Package org.eclipse.core.databinding.observable.value

Class WritableValue<T>

java.lang.Object

org.eclipse.core.databinding.observable.AbstractObservable

org.eclipse.core.databinding.observable.value.AbstractObservableValue<T>

org.eclipse.core.databinding.observable.value.WritableValue<T>

Type Parameters:

T - the type of value being observed

All Implemented Interfaces:

IObservable, IObservableValue<T>

public class WritableValue<T>
extends AbstractObservableValue<T>

Mutable (writable) implementation of IObservableValue that will maintain a value and fire change events when the value changes.

This class is thread safe. All state accessing methods must be invoked from the current realm. Methods for adding and removing listeners may be invoked from any thread.

Since:

1.0

Constructor Summary

Constructors

Constructor	Description
WritableValue()	Constructs a new instance with the default realm, a null value type, and a null value.
WritableValue(Realm realm)	Constructs a new instance with the provided realm, a null value type, and a null initial value.
WritableValue(Realm realm, T initialValue, Object valueType)	Constructs a new instance.
WritableValue(T initialValue, Object valueType)	Constructs a new instance with the default realm.

Method Summary

Modifier and Type	Method	Description
protected void	addListener(Object listenerType, IObservablesListener listener)
protected Object	clone()
T	doGetValue()
void	doSetValue(T value)	Template method for setting the value of the observable.
protected void	fireEvent(ObservableEvent event)
protected void	firstListenerAdded()
Realm	getRealm()
Object	getValueType()	The value type of this observable value, or null if this observable value is untyped.
protected boolean	hasListeners()
protected void	lastListenerRemoved()
protected void	removeListener(Object listenerType, IObservablesListener listener)
static <T2> WritableValue<T2>	withValueType(Object elementType)

Methods inherited from class org.eclipse.core.databinding.observable.value.AbstractObservableValue

addValueChangeListener, fireChange, fireValueChange, getValue, isStale, removeValueChangeListener, setValue

Methods inherited from class org.eclipse.core.databinding.observable.AbstractObservable

addChangeListener, addDisposeListener, addStaleListener, checkRealm, dispose, fireStale, isDisposed, removeChangeListener, removeDisposeListener, removeStaleListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.core.databinding.observable.IObservable

addChangeListener, addDisposeListener, addStaleListener, dispose, getRealm, isDisposed, removeChangeListener, removeDisposeListener, removeStaleListener

Constructor Detail

WritableValue

public WritableValue()

Constructs a new instance with the default realm, a null value type, and a null value.

WritableValue

public WritableValue(T initialValue,
                     Object valueType)

Constructs a new instance with the default realm.

Parameters:

initialValue - can be null

valueType - can be null

WritableValue

public WritableValue(Realm realm)

Constructs a new instance with the provided realm, a null value type, and a null initial value.

Parameters:

realm - the realm

WritableValue

public WritableValue(Realm realm,
                     T initialValue,
                     Object valueType)

Constructs a new instance.

Parameters:

realm - the realm

initialValue - can be null

valueType - can be null

Method Detail

doGetValue

public T doGetValue()

Specified by:

doGetValue in class AbstractObservableValue<T>

doSetValue

public void doSetValue(T value)

Description copied from class: AbstractObservableValue

Template method for setting the value of the observable. By default the method throws an UnsupportedOperationException.

Overrides:

doSetValue in class AbstractObservableValue<T>

Parameters:

value - The value to set.

getValueType

public Object getValueType()

Description copied from interface: IObservableValue

The value type of this observable value, or null if this observable value is untyped.

Returns:

the value type, or null

withValueType

public static <T2> WritableValue<T2> withValueType(Object elementType)

Type Parameters:

T2 - the type of observed value of the created instance

Parameters:

elementType - can be null

Returns:

new instance with the default realm and a value of null

addListener

protected void addListener(Object listenerType,
                           IObservablesListener listener)

Parameters:

listenerType - arbitrary object to identify a type of the listener

listener - the listener to add; not null

removeListener

protected void removeListener(Object listenerType,
                              IObservablesListener listener)

Parameters:

listenerType - arbitrary object to identify a type of the listener

listener - the listener to remove; not null

hasListeners

protected boolean hasListeners()

fireEvent

protected void fireEvent(ObservableEvent event)

firstListenerAdded

protected void firstListenerAdded()

lastListenerRemoved

protected void lastListenerRemoved()

getRealm

public Realm getRealm()

Returns:

Returns the realm.

clone

protected Object clone()
                throws CloneNotSupportedException

Overrides:

clone in class Object

Throws:

CloneNotSupportedException