NumericDocumentFilter.java

/*
 *  Copyright (C) 2010 Dav
 * 
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.rubikscomplex.ufosge.gui;

import java.awt.Toolkit;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;
import javax.swing.text.DocumentFilter.FilterBypass;


/**
 *
 * @author Dav
 */
public class NumericDocumentFilter extends DocumentFilter {
    long minValue;
    long maxValue;

    public NumericDocumentFilter(long minValue, long maxValue) {
        super();
        
        this.minValue = minValue;
        this.maxValue = maxValue;
    }

    @Override
    public void insertString(FilterBypass fb, int offs,
                             String str, AttributeSet a)
        throws BadLocationException {

        System.out.println("[NumericDocumentFilter] insert()");

        try {
            Long.parseLong(str);
        }
        catch (NumberFormatException e) {
            Toolkit.getDefaultToolkit().beep();
            return;
        }
        
        String docText = fb.getDocument().getText(0, fb.getDocument().getLength());
        String preText = docText.substring(0, offs);
        String postText = docText.substring(offs);
        
        String finalText = preText + str + postText;

        long numericValue = Long.parseLong(finalText);

        if (numericValue >= minValue && numericValue <= maxValue) {
            super.insertString(fb, offs, str, a);
        }
        else {
            Toolkit.getDefaultToolkit().beep();
        }
    }

    @Override
    public void replace(FilterBypass fb, int offs,
                        int length,
                        String str, AttributeSet a)
        throws BadLocationException {

        System.out.println("[NumericDocumentFilter] replace()");

        try {
            Long.parseLong(str);
        }
        catch (NumberFormatException e) {
            Toolkit.getDefaultToolkit().beep();
            return;
        }

        String docText = fb.getDocument().getText(0, fb.getDocument().getLength());

        String preStr = docText.substring(0, offs);
        String postStr = docText.substring(offs + length);

        String newStr = preStr + str + postStr;

        if (newStr.length() == 0) {
            super.replace(fb, 0, docText.length(), "0" , a);
            return;
        }

        try {
            long numericValue = Long.parseLong(newStr);

            if (numericValue >= minValue && numericValue <= maxValue) {
                super.replace(fb, offs, length, str, a);
            }
            else {
                Toolkit.getDefaultToolkit().beep();
            }
        }
        catch (NumberFormatException e) {
            Toolkit.getDefaultToolkit().beep();
        }
    }

    public void remove(DocumentFilter.FilterBypass fb,
                       int offs,
                       int length)
        throws BadLocationException {

        System.out.println("[NumericDocumentFilter] remove()");

        String docText = fb.getDocument().getText(0, fb.getDocument().getLength());
        String newStr = docText.substring(0, offs) + docText.substring(offs + length);

        if (newStr.length() == 0) {
            // System.out.println("  : calling replace() instead.");
            fb.replace(0, docText.length(), "0", null);
            
            if (docText.length() == 0) {
                Toolkit.getDefaultToolkit().beep();
            }

            return;
        }

        try {
            long numericValue = Long.parseLong(newStr);

            if (numericValue >= minValue && numericValue <= maxValue) {
                super.remove(fb, offs, length);
            }
            else {
                Toolkit.getDefaultToolkit().beep();
            }
        }
        catch (NumberFormatException e) {
            Toolkit.getDefaultToolkit().beep();
        }
    }
}