public NumberChooser() 
{
        setLayout (new BorderLayout ());
        JPanel buttons = new JPanel(new GridLayout(0, 1));
        down = new ArrowButton(ArrowButton.DOWN);
        down.addActionListener (this);
        add (field = new JTextField(4), BorderLayout.CENTER);
        field.addActionListener (this);
        up = new ArrowButton(ArrowButton.UP);
        up.addActionListener (this);
        buttons.add (up);
        buttons.add (down);
        add(buttons, BorderLayout.EAST);
}

 public NumberChooser(int min,
    int max,
    int value) 
{
        this();
        setMinimum(min);
        setMaximum(max);
        setValue(value);
}

 public synchronized  void actionPerformed(ActionEvent e) 
{
        int value = getValue ();
        if (e.getSource () == down) {
            if (value  > minimum) {
                value = (value - step  > value) ? minimum : clamp (value - step);
                setValue (value);
                fireValueChange (value);
            }
        } else if (e.getSource () == up) {
            if (value <  maximum) {
                value = (value + step <  value) ? maximum : clamp (value + step);
                setValue (value);
                fireValueChange (value);
            }
        } else if (e.getSource () == field) {
            try {
                int v = Integer.parseInt (e.getActionCommand ());
                if ((v <  minimum) || (v  > maximum))
                    getToolkit ().beep ();
                else
                    fireValueChange (v);
            } catch (NumberFormatException ex) {
                getToolkit ().beep ();
            }
        }
}

 public  void addPropertyChangeListener(PropertyChangeListener l) 
{
         
        listeners.addPropertyChangeListener (l);
}

 protected int clamp(int v) 
{
        return Math.max (minimum, Math.min (maximum, v));
}

 protected  void fireValueChange(int v) 
{
         
        listeners.firePropertyChange ("value", oValue, 
                                      oValue = new Integer (v));
}

 public int getColumns() 
{
        return field.getColumns ();
}

 public int getMaximum() 
{
        return maximum;
}

 public int getMinimum() 
{
        return minimum;
}

 public int getStep() 
{
        return step;
}

 public int getValue() 
{
        try {
            return clamp (Integer.parseInt (field.getText ()));
        } catch (NumberFormatException ex) {
            return clamp (0);
        }
}

 public static  void main(String[] args) 
{
        try {
            final JFrame frame = new JFrame("NumberChooser unit test");
            frame.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {
                    Window w = e.getWindow();
                    w.setVisible(false);
                    w.dispose();
                    System.exit(0);
                }
            });
            JPanel panel = new JPanel(new GridLayout(0, 1));
            final JLabel label = new JLabel("Enter a value");
            NumberChooser chooser = new NumberChooser();
            panel.add(label);
            panel.add(chooser);
            chooser.addPropertyChangeListener(new PropertyChangeListener() {
                public void propertyChange(PropertyChangeEvent ev) {
                    System.out.println(((Integer)ev.getNewValue()).intValue());
                }
            });
            frame.getContentPane().add(panel);
            frame.pack();
            frame.setVisible(true);
        }
        catch (Exception exc) {
            System.out.println("Exception: " + exc.getMessage());
            exc.printStackTrace();
            System.exit(1);
        }
}

 public  void removePropertyChangeListener(PropertyChangeListener l) 
{
        listeners.removePropertyChangeListener (l);
}

 public  void requestFocus() 
{
        field.requestFocus ();
}

 public  void setColumns(int c) 
{
        field.setColumns (c);
}

 public synchronized  void setMaximum(int m) 
{
  
        maximum = m;
}

 public synchronized  void setMinimum(int m) 
{
  
        minimum = m;
}

 public synchronized  void setStep(int s) 
{
  
        if (s < = 0)
            throw new IllegalArgumentException ("Step too small (" + s + ").");
        step = s;
}

 public synchronized  void setValue(int v) 
{
        field.setText (String.valueOf (v));
        fireValueChange (getValue ());
}