BaseFillComponent.java

/*
 * JasperReports - Free Java Reporting Library.
 * Copyright (C) 2001 - 2009 Jaspersoft Corporation. All rights reserved.
 * http://www.jaspersoft.com
 *
 * Unless you have purchased a commercial license agreement from Jaspersoft,
 * the following license terms apply:
 *
 * This program is part of JasperReports.
 *
 * JasperReports 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.
 *
 * JasperReports 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 JasperReports. If not, see <http://www.gnu.org/licenses/>.
 */
package net.sf.jasperreports.engine.component;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRExpression;
import net.sf.jasperreports.engine.JRPrintElement;


/**
 * A base abstract implementation of a fill component.
 * 
 * @author Lucian Chirita (lucianc@users.sourceforge.net)
 * @version $Id: BaseFillComponent.java 3033 2009-08-27 11:46:22Z teodord $
 */
public abstract class BaseFillComponent implements FillComponent
{

	/**
	 * The fill context, as set by {@link #initialize(FillContext)}.
	 */
	protected FillContext fillContext;
	
	public void initialize(FillContext fillContext)
	{
		this.fillContext = fillContext;
	}

	/**
	 * Evaluates an expression.
	 * 
	 * @param expression the expression to evaluate
	 * @param evaluation the evaluation type
	 * @return the evaluation result
	 * @throws JRException
	 */
	protected final Object evaluateExpression(JRExpression expression, byte evaluation) throws JRException
	{
		return fillContext.evaluate(expression, evaluation);
	}

	/**
	 * The default implementation throws {@link UnsupportedOperationException}.
	 * 
	 * <p>
	 * If a component supports delayed evaluation, it needs to override this
	 * method.
	 */
	public void evaluateDelayedElement(JRPrintElement element, byte evaluation)
			throws JRException
	{
		throw new UnsupportedOperationException("");
	}

	/**
	 * The default implementation is empty.
	 * 
	 * <p>
	 * Override this method if something needs to be done on component rewind.
	 */
	public void rewind()
	{
		// NOOP
	}
	
}