Module javafx.base
Package javafx.beans.value

Interface ChangeListener<T>

All Known Implementing Classes:
WeakChangeListener
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface
public interface ChangeListener<T>
A ChangeListener is notified whenever the value of an ObservableValue changes. It can be registered and unregistered with ObservableValue.addListener(ChangeListener) respectively ObservableValue.removeListener(ChangeListener)

For an in-depth explanation of change events and how they differ from invalidation events, see the documentation of ObservableValue.

The same instance of ChangeListener can be registered to listen to multiple ObservableValues.

Since:
JavaFX 2.0
See Also:
ObservableValue

  • Method Summary

    Modifier and Type Method Description
    void changed​(ObservableValue<? extends T> observable, T oldValue, T newValue)
    Called when the value of an ObservableValue changes.

  • Method Details

    • changed

      void changed​(ObservableValue<? extends T> observable, T oldValue, T newValue)
      Called when the value of an ObservableValue changes.

      In general, it is considered bad practice to modify the observed value in this method.

      Parameters:
      observable - The ObservableValue which value changed
      oldValue - The old value
      newValue - The new value