/*
* 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 - 2016 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 org.pentaho.reporting.engine.classic.core.states.ReportStateKey;
import org.pentaho.reporting.engine.classic.core.util.Sequence;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.math.BigDecimal;
/**
* A report function that calculates the sum of one field (column) from the 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 sum for the entire report;</li> <li>to calculate a sum
* 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 understands two parameters, the <code>field</code> parameter is required and denotes the name of an
* ItemBand-field which gets summed up.
* <p/>
* The parameter <code>group</code> denotes the name of a group. When this group is started, the counter gets reset to
* null. This parameter is optional.
*
* @author Thomas Morgner
*/
public class TotalGroupSumFunction extends AbstractFunction implements FieldAggregationFunction {
/**
* A useful constant representing zero.
*/
protected static final BigDecimal ZERO = new BigDecimal( 0.0 );
private static final int ZERO_I = 0;
private StateSequence<BigDecimal> stateSequence;
private transient int lastGroupSequenceNumber;
/**
* The field that should be evaluated.
*/
private String field;
/**
* The name of the group on which to reset.
*/
private String group;
/**
* The currently computed result.
*/
private transient Sequence<BigDecimal> result;
/**
* The global state key is used to store the result for the whole report.
*/
private transient ReportStateKey globalStateKey;
/**
* The current group key is used to store the result for the current group.
*/
protected transient ReportStateKey currentGroupKey;
private String crosstabFilterGroup;
/**
* Constructs a new function.
* <p>
* Initially the function has no name...be sure to assign one before using the function.
*/
public TotalGroupSumFunction() {
stateSequence = new StateSequence<>();
}
/**
* Receives notification that the report has started.
*
* @param event the event.
*/
public void reportInitialized( final ReportEvent event ) {
globalStateKey = event.getState().getProcessKey();
if ( isPrepareRunLevel( event ) ) {
result = new Sequence<>();
stateSequence.clear();
stateSequence.add( globalStateKey, result );
lastGroupSequenceNumber = ZERO_I;
} else {
if ( stateSequence.resultExists() ) {
result = stateSequence.getResult( ZERO_I );
} else {
result = null;
}
lastGroupSequenceNumber = ZERO_I;
}
}
protected boolean isPrepareRunLevel( final ReportEvent event ) {
return FunctionUtilities.isDefinedPrepareRunLevel( this, event );
}
/**
* Receives notification that a group has started.
*
* @param event the event.
*/
public void groupStarted( final ReportEvent event ) {
if ( FunctionUtilities.isDefinedGroup( getGroup(), event ) ) {
currentGroupKey = event.getState().getProcessKey();
if ( isPrepareRunLevel( event ) ) {
clear();
int pos = this.stateSequence.getKeyIndex( currentGroupKey );
if ( pos == -1 ) {
this.stateSequence.add( currentGroupKey, result );
} else {
stateSequence.updateResult( pos, result );
}
} else {
// Activate the current group, which was filled in the prepare run.
int found = this.stateSequence.getKeyIndex( currentGroupKey );
if ( found < ZERO_I ) {
result = null;
} else {
result = stateSequence.getResult( found );
}
}
}
if ( FunctionUtilities.isDefinedGroup( getCrosstabFilterGroup(), event ) ) {
final int groupIndex = event.getState().getCurrentGroupIndex();
this.lastGroupSequenceNumber = (int) event.getState().getCrosstabColumnSequenceCounter( groupIndex );
}
}
protected void clear() {
result = new Sequence<>();
lastGroupSequenceNumber = ZERO_I;
}
/**
* Receives notification that a row of data is being processed.
*
* @param event the event.
*/
public void itemsAdvanced( final ReportEvent event ) {
if ( field == null ) {
return;
}
if ( isPrepareRunLevel( event ) == false ) {
return;
}
final BigDecimal value = ExpressionUtilities.convertToBigDecimal( event.getDataRow().get( getField() ) );
if ( value == null ) {
return;
}
final BigDecimal oldValue = result.get( lastGroupSequenceNumber );
if ( oldValue == null ) {
result.set( lastGroupSequenceNumber, value );
} else {
result.set( lastGroupSequenceNumber, oldValue.add( value ) );
}
}
public Object clone() throws CloneNotSupportedException {
final TotalGroupSumFunction o = (TotalGroupSumFunction) super.clone();
o.stateSequence = new StateSequence<>( stateSequence.getKeys().size() );
if ( result != null ) {
o.result = result.clone();
}
for ( int i = 0; i < stateSequence.getKeys().size(); i++ ) {
final ReportStateKey reportStateKey = stateSequence.getKeys().get( i );
if ( reportStateKey.equals( globalStateKey ) || reportStateKey.equals( currentGroupKey ) ) {
o.stateSequence.add( reportStateKey, o.result );
} else {
o.stateSequence.add( reportStateKey, stateSequence.getResult( i ) );
}
}
return o;
}
public void summaryRowSelection( final ReportEvent event ) {
if ( FunctionUtilities.isDefinedGroup( getCrosstabFilterGroup(), event ) ) {
final int groupIndex = event.getState().getCurrentGroupIndex();
this.lastGroupSequenceNumber = (int) event.getState().getCrosstabColumnSequenceCounter( groupIndex );
}
}
/**
* Returns the name of the group to be totalled.
*
* @return the group name.
*/
public String getGroup() {
return group;
}
/**
* 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.group = 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() {
if ( result == null ) {
return ZERO;
}
final BigDecimal value = result.get( lastGroupSequenceNumber );
if ( value == null ) {
return ZERO;
}
return value;
}
/**
* 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;
}
/**
* 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 TotalGroupSumFunction function = (TotalGroupSumFunction) super.getInstance();
function.result = null;
function.stateSequence = new StateSequence<>();
return function;
}
/**
* Helper function for the serialization.
*
* @param in the input stream.
* @throws IOException if an IO error occured.
* @throws ClassNotFoundException if a required class could not be found.
*/
private void readObject( final ObjectInputStream in ) throws IOException, ClassNotFoundException {
in.defaultReadObject();
this.result = null;
this.stateSequence = new StateSequence<>();
}
public String getCrosstabFilterGroup() {
return crosstabFilterGroup;
}
public void setCrosstabFilterGroup( final String crosstabFilterGroup ) {
this.crosstabFilterGroup = crosstabFilterGroup;
}
}