/*
* 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) 2001 - 2013 Object Refinery Ltd, Pentaho Corporation and Contributors.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.function;
import org.pentaho.reporting.engine.classic.core.event.ReportEvent;
import java.math.BigDecimal;
/**
* A report function that calculates the quotient of two summed fields (columns) from the report's data row. This
* function produces a global total. The total sum of the group is known when the group processing starts and the report
* is not performing a prepare-run. The sum is calculated in the prepare run and recalled in the printing run.
* <p/>
* The function can be used in two ways:
* <ul>
* <li>to calculate a quotient for the entire report;</li>
* <li>to calculate a quotient within a particular group;</li>
* </ul>
* This function expects its input values to be either java.lang.Number instances or Strings that can be parsed to
* java.lang.Number instances using a java.text.DecimalFormat.
* <p/>
* The function undestands tree parameters. The <code>dividend</code> parameter is required and denotes the name of an
* ItemBand-field which gets summed up as dividend. The <code>divisor</code> parameter is required and denotes the name
* of an ItemBand-field which gets summed up as divisor.
* <p/>
* The parameter <code>group</code> denotes the name of a group. When this group is started, the counter gets reseted to
* null. This parameter is optional.
*
* @author Thomas Morgner
*/
public class TotalGroupSumQuotientFunction extends AbstractFunction {
/**
* Internal function to compute the dividend.
*/
private TotalGroupSumFunction dividendFunction;
/**
* Internal function to compute the divisor.
*/
private TotalGroupSumFunction divisorFunction;
/**
* The scale-property defines the precession of the divide-operation.
*/
private int scale;
/**
* The rounding-property defines the precession of the divide-operation.
*/
private int roundingMode;
/**
* Constructs a new function.
* <p/>
* Initially the function has no name...be sure to assign one before using the function.
*/
public TotalGroupSumQuotientFunction() {
scale = 14;
roundingMode = BigDecimal.ROUND_HALF_UP;
dividendFunction = new TotalGroupSumFunction();
divisorFunction = new TotalGroupSumFunction();
}
/**
* Receives notification that the report has started.
*
* @param event
* the event.
*/
public void reportInitialized( final ReportEvent event ) {
dividendFunction.reportInitialized( event );
divisorFunction.reportInitialized( event );
}
/**
* Receives notification that a group has started.
*
* @param event
* the event.
*/
public void groupStarted( final ReportEvent event ) {
dividendFunction.groupStarted( event );
divisorFunction.groupStarted( event );
}
/**
* Receives notification that a row of data is being processed.
*
* @param event
* the event.
*/
public void itemsAdvanced( final ReportEvent event ) {
dividendFunction.itemsAdvanced( event );
divisorFunction.itemsAdvanced( event );
}
/**
* Returns the name of the group to be totalled.
*
* @return the group name.
*/
public String getGroup() {
return divisorFunction.getGroup();
}
/**
* Defines the name of the group to be totalled. If the name is null, all groups are totalled.
*
* @param group
* the group name.
*/
public void setGroup( final String group ) {
this.divisorFunction.setGroup( group );
this.dividendFunction.setGroup( group );
}
/**
* Return the current function value.
* <P>
* The value depends (obviously) on the function implementation. For example, a page counting function will return the
* current page number.
*
* @return The value of the function.
*/
public Object getValue() {
final BigDecimal dividend = (BigDecimal) dividendFunction.getValue();
final BigDecimal divisor = (BigDecimal) divisorFunction.getValue();
if ( divisor == null || dividend == null || divisor.doubleValue() == 0 ) {
return null;
}
return dividend.divide( divisor, scale, roundingMode );
}
/**
* Returns the field used as dividend by the function.
* <P>
* The field name corresponds to a column name in the report's data-row.
*
* @return The field name.
*/
public String getDividend() {
return this.dividendFunction.getField();
}
/**
* Returns the field used as divisor by the function.
* <P>
* The field name corresponds to a column name in the report's data row.
*
* @return The field name.
*/
public String getDivisor() {
return this.divisorFunction.getField();
}
/**
* Sets the field name to be used as dividend for the function.
* <P>
* The field name corresponds to a column name in the report's data-row.
*
* @param dividend
* the field name (null not permitted).
*/
public void setDividend( final String dividend ) {
this.dividendFunction.setField( dividend );
}
/**
* Sets the field name to be used as divisor for the function.
* <P>
* The field name corresponds to a column name in the report's data-row.
*
* @param divisor
* the field name (null not permitted).
*/
public void setDivisor( final String divisor ) {
this.divisorFunction.setField( divisor );
}
/**
* Returns the defined rounding mode. This influences the precision of the divide-operation.
*
* @return the rounding mode.
* @see java.math.BigDecimal#divide(java.math.BigDecimal, int)
*/
public int getRoundingMode() {
return roundingMode;
}
/**
* Defines the rounding mode. This influences the precision of the divide-operation.
*
* @param roundingMode
* the rounding mode.
* @see java.math.BigDecimal#divide(java.math.BigDecimal, int)
*/
public void setRoundingMode( final int roundingMode ) {
this.roundingMode = roundingMode;
}
/**
* Returns the scale for the divide-operation. The scale influences the precision of the division.
*
* @return the scale.
*/
public int getScale() {
return scale;
}
/**
* Defines the scale for the divide-operation. The scale influences the precision of the division.
*
* @param scale
* the scale.
*/
public void setScale( final int scale ) {
this.scale = scale;
}
/**
* Defines the function's dependency level. This method forwards all calls to the interal functions.
*
* @param level
* the dependency level.
* @see Expression#getDependencyLevel()
*/
public void setDependencyLevel( final int level ) {
super.setDependencyLevel( level );
dividendFunction.setDependencyLevel( level );
divisorFunction.setDependencyLevel( level );
}
/**
* Defines the ExpressionRune used in this expression. The ExpressionRuntime is set before the expression receives
* events or gets evaluated and is unset afterwards. Do not hold references on the runtime or you will create
* memory-leaks.
*
* @param runtime
* the runtime information for the expression
*/
public void setRuntime( final ExpressionRuntime runtime ) {
super.setRuntime( runtime );
dividendFunction.setRuntime( runtime );
divisorFunction.setRuntime( runtime );
}
public String getCrosstabFilterGroup() {
return dividendFunction.getCrosstabFilterGroup();
}
public void setCrosstabFilterGroup( final String crosstabFilterGroup ) {
divisorFunction.setCrosstabFilterGroup( crosstabFilterGroup );
dividendFunction.setCrosstabFilterGroup( crosstabFilterGroup );
}
public Object clone() throws CloneNotSupportedException {
final TotalGroupSumQuotientFunction fn = (TotalGroupSumQuotientFunction) super.clone();
fn.dividendFunction = (TotalGroupSumFunction) dividendFunction.clone();
fn.divisorFunction = (TotalGroupSumFunction) divisorFunction.clone();
return fn;
}
}