TextLimitDocument.java

package com.mattc.autotyper.gui;

import com.mattc.autotyper.meta.SwingCompatible;

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

/**
 * A Document designed to set a character limit on Text Input Components (e.g.
 * JTextField, JTextArea, etc.) using the JTextComponent.setDocument method.
 *
 * @author Matthew
 */
@SwingCompatible
public class TextLimitDocument extends PlainDocument {

    private static final long serialVersionUID = 2050611792142151267L;

    private int limit;

    public TextLimitDocument(int limit) {
        this.limit = limit;
    }

    public void setLimit(int limit) {
        this.limit = limit;
    }

    public int getLimit() {
        return this.limit;
    }

    @Override
    public void insertString(int offs, String str, AttributeSet a) throws BadLocationException {
        if (str == null) return;

        if ((getLength() + str.length()) <= this.limit) {
            super.insertString(offs, str, a);
        }
    }

}