EventStreams.java 文件源码

public static <T> EventStream<SetChangeListener.Change<? extends T>> changesOf(ObservableSet<T> set) {
    return new EventStreamBase<SetChangeListener.Change<? extends T>>() {
        @Override
        protected Subscription observeInputs() {
            SetChangeListener<T> listener = c -> emit(c);
            set.addListener(listener);
            return () -> set.removeListener(listener);
        }
    };
}