/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 Lesser General Public License for more details.
*
* Copyright (c) 2009 Pentaho Corporation.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.function.formula;
import java.math.BigDecimal;
import org.pentaho.reporting.engine.classic.core.function.ReportFormulaContext;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.FormulaContext;
import org.pentaho.reporting.libraries.formula.LibFormulaErrorValue;
import org.pentaho.reporting.libraries.formula.function.Function;
import org.pentaho.reporting.libraries.formula.function.ParameterCallback;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
/**
* Todo: Document Me
*
* @author Thomas Morgner
*/
public class RowCountFunction implements Function
{
public RowCountFunction()
{
}
public String getCanonicalName()
{
return "ROWCOUNT";
}
public TypeValuePair evaluate(final FormulaContext context,
final ParameterCallback parameters) throws EvaluationException
{
final int parameterCount = parameters.getParameterCount();
if (parameterCount > 1)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
final ReportFormulaContext rfc = (ReportFormulaContext) context;
final int groupStart;
if (parameterCount == 0)
{
groupStart = rfc.getRuntime().getGroupStartRow(-1);
}
else
{
final String groupName = context.getTypeRegistry().convertToText(parameters.getType(0), parameters.getValue(0));
groupStart = rfc.getRuntime().getGroupStartRow(groupName);
}
final int row = rfc.getRuntime().getCurrentRow();
//noinspection UnpredictableBigDecimalConstructorCall
return new TypeValuePair(NumberType.GENERIC_NUMBER, new BigDecimal((double) (row - groupStart)));
}
}