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public abstract class Observable
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.

Summary

Fields

protected final ArrayList<T> mObservers

The list of observers.

Public constructors

Observable()

Public methods

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.

Inherited methods

From class java.lang.Object

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Fields

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.

Public constructors

Observable

public Observable ()

Public methods

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 T: the observer to register
Throws
IllegalArgumentException the observer is null
IllegalStateException the observer is already registered

unregisterAll

public void unregisterAll ()

Remove all registered observers.

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 T: the observer to unregister
Throws
IllegalArgumentException the observer is null
IllegalStateException the observer is not yet registered

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Last updated 2023-02-08 UTC.