/*
* 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 - 2009 Object Refinery Ltd, Pentaho Corporation and Contributors.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.function;
import java.math.BigDecimal;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.engine.classic.core.event.ReportEvent;
/**
* Calculates the percentage value of a numeric field. The total sum is taken and divided by the number of items
* counted.
*
* @author Thomas Morgner
*/
public class ItemPercentageFunction extends AbstractFunction
{
private static final Log logger = LogFactory.getLog(ItemPercentageFunction.class);
/**
* A constant for the value 100.
*/
private static final BigDecimal HUNDRED = new BigDecimal(100);
/**
* A total group sum function.
*/
private TotalGroupSumFunction totalSumFunction;
/**
* The current value.
*/
private transient BigDecimal currentValue;
/**
* A useful constant representing zero.
*/
private static final BigDecimal ZERO = new BigDecimal(0.0);
/**
* The name of the group on which to reset the count. This can be set to null to compute the percentage for the whole
* report.
*/
private String group;
/**
* The name of the field from where to read the values.
*/
private String field;
/**
* The scale-property defines the precission of the divide-operation.
*/
private int scale;
/**
* The rounding-property defines the precission of the divide-operation.
*/
private int roundingMode;
/**
* A flag defining whether the returned value should be scaled to 100.
*/
private boolean scaleToHundred;
/**
* Creates a new ItemPercentageFunction.
*/
public ItemPercentageFunction()
{
totalSumFunction = new TotalGroupSumFunction();
totalSumFunction.setName("total");
scale = 14;
roundingMode = BigDecimal.ROUND_HALF_UP;
scaleToHundred = true;
}
/**
* Returns whether the returned value should be scaled to 100.
*
* @return true, if the value should be scaled to 100, false otherwise.
*/
public boolean isScaleToHundred()
{
return scaleToHundred;
}
/**
* Defines whether the returned value should be scaled to 100.
*
* @param scaleToHundred true, if the value should be scaled to 100, false otherwise.
*/
public void setScaleToHundred(final boolean scaleToHundred)
{
this.scaleToHundred = scaleToHundred;
}
/**
* 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;
}
/**
* Returns the group name.
*
* @return The group name.
*/
public String getGroup()
{
return group;
}
/**
* Sets the group name. <P> If a group is defined, the minimum value is reset to zero at the start of every instance
* of this group.
*
* @param name the group name (null permitted).
*/
public void setGroup(final String name)
{
this.group = name;
this.totalSumFunction.setGroup(group);
}
/**
* Returns the field used by the function. The field name corresponds to a column name in the report's data-row.
*
* @return The field name.
*/
public String getField()
{
return field;
}
/**
* Sets the field name for the function. The field name corresponds to a column name in the report's data-row.
*
* @param field the field name.
*/
public void setField(final String field)
{
this.field = field;
this.totalSumFunction.setField(field);
}
/**
* Receives notification that the report has started.
*
* @param event the event.
*/
public void reportStarted(final ReportEvent event)
{
totalSumFunction.reportStarted(event);
final Object fieldValue = event.getDataRow().get(getField());
if (fieldValue == null)
{
// No add, field is null
currentValue = ItemPercentageFunction.ZERO;
return;
}
try
{
final Number n = (Number) fieldValue;
currentValue = new BigDecimal(n.toString());
}
catch (Exception e)
{
ItemPercentageFunction.logger.error("ItemPercentageFunction.reportStarted(): problem adding number.");
}
}
/**
* Receives notification that a group has started.
*
* @param event the event.
*/
public void groupStarted(final ReportEvent event)
{
totalSumFunction.groupStarted(event);
final Object fieldValue = event.getDataRow().get(getField());
if (fieldValue == null)
{
// No add, field is null
currentValue = ItemPercentageFunction.ZERO;
return;
}
try
{
final Number n = (Number) fieldValue;
currentValue = new BigDecimal(n.toString());
}
catch (Exception e)
{
ItemPercentageFunction.logger.error("ItemPercentageFunction.groupStarted(): problem adding number.");
}
}
/**
* Receives notification that a row of data is being processed.
*
* @param event the event.
*/
public void itemsAdvanced(final ReportEvent event)
{
totalSumFunction.itemsAdvanced(event);
final Object fieldValue = event.getDataRow().get(getField());
if (fieldValue == null)
{
// No add, field is null
currentValue = ItemPercentageFunction.ZERO;
return;
}
try
{
final Number n = (Number) fieldValue;
currentValue = new BigDecimal(n.toString());
}
catch (Exception e)
{
ItemPercentageFunction.logger.error("ItemPercentageFunction.advanceItems(): problem adding number.");
}
}
/**
* Receives notification that the report has started.
*
* @param event the event.
*/
public void reportInitialized(final ReportEvent event)
{
totalSumFunction.reportInitialized(event);
currentValue = ItemPercentageFunction.ZERO;
}
/**
* Return the current function value. <P> Don not count on the correctness of this function until the preparerun has
* finished.
*
* @return The value of the function.
*/
public Object getValue()
{
final BigDecimal total = (BigDecimal) totalSumFunction.getValue();
if (total == null || total.doubleValue() == 0)
{
return null;
}
if (scaleToHundred)
{
return currentValue.multiply(ItemPercentageFunction.HUNDRED).divide(total, scale, roundingMode);
}
else
{
return currentValue.divide(total, scale, roundingMode);
}
}
/**
* Returns a clone of the function. <P> Be aware, this does not create a deep copy. If you have complex strucures
* contained in objects, you have to overwrite this function.
*
* @return A clone of the function.
* @throws CloneNotSupportedException this should never happen.
*/
public Object clone()
throws CloneNotSupportedException
{
final ItemPercentageFunction clone = (ItemPercentageFunction) super.clone();
clone.totalSumFunction = (TotalGroupSumFunction) totalSumFunction.clone();
return clone;
}
/**
* Return a completly separated copy of this function. The copy does no longer share any changeable objects with the
* original function.
*
* @return a copy of this function.
*/
public Expression getInstance()
{
final ItemPercentageFunction function = (ItemPercentageFunction) super.getInstance();
function.totalSumFunction = (TotalGroupSumFunction) totalSumFunction.getInstance();
function.currentValue = ItemPercentageFunction.ZERO;
return function;
}
public void setDependencyLevel(final int level)
{
super.setDependencyLevel(level);
totalSumFunction.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.
* <p/>
* This updates the internal TotalItemSumFunction.
*
* @param runtime the runtime information for the expression
*/
public void setRuntime(final ExpressionRuntime runtime)
{
super.setRuntime(runtime);
totalSumFunction.setRuntime(runtime);
}
}