/*
* 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.fill;
/**
* Interface for objects that can be used by extended incrementers for calculations.
*
* @author Lucian Chirita (lucianc@users.sourceforge.net)
* @version $Id: JRCalculable.java 3034 2009-08-27 11:58:04Z teodord $
* @see net.sf.jasperreports.engine.fill.JRExtendedIncrementer
*/
public interface JRCalculable
{
/**
* Constant for the count helper variable.
*/
static final byte HELPER_COUNT = 0;
/**
* Constant for the sum helper variable.
*/
static final byte HELPER_SUM = 1;
/**
* Constant for the variance helper variable.
*/
static final byte HELPER_VARIANCE = 2;
/**
* The number of defined helper variables.
*/
static final int HELPER_SIZE = 3;
/**
* Returns <code>true</code> if and only if the calculable object was only initialized and not incremented.
*
* @return <code>true</code> if and only if the calculable object was only initialized and not incremented
*/
boolean isInitialized();
/**
* Sets the initialized flag for this calculable object.
* @param isInitialized the initialized flag
* @see #isInitialized()
*/
void setInitialized(boolean isInitialized);
/**
* Returns the incremented value of the calculable object.
*
* @return the incremented value
*/
Object getIncrementedValue();
/**
* Returns the value of the calculable object.
*
* @return the value
*/
Object getValue();
/**
* Returns a helper variable.
*
* @param helperType the desired helper variable type
* @return the helper variable
*/
JRCalculable getHelperVariable(byte helperType);
}
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