org.jfree.report.function
Class TotalGroupSumFunction

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

All Implemented Interfaces:

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

public class TotalGroupSumFunction

extends AbstractFunction

implements java.io.Serializable

A report function that calculates the sum of one field (column) from the TableModel. 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.

The function can be used in two ways:

• to calculate a sum for the entire report;
• to calculate a sum within a particular group;

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.

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

TotalGroupSumFunction()
Constructs a new function.

Method Summary

java.lang.String	getField() Returns the field used by the function.
java.lang.String	getGroup() Returns the name of the group to be totalled.
Expression	getInstance() Return a completly separated copy of this function.
java.lang.Object	getValue() Return the current function value.
void	groupStarted(ReportEvent event) Receives notification that a group has started.
void	initialize() Checks that the function has been correctly initialized.
void	itemsAdvanced(ReportEvent event) Receives notification that a row of data is being processed.
void	reportInitialized(ReportEvent event) Receives notification that the report has started.
void	setField(java.lang.String field) Sets the field name for the function.
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, getName, getProperties, getProperty, getProperty, groupFinished, isActive, itemsFinished, itemsStarted, reportDone, reportFinished, 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

GROUP_PROPERTY

public static final java.lang.String GROUP_PROPERTY

Literal text for the 'group' property.

See Also:

Constant Field Values

FIELD_PROPERTY

public static final java.lang.String FIELD_PROPERTY

Literal text for the 'field' property.

See Also:

Constant Field Values

Constructor Detail

TotalGroupSumFunction

public TotalGroupSumFunction()

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.

itemsAdvanced

public void itemsAdvanced(ReportEvent event)

Receives notification that a row of data is being processed.

Specified by:

itemsAdvanced in interface ReportListener

Overrides:

itemsAdvanced 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.

getValue

public java.lang.Object getValue()

Return the current function value.

The value depends (obviously) on the function implementation. For example, a page counting function will return the current page number.

Specified by:

getValue in interface Expression

Returns:

The value of the function.

getField

public java.lang.String getField()

Returns the field used by the function.

The field name corresponds to a column name in the report's TableModel.

Returns:

The field name.

setField

public void setField(java.lang.String field)

Sets the field name for the function.

The field name corresponds to a column name in the report's TableModel.

Parameters:

field - the field name (null not permitted).

initialize

public void initialize()
                throws FunctionInitializeException

Checks that the function has been correctly initialized. If there is a problem, this method throws a FunctionInitializeException.

Specified by:

initialize in interface Expression

Overrides:

initialize in class AbstractFunction

Throws:

FunctionInitializeException - if the function name is not set or the call to isInitialized returns false.

getInstance

public Expression getInstance()

Return a completly separated copy of this function. The copy does no longer share any changeable objects with the original function.

Specified by:

getInstance in interface Expression

Overrides:

getInstance in class AbstractFunction

Returns:

a copy of this function.