Module is.codion.common.core

Package is.codion.common.value

Interface ValueObserver<T>

Type Parameters:

T - the type of the value

All Superinterfaces:

Observer<T>

All Known Subinterfaces:

ComponentValue<T,C>, EntityEditModel.EditableEntity.Exists, EntityEditModel.EditableEntity.Modified, EntityEditModel.EditableValue<T>, PropertyValue<T>, State, State.Combination, StateObserver, Value<T>, ValueList<T>, ValueListObserver<T>, Values<T,C>, ValueSet<T>, ValueSetObserver<T>, ValuesObserver<T,C>

All Known Implementing Classes:

AbstractComponentValue, AbstractTextComponentValue, AbstractValue

public interface ValueObserver<T>
extends Observer<T>

A read only value observer

Method Summary

Modifier and Type	Method	Description
T	get()
default boolean	isEqualTo(T value)	Returns true if the underlying value is equal to the given one.
default boolean	isNotEqualTo(T value)	Returns true if the underlying value is NOT equal to the given one.
default boolean	isNotNull()
default boolean	isNull()
boolean	nullable()	If false then get() is guaranteed to never return null.
default Optional<T>	optional()

Methods inherited from interface is.codion.common.observer.Observer

addConsumer, addListener, addWeakConsumer, addWeakListener, removeConsumer, removeListener, removeWeakConsumer, removeWeakListener

Method Details

get

T get()

Returns:

the value

optional

default Optional<T> optional()

Returns:

an Optional wrapping this value.

isNull

default boolean isNull()

Returns:

true if the underlying value is null.

isNotNull

default boolean isNotNull()

Returns:

true if the underlying value is not null.

nullable

boolean nullable()

If false then get() is guaranteed to never return null.

Returns:

true if this value can be null

isEqualTo

default boolean isEqualTo(T value)

Returns true if the underlying value is equal to the given one. Note that null == null.

Parameters:

value - the value

Returns:

true if the underlying value is equal to the given one

isNotEqualTo

default boolean isNotEqualTo(T value)

Returns true if the underlying value is NOT equal to the given one. Note that null == null.

Parameters:

value - the value

Returns:

true if the underlying value is NOT equal to the given one