Application: gvSIG desktop » Library: org.gvsig.tools

package org.gvsig.tools.swing.api.documentfilters;

import javax.swing.JTextField;

import javax.swing.text.AttributeSet;

import javax.swing.text.BadLocationException;

import javax.swing.text.Document;

import javax.swing.text.DocumentFilter;

import javax.swing.text.PlainDocument;

/**

 *

 * @author jjdelcerro

 */

public class IntegerDocumentFilter extends DocumentFilter {

    public static void install(JTextField text) {

        Document doc = text.getDocument();

        if (doc instanceof PlainDocument) {

            ((PlainDocument) doc).setDocumentFilter(new IntegerDocumentFilter());

        }

    }

    public static int getValue(JTextField text) {

        String s = text.getText();

        try {

            int n = Integer.parseInt(s);

            return n;

        } catch (Exception ex) {

            return 0;

        }

    }    

    @Override

    public void insertString(FilterBypass fb, int offset, String string,

            AttributeSet attr) throws BadLocationException {

        Document doc = fb.getDocument();

        StringBuilder sb = new StringBuilder();

        sb.append(doc.getText(0, doc.getLength()));

        sb.insert(offset, string);

        String s = sb.toString();

        if (s.length()==0 || test(s)) {

            super.insertString(fb, offset, string, attr);

        } else {

            // warn the user and don't allow the insert

        }

    }

    private boolean test(String text) {

        try {

            Integer.parseInt(text);

            return true;

        } catch (NumberFormatException e) {

            return false;

        }

    }

    @Override

    public void replace(FilterBypass fb, int offset, int length, String text,

            AttributeSet attrs) throws BadLocationException {

        Document doc = fb.getDocument();

        StringBuilder sb = new StringBuilder();

        sb.append(doc.getText(0, doc.getLength()));

        sb.replace(offset, offset + length, text);

        String s = sb.toString();

        if (s.length()==0 || test(s)) {

            super.replace(fb, offset, length, text, attrs);

        } else {

            // warn the user and don't allow the insert

        }

    }

    @Override

    public void remove(FilterBypass fb, int offset, int length)

            throws BadLocationException {

        Document doc = fb.getDocument();

        StringBuilder sb = new StringBuilder();

        sb.append(doc.getText(0, doc.getLength()));

        sb.delete(offset, offset + length);

        String s = sb.toString();

        if (s.length()==0 || test(s)) {

            super.remove(fb, offset, length);

        } else {

            // warn the user and don't allow the insert

        }

    }

}