StateObserver

All Superinterfaces:: Observer<Boolean>, ValueObserver<Boolean>

All Known Subinterfaces:: EntityEditModel.EditableEntity.Exists, EntityEditModel.EditableEntity.Modified, State, State.Combination

public interface StateObserver extends ValueObserver<Boolean>

Specifies an observer for a State instance.

Method Summary

Modifier and Type

Method

Description

default boolean

isNotNull()

default boolean

isNull()

StateObserver

not()

default boolean

nullable()

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

Methods inherited from interface is.codion.common.observer.Observer
addConsumer, addListener, addWeakConsumer, addWeakListener, removeConsumer, removeListener, removeWeakConsumer, removeWeakListener

Methods inherited from interface is.codion.common.value.ValueObserver
get, isEqualTo, isNotEqualTo, optional

Method Details
- isNull
  
  default boolean isNull()
  
  Specified by:
  
  isNull in interface ValueObserver<Boolean>
  
  Returns:
  
  false
- isNotNull
  
  default boolean isNotNull()
  
  Specified by:
  
  isNotNull in interface ValueObserver<Boolean>
  
  Returns:
  
  true
- nullable
  
  default boolean nullable()
  
  Description copied from interface: ValueObserver
  
  If false then get() is guaranteed to never return null.
  
  Specified by:
  
  nullable in interface ValueObserver<Boolean>
  
  Returns:
  
  false
- not
  
  StateObserver not()
  
  Returns:
  
  A StateObserver instance that is always the reverse of this StateObserver instance