Module javafx.base
Package javafx.collections

Class 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 Detail

      • Change

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

    • Method Detail

      • 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