Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> eclipse >> core >> internal >> [ runtime overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

org.eclipse.core.internal.runtime
Class ListenerList  

java.lang.Object
  org.eclipse.core.internal.runtime.ListenerList

---

public class ListenerList

extends java.lang.Object

Internal class to maintain a list of listeners. This class is a thread safe list that is optimized for frequent reads and infrequent writes. Copy on write is used to ensure readers can access the list without synchronization overhead. Readers are given access to the underlying array data structure for reading, with the trust that they will not modify the underlying array.

N.B.: This class is similar to other ListenerLists available throughout Eclipse code base, except that it uses equality instead of identity to compare listeners. This does not compromise efficiency (since listeners addition/removal is not a frequent operation) and provides more flexibility to clients.

Since:

3.0

---

Field Summary
private static java.lang.Object[]	EmptyArray           The empty array singleton instance.
private  java.lang.Object[]	listeners           The list of listeners.

 

Constructor Summary

ListenerList()           Creates a listener list.

 

Method Summary
void	add(java.lang.Object listener)           Adds the given listener to this list.
java.lang.Object[]	getListeners()           Returns an array containing all the registered listeners.
boolean	isEmpty()           Returns whether this listener list is empty.
void	remove(java.lang.Object listener)           Removes the given listener from this list.
int	size()           Returns the number of registered listeners.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

EmptyArray

private static final java.lang.Object[] EmptyArray

The empty array singleton instance.

---

listeners

private volatile java.lang.Object[] listeners

The list of listeners. Initially null but initialized to an array of size capacity the first time a listener is added. Maintains invariant: listeners != null

Constructor Detail

ListenerList

public ListenerList()

Creates a listener list.

Method Detail

add

public void add(java.lang.Object listener)

Adds the given listener to this list. Has no effect if an equal listener is already registered.

This method is synchronized to protect against multiple threads adding or removing listeners concurrently. This does not block concurrent readers.

---

getListeners

public java.lang.Object[] getListeners()

Returns an array containing all the registered listeners. The resulting array is unaffected by subsequent adds or removes. If there are no listeners registered, the result is an empty array singleton instance (no garbage is created). Use this method when notifying listeners, so that any modifications to the listener list during the notification will have no effect on the notification itself.

Note: callers must not modify the returned array.

---

isEmpty

public boolean isEmpty()

Returns whether this listener list is empty.

---

remove

public void remove(java.lang.Object listener)

Removes the given listener from this list. Has no effect if an identical listener was not already registered.

This method is synchronized to protect against multiple threads adding or removing listeners concurrently. This does not block concurrent readers.

---

size

public int size()

Returns the number of registered listeners.

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> eclipse >> core >> internal >> [ runtime overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---