android.database

Class Observable<T>

java.lang.Object

android.database.Observable<T>

Direct Known Subclasses:

DataSetObservable

public abstract class Observable<T>
extends Object

Provides methods for registering or unregistering arbitrary observers in an ArrayList. This abstract class is intended to be subclassed and specialized to maintain a registry of observers of specific types and dispatch notifications to them.

Field Summary

Fields

Modifier and Type	Field and Description
protected ArrayList<T>	mObservers The list of observers.

Constructor Summary

Constructors

Constructor and Description
Observable()

Method Summary

Modifier and Type	Method and Description
void	registerObserver(T observer) Adds an observer to the list.
void	unregisterAll() Remove all registered observers.
void	unregisterObserver(T observer) Removes a previously registered observer.

Methods inherited from class java.lang.Object

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

Field Detail

mObservers

protected final ArrayList<T> mObservers

The list of observers. An observer can be in the list at most once and will never be null.

Constructor Detail

Observable

public Observable()

Method Detail

registerObserver

public void registerObserver(T observer)

Adds an observer to the list. The observer cannot be null and it must not already be registered.

Parameters:

observer - the observer to register

Throws:

IllegalArgumentException - the observer is null

IllegalStateException - the observer is already registered

unregisterObserver

public void unregisterObserver(T observer)

Removes a previously registered observer. The observer must not be null and it must already have been registered.

Parameters:

observer - the observer to unregister

Throws:

IllegalArgumentException - the observer is null

IllegalStateException - the observer is not yet registered

unregisterAll

public void unregisterAll()

Remove all registered observers.