org.jfree.report.function
Class ItemMinFunction

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

All Implemented Interfaces:

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

public class ItemMinFunction

extends AbstractFunction

implements java.io.Serializable

A report function that calculates the minimum value of one field (column) from the TableModel. The function can be used in two ways:

• to calculate a minimum value for the entire report;
• to calculate a minimum value 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.

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

ItemMinFunction()
Constructs an unnamed function.

ItemMinFunction(java.lang.String name)
Constructs a named function.

Method Summary

java.lang.String	getField() Returns the field used by the function.
java.lang.String	getGroup() Returns the group name.
Expression	getInstance() Return a completly separated copy of this function.
java.lang.Object	getValue() Returns the function value, in this case the running total of a specific column in the report's TableModel.
void	groupStarted(ReportEvent event) Receives notification that a new group is about to start.
void	initialize() Initializes the function and tests that all required properties are set.
void	itemsAdvanced(ReportEvent event) Receives notification that a row of data is being processed.
void	reportInitialized(ReportEvent event) Receives notification that a new report is about to start.
void	setField(java.lang.String field) Sets the field name for the function.
void	setGroup(java.lang.String name) Sets the group name.

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

ItemMinFunction

public ItemMinFunction()

Constructs an unnamed function. Make sure to set a Name or function initialisation will fail.

ItemMinFunction

public ItemMinFunction(java.lang.String name)

Constructs a named function.

The field must be defined before using the function.

Parameters:

name - The function name.

Method Detail

reportInitialized

public void reportInitialized(ReportEvent event)

Receives notification that a new report is about to start.

Does nothing.

Specified by:

reportInitialized in interface ReportListener

Overrides:

reportInitialized in class AbstractFunction

Parameters:

event - Information about the event.

groupStarted

public void groupStarted(ReportEvent event)

Receives notification that a new group is about to start. If this is the group defined for the function, then the minimum value is reset to zero.

Specified by:

groupStarted in interface ReportListener

Overrides:

groupStarted in class AbstractFunction

Parameters:

event - Information about the event.

getGroup

public java.lang.String getGroup()

Returns the group name.

Returns:

The group name.

setGroup

public void setGroup(java.lang.String name)

Sets the group name.

If a group is defined, the minimum value is reset to zero at the start of every instance of this group.

Parameters:

name - the group name (null permitted).

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).

itemsAdvanced

public void itemsAdvanced(ReportEvent event)

Receives notification that a row of data is being processed. Reads the data from the field defined for this function and calculates the minimum value.

Specified by:

itemsAdvanced in interface ReportListener

Overrides:

itemsAdvanced in class AbstractFunction

Parameters:

event - Information about the event.

getValue

public java.lang.Object getValue()

Returns the function value, in this case the running total of a specific column in the report's TableModel.

Specified by:

getValue in interface Expression

Returns:

The function value.

initialize

public void initialize()
                throws FunctionInitializeException

Initializes the function and tests that all required properties are set. If the required field property is not set, a FunctionInitializeException is thrown.

Specified by:

initialize in interface Expression

Overrides:

initialize in class AbstractFunction

Throws:

FunctionInitializeException - when no field is set.

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.