org.teavm.classlib.java.util

Class TObservable

java.lang.Object

org.teavm.classlib.java.util.TObservable

public class TObservable
extends Object

Author:

shannah

Constructor Summary

Constructors

Constructor and Description
TObservable() Constructs a new Observable object.

Method Summary

Modifier and Type	Method and Description
void	addObserver(TObserver observer) Adds the specified observer to the list of observers.
protected void	clearChanged() Clears the changed flag for this Observable.
int	countObservers() Returns the number of observers registered to this Observable.
void	deleteObserver(TObserver observer) Removes the specified observer from the list of observers.
void	deleteObservers() Removes all observers from the list of observers.
boolean	hasChanged() Returns the changed flag for this Observable.
void	notifyObservers() If hasChanged() returns true, calls the update() method for every observer in the list of observers using null as the argument.
void	notifyObservers(Object data) If hasChanged() returns true, calls the update() method for every Observer in the list of observers using the specified argument.
protected void	setChanged() Sets the changed flag for this Observable.

Methods inherited from class java.lang.Object

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

Constructor Detail

TObservable

public TObservable()

Constructs a new Observable object.

Method Detail

addObserver

public void addObserver(TObserver observer)

Adds the specified observer to the list of observers. If it is already registered, it is not added a second time.

Parameters:

observer - the Observer to add.

clearChanged

protected void clearChanged()

Clears the changed flag for this Observable. After calling clearChanged(), hasChanged() will return false.

countObservers

public int countObservers()

Returns the number of observers registered to this Observable.

Returns:

the number of observers.

deleteObserver

public void deleteObserver(TObserver observer)

Removes the specified observer from the list of observers. Passing null won't do anything.

Parameters:

observer - the observer to remove.

deleteObservers

public void deleteObservers()

Removes all observers from the list of observers.

hasChanged

public boolean hasChanged()

Returns the changed flag for this Observable.

Returns:

true when the changed flag for this Observable is set, false otherwise.

notifyObservers

public void notifyObservers()

If hasChanged() returns true, calls the update() method for every observer in the list of observers using null as the argument. Afterwards, calls clearChanged().

Equivalent to calling notifyObservers(null).

notifyObservers

public void notifyObservers(Object data)

If hasChanged() returns true, calls the update() method for every Observer in the list of observers using the specified argument. Afterwards calls clearChanged().

Parameters:

data - the argument passed to update().

setChanged

protected void setChanged()

Sets the changed flag for this Observable. After calling setChanged(), hasChanged() will return true.