Module javafx.base
Package javafx.collections

# Class WeakSetChangeListener<E>

java.lang.Object
javafx.collections.WeakSetChangeListener<E>

Type Parameters:
  `E` - The type of the observed value

All Implemented Interfaces:
  `WeakListener`, `SetChangeListener<E>`

    public final class WeakSetChangeListener<E>
    extends Object
    implements SetChangeListener<E>, WeakListener

A `WeakSetChangeListener` can be used, if an `ObservableSet` should only maintain a weak reference to the listener. This helps to avoid memory leaks, that can occur if observers are not unregistered from observed objects after use.

`WeakSetChangeListener` are created by passing in the original `SetChangeListener`. The `WeakSetChangeListener` should then be registered to listen for changes of the observed object.

Note: You have to keep a reference to the `SetChangeListener`, that was passed in as long as it is in use, otherwise it will be garbage collected to soon.

Since:
  JavaFX 2.1
See Also:
  `SetChangeListener`, `ObservableSet`, `WeakListener`

- ## Nested Class Summary

  ## Nested classes/interfaces declared in interface javafx.collections.SetChangeListener

  `SetChangeListener.Change<E>`

- ## Constructor Summary

  Constructors
  Constructor | Description
  --- | ---
  `WeakSetChangeListener​(SetChangeListener<E> listener)` | The constructor of `WeakSetChangeListener`.

- ## Method Summary

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

  ### Methods declared in interface javafx.collections.SetChangeListener

  `onChanged`

  ### Methods declared in interface javafx.beans.WeakListener

  `wasGarbageCollected`

- ## Constructor Details

  - ### WeakSetChangeListener

    public WeakSetChangeListener​(SetChangeListener<E> listener)
    The constructor of `WeakSetChangeListener`.
    Parameters:
      `listener` - The original listener that should be notified