Observable

Kotlin |Java

public abstract class Observable
extends Object

java.lang.Object
↳	android.database.Observable<T>

Known direct subclasses

ContentObservable, DataSetObservable

ContentObservable	A specialization of `Observable` for `ContentObserver` that provides methods for sending notifications to a list of `ContentObserver` objects.
DataSetObservable	A specialization of `Observable` for `DataSetObserver` that provides methods for sending notifications to a list of `DataSetObserver` objects.

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

Added in API level 1

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

Added in API level 1

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

Added in API level 1

public void unregisterAll ()

Remove all registered observers.

unregisterObserver

Added in API level 1

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