Module javafx.base
Package javafx.collections

Class MapChangeListener.Change<K,​V>

java.lang.Object
javafx.collections.MapChangeListener.Change<K,​V>
Type Parameters:
K - key type
V - value type
Enclosing interface:
MapChangeListener<K,​V>
public abstract static class MapChangeListener.Change<K,​V>
extends Object
An elementary change done to an ObservableMap. Change contains information about a put or remove operation. Note that put operation might remove an element if there was already a value associated with the same key. In this case wasAdded() and wasRemoved() will both return true.
Since:
JavaFX 2.0

  • Constructor Details

    • Change

      public Change​(ObservableMap<K,​V> map)
      Constructs a change associated with a map.
      Parameters:
      map - the source of the change

  • Method Details

    • getMap

      public ObservableMap<K,​V> getMap()
      An observable map that is associated with the change.
      Returns:
      the source map

    • wasAdded

      public abstract boolean wasAdded()
      If this change is a result of add operation.
      Returns:
      true if a new value (or key-value) entry was added to the map

    • wasRemoved

      public abstract boolean wasRemoved()
      If this change is a result of removal operation. Note that an element might be removed even as a result of put operation.
      Returns:
      true if an old value (or key-value) entry was removed from the map

    • getKey

      public abstract K getKey()
      A key associated with the change. If the change is a remove change, the key no longer exist in a map. Otherwise, the key got set to a new value.
      Returns:
      the key that changed

    • getValueAdded

      public abstract V getValueAdded()
      Get the new value of the key. Return null if this is a removal.
      Returns:
      the value that is now associated with the key

    • getValueRemoved

      public abstract V getValueRemoved()
      Get the old value of the key. This is null if and only if the value was added to the key that was not previously in the map.
      Returns:
      the value previously associated with the key