JFormattedTextField issues

1. On Mac OS, the default behavior of the UI delegate, com.apple.laf.AquaTextFieldF, is similar to CaretPositionListener:

   • Tab or Shift–Tab: place the caret at the beginning of the field.

   • Click: briefly place the caret at the beginning of the field and then move it to the click point.

   IMO, the CaretPositionListener does the latter much more smoothly.

2. The default behavior of JFormattedTextField on focus lost is COMMIT_OR_REVERT. In the example below, Tab though the first, invalid field to see the effect. The formatter can neither commit nor revert to the invalid value, so it substitutes MASK.length() spaces. This value is valid, if a little obscure.

Addendum: I’ve updated the code below to allow changing the setFocusLostBehavior().

Code:

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.text.MaskFormatter;

/** @see http://stackoverflow.com/questions/7378821 */
public class TrashTest {

    private static final String MASK = "########";
    private static final String DEFAULT = "01234567";
    private static final String BOGUS = "0123456";
    private JFormattedTextField jtf1 = createField();
    private JFormattedTextField jtf2 = createField();
    private JFormattedTextField jtf3 = createField();
    private JFormattedTextField jtf4 = createField();
    private JButton reset = new JButton("Reset to Default");
    private JComboBox combo = new JComboBox();
    private JFrame frame = new JFrame("Text Test");

    public TrashTest() {
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocation(150, 150);
        frame.setLayout(new GridLayout(0, 1));
        frame.add(reset);
        frame.add(jtf1);
        frame.add(jtf2);
        frame.add(jtf3);
        frame.add(jtf4);
        frame.add(combo);
        this.initFields();
        reset.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                initFields();
            }
        });
        for (Edit e : Edit.values()) {
            combo.addItem(e);
        }
        combo.setSelectedIndex(jtf1.getFocusLostBehavior());
        combo.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                Edit current = (Edit) combo.getSelectedItem();
                jtf1.setFocusLostBehavior(current.value);
            }
        });
        frame.pack();
        frame.setVisible(true);
    }

    private void initFields() {
        jtf1.setText(BOGUS);
        jtf2.setText(DEFAULT);
        jtf3.setText(DEFAULT);
        jtf4.setText(DEFAULT);
    }

    protected JFormattedTextField createField() {
        MaskFormatter formatter = null;
        try {
            formatter = new MaskFormatter(MASK);
        } catch (java.text.ParseException e) {
            e.printStackTrace(System.out);
        }
        JFormattedTextField jtf = new JFormattedTextField(formatter);
        return jtf;
    }

    enum Edit {

        COMMIT(JFormattedTextField.COMMIT),
        COMMIT_OR_REVERT(JFormattedTextField.COMMIT_OR_REVERT),
        REVERT(JFormattedTextField.REVERT),
        PERSIST(JFormattedTextField.PERSIST);
        private int value;

        private Edit(int n) {
            this.value = n;
        }

        public static Edit getEnum(int n) {
            for (Edit e : Edit.values()) {
                if (e.value == n) {
                    return e;
                }
            }
            return Edit.COMMIT_OR_REVERT;
        }
    }

    public static void main(String[] args) {
        TrashTest textTest = new TrashTest();
    }
}