JTextFieldLimit.java

package notwa.gui.components;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;

public class JTextFieldLimit extends PlainDocument {
    private int max = 10;
    
    public JTextFieldLimit(int max)
    {
        this.max = max;
    }
    
    @Override
    public void insertString(int offs, String str, AttributeSet a) throws BadLocationException
    {
        if (getLength() + str.length() > max)
        {
            str = str.substring(0, max - getLength());
        }
        
        super.insertString(offs, str, a);
    }
}