/* Dummy.java
 * =========================================================================
 * This file is originally part of the JMathTeX Library - http://jmathtex.sourceforge.net
 *
 * Copyright (C) 2004-2007 Universiteit Gent
 * Copyright (C) 2009 DENIZET Calixte
 *
 * 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 2 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.
 *
 * A copy of the GNU General Public License can be found in the file
 * LICENSE.txt provided with the source distribution of this program (see
 * the META-INF directory in the source jar). This license can also be
 * found on the GNU website at http://www.gnu.org/licenses/gpl.html.
 *
 * If you did not receive a copy of the GNU General Public License along
 * with this program, contact the lead developer, or write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * Linking this library statically or dynamically with other modules 
 * is making a combined work based on this library. Thus, the terms 
 * and conditions of the GNU General Public License cover the whole 
 * combination.
 * 
 * As a special exception, the copyright holders of this library give you 
 * permission to link this library with independent modules to produce 
 * an executable, regardless of the license terms of these independent 
 * modules, and to copy and distribute the resulting executable under terms 
 * of your choice, provided that you also meet, for each linked independent 
 * module, the terms and conditions of the license of that module. 
 * An independent module is a module which is not derived from or based 
 * on this library. If you modify this library, you may extend this exception 
 * to your version of the library, but you are not obliged to do so. 
 * If you do not wish to do so, delete this exception statement from your 
 * version.
 * 
 */

package com.himamis.retex.renderer.share;

/**
 * Used by RowAtom. The "textSymbol"-property and the type of an atom can change (according to the
 * TeX-algorithms used). Or this atom can be replaced by a ligature, (if it was a CharAtom). But
 * atoms cannot be changed, otherwise different boxes could be made from the same TeXFormula, and
 * that is not desired! This "dummy atom" makes sure that changes to an atom (during the
 * createBox-method of a RowAtom) will be reset.
 */
public class Dummy {

	private Atom el;

	private boolean textSymbol = false;

	private int type = -1;

	/**
	 * Creates a new Dummy for the given atom.
	 *
	 * @param a an atom
	 */
	public Dummy(Atom a) {
		el = a;
	}

	/**
	 * Changes the type of the atom
	 *
	 * @param t the new type
	 */
	public void setType(int t) {
		type = t;
	}

	/**
	 * Changes the type of the atom
	 *
	 * @param t the new type
	 */
	public int getType() {
		return type;
	}

	/**
	 *
	 * @return the changed type, or the old left type if it hasn't been changed
	 */
	public int getLeftType() {
		return (type >= 0 ? type : el.getLeftType());
	}

	/**
	 *
	 * @return the changed type, or the old right type if it hasn't been changed
	 */
	public int getRightType() {
		return (type >= 0 ? type : el.getRightType());
	}

	public boolean isCharSymbol() {
		return el instanceof CharSymbol;
	}

	public boolean isCharInMathMode() {
		return el instanceof CharAtom && ((CharAtom) el).isMathMode();
	}

	/**
	 * This method will only be called if isCharSymbol returns true.
	 */
	public CharFont getCharFont(TeXFont tf) {
		return ((CharSymbol) el).getCharFont(tf);
	}

	/**
	 * Changes this atom into the given "ligature atom".
	 *
	 * @param a the ligature atom
	 */
	public void changeAtom(FixedCharAtom a) {
		textSymbol = false;
		type = -1;
		el = a;
	}

	public Box createBox(TeXEnvironment rs) {
		if (textSymbol) {
			((CharSymbol) el).markAsTextSymbol();
		}
		Box b = el.createBox(rs);
		if (textSymbol)
		 {
			((CharSymbol) el).removeMark(); // atom remains unchanged!
		}
		return b;
	}

	public void markAsTextSymbol() {
		textSymbol = true;
	}

	public boolean isKern() {
		return el instanceof SpaceAtom;
	}

	// only for Row-elements
	public void setPreviousAtom(Dummy prev) {
		if (el instanceof Row) {
			((Row) el).setPreviousAtom(prev);
		}
	}

	public Atom getAtom() {
		return el;
	}
}