org.jfree.chart
Class Legend

java.lang.Object
  org.jfree.chart.Legend

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

Direct Known Subclasses:

StandardLegend

public abstract class Legend

extends java.lang.Object

implements java.io.Serializable, java.lang.Cloneable

A chart legend shows the names and visual representations of the series that are plotted in a chart.

Author:

David Gilbert

See Also:

StandardLegend, Serialized Form

Field Summary

static int	EAST Constant anchor value for legend position EAST.
protected static int	HORIZONTAL Internal value indicating the bit holding the value of interest in the anchor value.
protected static int	INVERTED Internal value indicating the bit holding the value of interest in the anchor value.
static int	NORTH Constant anchor value for legend position NORTH.
static int	SOUTH Constant anchor value for legend position SOUTH.
static int	WEST Constant anchor value for legend position WEST.

Constructor Summary

	Legend() Default constructor.
protected	Legend(JFreeChart chart) Deprecated. use the default constructor instead and let JFreeChart manage the chart reference

Method Summary

void	addChangeListener(LegendChangeListener listener) Registers an object for notification of changes to the legend.
protected java.lang.Object	clone() Clones the legend, and takes care of listeners.
static Legend	createInstance(JFreeChart chart) Static factory method that returns a concrete subclass of Legend.
abstract java.awt.geom.Rectangle2D	draw(java.awt.Graphics2D g2, java.awt.geom.Rectangle2D available, ChartRenderingInfo info) Draws the legend on a Java 2D graphics device (such as the screen or a printer).
boolean	equals(java.lang.Object obj) Tests this legend for equality with another object.
int	getAnchor() Returns the current anchor of this legend.
JFreeChart	getChart() Returns the chart that this legend belongs to.
protected void	notifyListeners(LegendChangeEvent event) Notifies all registered listeners that the chart legend has changed in some way.
protected void	registerChart(JFreeChart chart) Internal maintenace method to update the reference to the central JFreeChart object.
void	removeChangeListener(LegendChangeListener listener) Deregisters an object for notification of changes to the legend.
void	setAnchor(int anchor) Sets the current anchor of this legend.

Methods inherited from class java.lang.Object

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

Field Detail

WEST

public static final int WEST

Constant anchor value for legend position WEST.

See Also:

Constant Field Values

NORTH

public static final int NORTH

Constant anchor value for legend position NORTH.

See Also:

Constant Field Values

EAST

public static final int EAST

Constant anchor value for legend position EAST.

See Also:

Constant Field Values

SOUTH

public static final int SOUTH

Constant anchor value for legend position SOUTH.

See Also:

Constant Field Values

INVERTED

protected static final int INVERTED

Internal value indicating the bit holding the value of interest in the anchor value.

See Also:

Constant Field Values

HORIZONTAL

protected static final int HORIZONTAL

Internal value indicating the bit holding the value of interest in the anchor value.

See Also:

Constant Field Values

Constructor Detail

Legend

public Legend()

Default constructor.

Legend

protected Legend(JFreeChart chart)

Deprecated. use the default constructor instead and let JFreeChart manage the chart reference

Creates a new legend.

Parameters:

chart - the chart that the legend belongs to.

Method Detail

createInstance

public static Legend createInstance(JFreeChart chart)

Static factory method that returns a concrete subclass of Legend.

Parameters:

chart - the chart that the legend belongs to.

Returns:

a StandardLegend.

getChart

public JFreeChart getChart()

Returns the chart that this legend belongs to.

Returns:

the chart.

registerChart

protected void registerChart(JFreeChart chart)

Internal maintenace method to update the reference to the central JFreeChart object.

Parameters:

chart - the chart, may be null, if the legend gets removed from the chart.

draw

public abstract java.awt.geom.Rectangle2D draw(java.awt.Graphics2D g2,
                                               java.awt.geom.Rectangle2D available,
                                               ChartRenderingInfo info)

Draws the legend on a Java 2D graphics device (such as the screen or a printer).

Parameters:

g2 - the graphics device.

available - the area within which the legend (and plot) should be drawn.

info - a carrier for returning information about the entities in the legend.

Returns:

the area remaining after the legend has drawn itself.

addChangeListener

public void addChangeListener(LegendChangeListener listener)

Registers an object for notification of changes to the legend.

Parameters:

listener - the object that is being registered.

removeChangeListener

public void removeChangeListener(LegendChangeListener listener)

Deregisters an object for notification of changes to the legend.

Parameters:

listener - the object that is being deregistered.

notifyListeners

protected void notifyListeners(LegendChangeEvent event)

Notifies all registered listeners that the chart legend has changed in some way.

Parameters:

event - information about the change to the legend.

getAnchor

public int getAnchor()

Returns the current anchor of this legend.

The default anchor for this legend is SOUTH.

Returns:

the current anchor.

setAnchor

public void setAnchor(int anchor)

Sets the current anchor of this legend.

The anchor can be one of: NORTH, SOUTH, EAST, WEST. If a valid anchor value is provided, the current anchor is set and an update event is triggered. Otherwise, no change is made.

Parameters:

anchor - the new anchor value.

equals

public boolean equals(java.lang.Object obj)

Tests this legend for equality with another object.

Parameters:

obj - the object.

Returns:

true or false.

clone

protected java.lang.Object clone()
                          throws java.lang.CloneNotSupportedException

Clones the legend, and takes care of listeners. Note: the cloned legend refer to the same chart as the original one. JFreeChart clone() takes care of setting the references correctly.

Returns:

A clone.

Throws:

java.lang.CloneNotSupportedException - if the object cannot be cloned.