/* OverUnderDelimiter.java
 * =========================================================================
 * This file is originally part of the JMathTeX Library - http://jmathtex.sourceforge.net
 * 
 * Copyright (C) 2004-2007 Universiteit Gent
 * Copyright (C) 2009-2010 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;

import com.himamis.retex.renderer.share.exception.InvalidUnitException;

/**
 * A box representing another atom with a delimiter and a script above or under it, with script and
 * delimiter seperated by a kern.
 */
public class OverUnderDelimiter extends Atom {

	// base and script atom
	private final Atom base;
	private Atom script;

	// delimiter symbol
	private final SymbolAtom symbol;

	// kern between delimiter and script
	private final SpaceAtom kern;

	// whether the delimiter should be positioned above or under the base
	private final boolean over;

	@Override
	final public Atom duplicate() {
		return setFields(new OverUnderDelimiter(base, script,symbol, kern, over));
	}

	public OverUnderDelimiter(Atom base, Atom script, SymbolAtom s, int kernUnit, double kern, boolean over)
			throws InvalidUnitException {
		type = TeXConstants.TYPE_INNER;
		this.base = base;
		this.script = script;
		symbol = s;
		this.kern = new SpaceAtom(kernUnit, 0, kern, 0);
		this.over = over;
	}

	private OverUnderDelimiter(Atom base, Atom script, SymbolAtom s, SpaceAtom kern, boolean over)
			throws InvalidUnitException {
		type = TeXConstants.TYPE_INNER;
		this.base = base;
		this.script = script;
		symbol = s;
		this.kern = kern;
		this.over = over;
	}

	public void addScript(Atom script) {
		this.script = script;
	}

	public boolean isOver() {
		return over;
	}

	@Override
	public Box createBox(TeXEnvironment env) {
		Box b = (base == null ? new StrutBox(0, 0, 0, 0) : base.createBox(env));
		Box del = DelimiterFactory.create(symbol.getName(), env, b.getWidth());

		Box scriptBox = null;
		if (script != null) {
			scriptBox = script.createBox((over ? env.supStyle() : env.subStyle()));
		}

		// create centered horizontal box if smaller than maximum width
		double max = getMaxWidth(b, del, scriptBox);
		if (max - b.getWidth() > TeXFormula.PREC) {
			b = new HorizontalBox(b, max, TeXConstants.ALIGN_CENTER);
		}

		del = new VerticalBox(del, max, TeXConstants.ALIGN_CENTER);
		if (scriptBox != null && max - scriptBox.getWidth() > TeXFormula.PREC) {
			scriptBox = new HorizontalBox(scriptBox, max, TeXConstants.ALIGN_CENTER);
		}

		return new OverUnderBox(b, del, scriptBox, kern.createBox(env).getHeight(), over);
	}

	private static double getMaxWidth(Box b, Box del, Box script) {
		double max = Math.max(b.getWidth(), del.getHeight() + del.getDepth());
		if (script != null) {
			max = Math.max(max, script.getWidth());
		}

		return max;
	}
}