Package sprouts

Interface ValDelegate<T>

Type Parameters:
T - The type of the value wrapped by the delegated property...
public interface ValDelegate<T>
A context object passed to the various types of change listeners registered on a property such as Val and Var. It exposes the state of the current property as well as the Channel constant from which the change originated.

  • Method Summary

    Modifier and Type
    Method
    Description
    SingleChange
    change()
    The type of change that occurred in the property.
    Channel
    channel()
    The Channel constant from which the change originated.
    Maybe<T>
    currentValue()
    Exposes the value of the property that was listened to in an Maybe wrapper.
    String
    id()
    Exposes the id of the property that was listened to.
    Maybe<T>
    oldValue()
    Exposes the old value of the property that was listened to in an Maybe wrapper.
    Class<T>
    type()
    Exposes the type of the property that was listened to.

  • Method Details

    • type

      Class<T> type()
      Exposes the type of the property that was listened to.
      Returns:
      The type of the property that was listened to.

    • currentValue

      Maybe<T> currentValue()
      Exposes the value of the property that was listened to in an Maybe wrapper. If the new value is null, then the Maybe will be empty.
      Returns:
      An Maybe containing the new value of the property, or an empty Maybe if the new value is null.

    • oldValue

      Maybe<T> oldValue()
      Exposes the old value of the property that was listened to in an Maybe wrapper. If the old value was null, then the Maybe will be empty.
      Returns:
      An Maybe containing the old value of the property, or an empty Maybe if the old value was null.

    • channel

      Channel channel()
      The Channel constant from which the change originated. A channel is typically one of the From enum constants which is used to selectively listen to changes from different sources. You may want to define your own channels for your specific use case. This information can then also be used in your Actions to perform different tasks based on the channel from which the change originated.
      Returns:
      The Channel constant from which the change originated, usually one of the From enum constants.

    • id

      String id()
      Exposes the id of the property that was listened to. This is useful when you want to identify the property that changed in a listener that listens to multiple properties.
      Returns:
      The id of the property that was listened to.

    • change

      SingleChange change()
      The type of change that occurred in the property. This information can be used to perform different actions that are specific to the type of change.
      Returns:
      The mutation type of the change which may be one of the following: