How to set numeric filter for JSpinner?

Question

Hi there,
I searched the forum but can't find a solution...I'm kind of getting mad!
Problem is: I have a JSpinner, I must prevent the user to insert any non-numeric value. the accepted input should be in the form <n>.<m>
where n could be any integer number, m is OPTIONAL and could be a single digit number. Example: 150.2 or 41 or 7.1 etc.
I set a DocumentFilter on the editor of JSpinner, overriding replace method. Problem is replace method is never called so my filter is not applied and the user is allowed to insert whatever he wants, characters included.
Here's my code (sorry for the horrible gui, but it's just for some testing.):
import java.awt.Dimension;
import java.util.regex.Pattern;
import javax.swing.JFrame;
import javax.swing.JSpinner;
import javax.swing.JTextField;
import javax.swing.SpinnerNumberModel;
import javax.swing.JSpinner.NumberEditor;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;
public class SpinnerTry {
     public final static String REGEX_DOUBLE_NUMBER = "^([0-9]+)(\\.(\\d{1})?)?$";
     private static final Double MIN_PW = 12.0;
     private static final Double MAX_PW = 19.0;
     private static final Double DEFAULT = 15.0;
     private static final Double STEP = 1.00;
     private static final SpinnerNumberModel model = new SpinnerNumberModel(
               DEFAULT, // initial value
               MIN_PW, // min
               MAX_PW, // max
               STEP);
     public static void main(String[] args) {
          JFrame frame = new JFrame();
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          JSpinner spinner = new JSpinner(model);
          spinner.setPreferredSize(new Dimension(50, 15));
          NumberEditor edit = new NumberEditor(spinner, "#######.#");
          spinner.setEditor(edit);
          JTextField textField = ((JSpinner.DefaultEditor) spinner.getEditor()).getTextField();
          ((AbstractDocument) textField.getDocument()).setDocumentFilter(new MyDocumentFilter());
          frame.getContentPane().add(spinner);
          frame.setSize(new Dimension(200, 200));
          frame.setVisible(true);
     static class MyDocumentFilter extends DocumentFilter {
          public void replace(FilterBypass fb, int offset, int length, String text,
                    AttributeSet attrs) throws BadLocationException {
               System.out.println("Called replace");
               String mytext = fb.getDocument().getText(0, offset);
               mytext += text;
               if (fb.getDocument().getLength() - 1 > offset) {
                    mytext += fb.getDocument().getText(offset + 1,
                              fb.getDocument().getLength() - offset);
               boolean ok = true;
               ok = Pattern.matches(REGEX_DOUBLE_NUMBER, mytext);
               if (ok)
                    super.replace(fb, offset, length, text, attrs);
          public void insertString(FilterBypass fb, int offset, String string, AttributeSet attr)
                    throws BadLocationException {
               if (Pattern.matches(REGEX_DOUBLE_NUMBER, string)) {
                    super.insertString(fb, offset, string, attr);
}Why replace method is not called when inserting somethig into the spinner text field?
Thanks a lot in advance.
Paul
Edited by: the.paul on Jul 27, 2010 1:11 AM

Answer 1

I found a solution, got inspiration from [http://forums.sun.com/thread.jspa?forumID=57&threadID=5424330] .
Code:
import java.awt.Dimension;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.regex.Pattern;
import javax.swing.JFrame;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.JSpinner.NumberEditor;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultFormatterFactory;
import javax.swing.text.DocumentFilter;
import javax.swing.text.NumberFormatter;
public class SpinnerTry {
     public final static String REGEX_DOUBLE_NUMBER = "^([0-9]+)(\\.(\\d{1})?)?$";
     private static final Double MIN_PW = 12.0;
     private static final Double MAX_PW = 19.0;
     private static final Double DEFAULT = 15.0;
     private static final Double STEP = 1.00;
     private static final SpinnerNumberModel model = new SpinnerNumberModel(
               DEFAULT, // initial value
               MIN_PW, // min
               MAX_PW, // max
               STEP);
     public static void main(String[] args) {
          JFrame frame = new JFrame();
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          JSpinner spinner = new JSpinner(model);
          spinner.setPreferredSize(new Dimension(50, 15));
          String decimalFormatPattern = "#######.#";
          NumberEditor edit = new NumberEditor(spinner);
          spinner.setEditor(edit);
          ((NumberEditor) spinner.getEditor()).getTextField().setFormatterFactory(
                new DefaultFormatterFactory(new MyListFormatter(model, new DecimalFormat(decimalFormatPattern))));
          frame.getContentPane().add(spinner);
          frame.setSize(new Dimension(200, 200));
          frame.setVisible(true);
     static class MyListFormatter extends NumberFormatter {
          private static final long serialVersionUID = -790552903800038787L;
          private final SpinnerNumberModel model;
          private DocumentFilter filter;
          MyListFormatter(SpinnerNumberModel model, NumberFormat format) {
               super(format);
               this.model = model;
               setValueClass(model.getValue().getClass());
          public void setMinimum(Comparable min) {
               model.setMinimum(min);
          public Comparable getMinimum() {
               return model.getMinimum();
          public void setMaximum(Comparable max) {
               model.setMaximum(max);
          public Comparable getMaximum() {
               return model.getMaximum();
          protected DocumentFilter getDocumentFilter() {
               if (filter == null) {
                    filter = new MyDocumentFilter();
               return filter;
     static class MyDocumentFilter extends DocumentFilter {
          public void replace(FilterBypass fb, int offset, int length, String text,
                    AttributeSet attrs) throws BadLocationException {
               System.out.println("Called replace");
               String mytext = fb.getDocument().getText(0, offset);
               mytext += text;
               if (fb.getDocument().getLength() - 1 > offset) {
                    mytext += fb.getDocument().getText(offset + 1,
                              fb.getDocument().getLength() - offset);
               boolean ok = true;
               ok = Pattern.matches(REGEX_DOUBLE_NUMBER, mytext);
               if (ok)
                    super.replace(fb, offset, length, text, attrs);
          public void insertString(FilterBypass fb, int offset, String string, AttributeSet attr)
                    throws BadLocationException {
               if (Pattern.matches(REGEX_DOUBLE_NUMBER, string)) {
                    super.insertString(fb, offset, string, attr);
}That is: define a custom formatter ; the formatter uses the custom DocumentFilter.
Hope it is useful for some people out there.
Regards