info.monitorenter.gui.chart
Interface IAxisLabelFormatter

All Superinterfaces:

java.io.Serializable

All Known Implementing Classes:

ALabelFormatter, LabelFormatterAutoUnits, LabelFormatterDate, LabelFormatterNumber, LabelFormatterSimple, LabelFormatterUnit

public interface IAxisLabelFormatter
extends java.io.Serializable

An interface used by Axis to format labels and determine the maximum width for the labels.

In order to get as much labels as possible on the Chart2D's axes, an Axis should be configured in a way that reduces the return value of the method getMaxAmountChars().

Version:

$Revision: 1.5 $

Author:

Achim Westermann

See Also:

AAxis

Field Summary

static java.lang.String

PROPERTY_FORMATCHANGE Constant for PropertyChangeEvent fired when the configuration changes.

Method Summary

void	addPropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener listener) Registers a property change listener that will be informed about changes of the property identified by the given propertyName.
java.lang.String	format(double value) Provide a String for the value.
int	getMaxAmountChars() Returns the maximum amount of characters that will be returned from format(double).
double	getMinimumValueShiftForChange() Returns the minimum change in the value to format that will cause to return a different formatted String.
double	getNextEvenValue(double value, boolean ceiling) Returns the next "even" value to the given one.
AUnit	getUnit() Returns the unit that is currently used by this formatter.
void	initPaintIteration() Callback method invoked by the corresponding AAxis upon start of a paint iteration of the Chart2D.
java.lang.Number	parse(java.lang.String formatted) The reverse operation to format(double).
void	removePropertyChangeListener(java.lang.String property, java.beans.PropertyChangeListener listener) Deregisters a property change listener that has been registerd for listening on the given property.
void	setAxis(IAxis<?> axis) Allows the AAxis to register itself with the given formatter so that it may get information about the data (e.g.

Field Detail

PROPERTY_FORMATCHANGE

static final java.lang.String PROPERTY_FORMATCHANGE

Constant for PropertyChangeEvent fired when the configuration changes.

See Also:

Constant Field Values

Method Detail

addPropertyChangeListener

void addPropertyChangeListener(java.lang.String propertyName,
                               java.beans.PropertyChangeListener listener)

Registers a property change listener that will be informed about changes of the property identified by the given propertyName.

Parameters:

propertyName - the name of the property the listener is interested in

listener - a listener that will only be informed if the property identified by the argument propertyName changes

format

java.lang.String format(double value)

Provide a String for the value. Subclasses should override the label formatting here. The raw value is passed here to allow a general treatment. Transformations of this raw value should be done here (e.g. division by multiples of 1000 for scientific unit system display, date formatting,...).

Parameters:

value - the value to format.

Returns:

the formatted value.

getMaxAmountChars

int getMaxAmountChars()

Returns the maximum amount of characters that will be returned from format(double).

Returns:

the maximum amount of characters that will be returned from format(double).

getMinimumValueShiftForChange

double getMinimumValueShiftForChange()

Returns the minimum change in the value to format that will cause to return a different formatted String.

To achieve two different formatted Strings to be returned from the format method the corresponding values given to the format method have to differ at least by this value.

Some implementations (e.g. a formatter for date) have to use their own format method an increas a value to determine when the first change will occur. This is expensive and it's recommended that this action is performed once only and the result is stored. Additionally this routine has to start with an "even" (see getNextEvenValue(double, boolean)) value to get a correct result (the distance from even number to even number).

Returns:

the minimum change in the value to format that will cause to return a different formatted String.

getNextEvenValue

double getNextEvenValue(double value,
                        boolean ceiling)

Returns the next "even" value to the given one. "Even" means that the format method will exactly return the String for the value and not cut or round any information. A label String created with an "even" number will be exactly at the position it describes.

Parameters:

value - the value to get the next "even" value for.

ceiling - if true, the next higher number will returned, else the next lower one.

Returns:

the next "even" value to the given one.

getUnit

AUnit getUnit()

Returns the unit that is currently used by this formatter.

Returns:

the unit that is currently used by this formatter.

initPaintIteration

void initPaintIteration()

Callback method invoked by the corresponding AAxis upon start of a paint iteration of the Chart2D.

parse

java.lang.Number parse(java.lang.String formatted)
                       throws java.lang.NumberFormatException

The reverse operation to format(double).

The given argument has to be in the format that will be generated by that method or exceptions may be thrown.
test.parse(test.format(d))== d
has to be true if no rounding occurs by the formatter.

Parameters:

formatted - a String in the format that will be produced by method format(double).

Returns:

the parsed number.

Throws:

java.lang.NumberFormatException - if the format of the argument is invalid.

removePropertyChangeListener

void removePropertyChangeListener(java.lang.String property,
                                  java.beans.PropertyChangeListener listener)

Deregisters a property change listener that has been registerd for listening on the given property.

Parameters:

listener - a listener that will only be informed if the property identified by the argument propertyName changes

property - the property the listener was registered to.

setAxis

void setAxis(IAxis<?> axis)

Allows the AAxis to register itself with the given formatter so that it may get information about the data (e.g. range) it has to format.

This method should only be invoked by AAxis, all other invocations will cause trouble.

Parameters:

axis - the axis to gain information about.