ObservableMergers.java 文件源码

@SafeVarargs
public static <T, E> void mergeSet(Function<? super E, ? extends T> mapper,
    ObservableSet<T> into, ObservableSet<E>... sets) {
    final ObservableSet<T> set = into;
    for (ObservableSet<E> s : sets) {
        for (E item : s) {
            set.add(mapper.apply(item));
        }
        s.addListener((SetChangeListener<E>) c -> {
            if (c.wasAdded()) {
                set.add(mapper.apply(c.getElementAdded()));
            }
            if (c.wasRemoved()) {
                set.remove(mapper.apply(c.getElementRemoved()));
            }
        });
    }
}