Package org.aksw.commons.collection.observable

Class ObservableValueFromObservableCollection<T,U>

java.lang.Object

org.aksw.commons.collection.observable.ObservableValueFromObservableCollection<T,U>

Type Parameters:

T -

All Implemented Interfaces:

SingleValuedAccessor<T>, ObservableValue<T>

public class ObservableValueFromObservableCollection<T,U>
extends Object
implements ObservableValue<T>

Getter/setter view over an observable collection. If that collection has a single item then get() method returns it. Otherwise, if there are no or multiple items then the method returns null.

Author:

raven

Field Summary

Fields

Modifier and Type	Field	Description
protected ObservableCollection<U>	delegate
protected Function<? super T,? extends U>	valueToItem
protected Function<? super Collection<? extends U>,? extends T>	xform

Constructor Summary

Constructors

Constructor	Description
ObservableValueFromObservableCollection(ObservableCollection<U> delegate, Function<? super Collection<? extends U>,? extends T> xform, Function<? super T,? extends U> valueToItem)

Method Summary

Modifier and Type	Method	Description
Registration	addPropertyChangeListener(PropertyChangeListener listener)
Runnable	addVetoableChangeListener(VetoableChangeListener listener)
static <T> ObservableValue<T>	decorate(ObservableCollection<T> delegate)
T	get()	Attempt to get the only element from the underlying collection.
static <T> T	getOnlyElementOrNull(Iterable<T> iterable)
void	set(T value)	First clear the underlying collection.
static <T, U> PropertyChangeListener	wrapListener(Object self, PropertyChangeListener listener, Function<? super Collection<? extends U>,? extends T> xform)	Wrap the listener so that the set-based property change event is converted to a single value based on

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.aksw.commons.collection.observable.ObservableValue

addValueChangeListener, addVetoableChangeListener, convert

Methods inherited from interface org.aksw.commons.accessors.SingleValuedAccessor

getOrDefault

Field Details

delegate

protected ObservableCollection<U> delegate

xform

protected Function<? super Collection<? extends U>,? extends T> xform

valueToItem

protected Function<? super T,? extends U> valueToItem

Constructor Details

ObservableValueFromObservableCollection

public ObservableValueFromObservableCollection(ObservableCollection<U> delegate,
 Function<? super Collection<? extends U>,? extends T> xform,
 Function<? super T,? extends U> valueToItem)

Method Details

getOnlyElementOrNull

public static <T> T getOnlyElementOrNull(Iterable<T> iterable)

get

public T get()

Attempt to get the only element from the underlying collection. If that collection is empty or contains multiple (possible equal) elements then return null.

Specified by:

get in interface SingleValuedAccessor<T>

set

public void set(T value)

First clear the underlying collection. If the given value is non-null then add it to the collection.

Specified by:

set in interface SingleValuedAccessor<T>

wrapListener

public static <T,
U> PropertyChangeListener wrapListener(Object self,
 PropertyChangeListener listener,
 Function<? super Collection<? extends U>,? extends T> xform)

Wrap the listener so that the set-based property change event is converted to a single value based on

addPropertyChangeListener

public Registration addPropertyChangeListener(PropertyChangeListener listener)

Specified by:

addPropertyChangeListener in interface ObservableValue<T>

addVetoableChangeListener

public Runnable addVetoableChangeListener(VetoableChangeListener listener)

Specified by:

addVetoableChangeListener in interface ObservableValue<T>

decorate

public static <T> ObservableValue<T> decorate(ObservableCollection<T> delegate)