn.getValue() + jspn.getNextValue());

        }

    });

    //jlbl.setText(jspn.getNextValue() + "");

    setVisible(true);

}

public class CustomSpinnerModel extends AbstractSpinnerModel {

    Integer i = 1;

    @Override
    public Object getValue() {
        return i;
    }

    @Override
    public void setValue(Object value) {
        i = (Integer) value;
    }

    @Override
    public Object getNextValue() {
        return 2 * i;
    }

    @Override
    public Object getPreviousValue() {
        return i / 2;
    }

}

}

Any help will be appreciated.

Answer 1

    jSpinner1.setModel(new SpinnerNumberModel(1, null, null, 1) {
        @Override
        public Object getNextValue() {                
            Object nextValue = super.getValue();
            int x = Integer.valueOf(nextValue.toString())*2;
            //Object o = x;
            return x;
        }
    });

It works 100%