AbstractOverlay

java.lang.Object
- org.jfree.chart.panel.AbstractOverlay

Direct Known Subclasses:

CrosshairOverlay
```
public class AbstractOverlay
extends java.lang.Object
```
A base class for implementing overlays for a ChartPanel.

Field Summary

Fields
Modifier and Type Field Description

private javax.swing.event.EventListenerList changeListeners
Storage for registered change listeners.

Constructor Summary

Constructors
Constructor Description

AbstractOverlay()
Default constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addChangeListener(OverlayChangeListener listener)`	Registers an object for notification of changes to the overlay.
`void`	`fireOverlayChanged()`	Sends a default `ChartChangeEvent` to all registered listeners.
`protected void`	`notifyListeners(OverlayChangeEvent event)`	Sends a `ChartChangeEvent` to all registered listeners.
`void`	`removeChangeListener(OverlayChangeListener listener)`	Deregisters an object for notification of changes to the overlay.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - changeListeners
```
private final transient javax.swing.event.EventListenerList changeListeners
```
    Storage for registered change listeners.
- Constructor Detail
  - AbstractOverlay
```
public AbstractOverlay()
```
    Default constructor.
- Method Detail
  - addChangeListener
```
public void addChangeListener(OverlayChangeListener listener)
```
    Registers an object for notification of changes to the overlay.
    
    Parameters:
    
    listener - the listener (null not permitted).
    
    See Also:
    
    removeChangeListener(OverlayChangeListener)
  - removeChangeListener
```
public void removeChangeListener(OverlayChangeListener listener)
```
    Deregisters an object for notification of changes to the overlay.
    
    Parameters:
    
    listener - the listener (null not permitted)
    
    See Also:
    
    addChangeListener(OverlayChangeListener)
  - fireOverlayChanged
```
public void fireOverlayChanged()
```
    Sends a default ChartChangeEvent to all registered listeners.
    This method is for convenience only.
  - notifyListeners
```
protected void notifyListeners(OverlayChangeEvent event)
```
    Sends a ChartChangeEvent to all registered listeners.
    
    Parameters:
    
    event - information about the event that triggered the notification.