org.jfree.report.function
Class TotalCalculationFunction

java.lang.Object
  org.jfree.report.function.AbstractFunction
      org.jfree.report.function.TotalCalculationFunction

All Implemented Interfaces:

java.lang.Cloneable, java.util.EventListener, Expression, Function, ReportListener, java.io.Serializable

public class TotalCalculationFunction

extends AbstractFunction

implements java.io.Serializable

A report function that stores the result of a calculation for a group or the complete report. The field value, that was read when the group finished, is stored and returned when the group gets active again in a higher processing level.

This function can be used to calculate total values for a group, f.I. a TotalMax for the group, which returns the maximum value encountered for that field in the current group. The computed values are available to all bands of the group.

The function undestands two parameters, the field parameter is required and denotes the name of an ItemBand-field which gets summed up.

The parameter group denotes the name of a group. When this group is started, the counter gets reseted to null. This parameter is optional.

Author:

Thomas Morgner

See Also:

Serialized Form

Field Summary

static java.lang.String	FIELD_PROPERTY Literal text for the 'field' property.
static java.lang.String	GROUP_PROPERTY Literal text for the 'group' property.

Fields inherited from interface org.jfree.report.function.Expression

AUTOACTIVATE_PROPERTY

Constructor Summary

TotalCalculationFunction()
Constructs a new function.

Method Summary

java.lang.String	getField() Returns the name of the group to be totalled.
java.lang.String	getGroup() Returns the name of the group to be totalled.
java.lang.Object	getValue() Return the current expression value.
void	groupFinished(ReportEvent event) Receives notification that a group has finished.
void	groupStarted(ReportEvent event) Receives notification that a group has started.
void	initialize() Checks that the function has been correctly initialized.
void	reportFinished(ReportEvent event) Receives notification that the report has finished.
void	reportInitialized(ReportEvent event) Receives notification that the report has started.
void	setField(java.lang.String field) Defines the name of the group to be totalled.
void	setGroup(java.lang.String group) Defines the name of the group to be totalled.

Methods inherited from class org.jfree.report.function.AbstractFunction

clone, getDataRow, getDependencyLevel, getInstance, getName, getProperties, getProperty, getProperty, isActive, itemsAdvanced, itemsFinished, itemsStarted, reportDone, reportStarted, setDataRow, setDependencyLevel, setName, setProperties, setProperty

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FIELD_PROPERTY

public static final java.lang.String FIELD_PROPERTY

Literal text for the 'field' property.

See Also:

Constant Field Values

GROUP_PROPERTY

public static final java.lang.String GROUP_PROPERTY

Literal text for the 'group' property.

See Also:

Constant Field Values

Constructor Detail

TotalCalculationFunction

public TotalCalculationFunction()

Constructs a new function.

Initially the function has no name...be sure to assign one before using the function.

Method Detail

reportInitialized

public void reportInitialized(ReportEvent event)

Receives notification that the report has started.

Specified by:

reportInitialized in interface ReportListener

Overrides:

reportInitialized in class AbstractFunction

Parameters:

event - the event.

groupStarted

public void groupStarted(ReportEvent event)

Receives notification that a group has started.

Specified by:

groupStarted in interface ReportListener

Overrides:

groupStarted in class AbstractFunction

Parameters:

event - the event.

groupFinished

public void groupFinished(ReportEvent event)

Receives notification that a group has finished.

Specified by:

groupFinished in interface ReportListener

Overrides:

groupFinished in class AbstractFunction

Parameters:

event - the event.

reportFinished

public void reportFinished(ReportEvent event)

Receives notification that the report has finished.

Specified by:

reportFinished in interface ReportListener

Overrides:

reportFinished in class AbstractFunction

Parameters:

event - the event.

getGroup

public java.lang.String getGroup()

Returns the name of the group to be totalled.

Returns:

the group name.

setGroup

public void setGroup(java.lang.String group)

Defines the name of the group to be totalled. If the name is null, all groups are totalled.

Parameters:

group - the group name.

getField

public java.lang.String getField()

Returns the name of the group to be totalled.

Returns:

the group name.

setField

public void setField(java.lang.String field)

Defines the name of the group to be totalled. If the name is null, all groups are totalled.

Parameters:

field - the field name.

getValue

public java.lang.Object getValue()

Return the current expression value.

The value depends (obviously) on the expression implementation.

Specified by:

getValue in interface Expression

Returns:

the value of the function.

initialize

public void initialize()
                throws FunctionInitializeException

Checks that the function has been correctly initialized.

The only check performed at present is to make sure the name is not null.

Specified by:

initialize in interface Expression

Overrides:

initialize in class AbstractFunction

Throws:

FunctionInitializeException - in case the function is not initialized properly.