PropertyUtils.java 文件源码

/**
 * Binds a property to a specific key in a map. If there is no entry for that key, the property's
 * value will be set to null.
 *
 * @param property the property to bind
 * @param map      the map to bind to
 * @param key      the key for the entry to bind to
 * @param v2t      a conversion function for converting objects of type <i>V</i> to type <i>T</i>
 * @param <K>      the types of the keys in the map
 * @param <V>      the types of the values in the map
 * @param <T>      the type of data in the property
 */
public static <K, V, T extends V> void bindToMapBidirectionally(Property<T> property,
                                                                ObservableMap<K, V> map,
                                                                K key,
                                                                Function<V, T> v2t) {
  property.addListener((__, oldValue, newValue) -> map.put(key, newValue));
  map.addListener((MapChangeListener<K, V>) change -> {
    if (change.getKey().equals(key)) {
      if (change.wasRemoved() && !map.containsKey(key)) {
        property.setValue(null);
      } else if (change.wasAdded()) {
        property.setValue(v2t.apply(change.getValueAdded()));
      }
    }
  });
}