Interface ObservableView<T extends @Nullable Object>

Type Parameters:

T - the contained value type

All Superinterfaces:

Supplier<T>

All Known Implementing Classes:

ObservableProperty

public interface ObservableView<T extends @Nullable Object>
extends Supplier<T>

A read-only observable property.

Since:

4.2.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	ObservableView.ChangeListener<T extends @Nullable Object>	A listener for changes in observable views and properties.

Method Summary

Modifier and Type	Method	Description
void	addListener(ObservableView.ChangeListener<? super T> listener)	Adds a change listener to this property view.
default Optional<T>	find()	Returns the nonnull value of this property, or Optional.empty() if null or not initialized.
T	get()	Returns the value of this property.
default @Nullable T	getOrNull()	Returns the value of this property, or null if not initialized.
boolean	hasValue()	Returns whether this property has been set to a value.
void	removeListener(ObservableView.ChangeListener<? super T> listener)	Removes a change listener from this property view if present.

Method Details

hasValue

boolean hasValue()

Returns whether this property has been set to a value.

Returns:

whether this property has been set to a value

get

T get()

Returns the value of this property.

Specified by:

get in interface Supplier<T extends @Nullable Object>

Returns:

the value of this property

Throws:

IllegalStateException - if not initialized

See Also:

• hasValue()

getOrNull

default @Nullable T getOrNull()

Returns the value of this property, or null if not initialized.

Returns:

the value of this property, or null if not initialized

find

default Optional<T> find()

Returns the nonnull value of this property, or Optional.empty() if null or not initialized.

Returns:

the nonnull value of this property, or Optional.empty() if null or not initialized

addListener

void addListener(ObservableView.ChangeListener<? super T> listener)

Adds a change listener to this property view.

Parameters:

listener - the added listener

removeListener

void removeListener(ObservableView.ChangeListener<? super T> listener)

Removes a change listener from this property view if present.

Parameters:

listener - the removed listener