/*
 * DSI utilities
 *
 * Copyright (C) 2005-2020 Sebastiano Vigna
 *
 *  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Lesser General Public License as published by the Free
 *  Software Foundation; either version 3 of the License, or (at your option)
 *  any later version.
 *
 *  This library 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 Lesser General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 */

package it.unimi.dsi.parser.callback;

import java.util.Map;

import it.unimi.dsi.lang.MutableString;
import it.unimi.dsi.parser.Attribute;
import it.unimi.dsi.parser.BulletParser;
import it.unimi.dsi.parser.Element;

/**
 * A default, do-nothing-at-all callback.
 *
 * <P>Callbacks can inherit from this class and forget about methods they are not interested in.
 *
 * <P>This class has a protected constructor. If you need an instance of this class, use
 * {@link #getInstance()}.
 */
public class DefaultCallback implements Callback {
	private static final DefaultCallback SINGLETON = new DefaultCallback();

	protected DefaultCallback() {}

	/**
	 * Returns the singleton instance of the default callback.
	 *
	 * @return the singleton instance of the default callback.
	 */
	public static DefaultCallback getInstance() {
		return SINGLETON;
	}

	@Override
	public void configure(final BulletParser parserUnused) {}

	@Override
	public void startDocument() {}

	@Override
	public boolean startElement(final Element elementUnused, final Map<Attribute,MutableString> attrMapUnused) {
		return true;
	}

	@Override
	public boolean endElement(final Element elementUnused) {
		return true;
	}

	@Override
	public boolean characters(final char[] textUnused, final int offsetUnused, final int lengthUnused, final boolean flowBrokenUnused) {
		return true;
	}

	@Override
	public boolean cdata(final Element elementUnused, final char[] textUnused, final int offsetUnused, final int lengthUnused) {
		return true;
	}

	@Override
	public void endDocument() {}
}
