/** @return a two-way property of whether {@code items} are a subset of this list. */
public BooleanProperty containsAll(final List<E> items) {
final BooleanProperty b = booleanProperty(getName() + "ContainsAll", false);
final boolean[] firing = {false};
// conditionally update us when b goes true->false/false->true
b.addPropertyChangedHandler(
new PropertyChangedHandler<Boolean>() {
public void onPropertyChanged(final PropertyChangedEvent<Boolean> event) {
if (!firing[0]) {
firing[0] = true;
if (event.getNewValue()) {
for (final E item : items) {
if (!get().contains(item)) {
add(item);
}
}
} else {
removeAll(items);
}
firing[0] = false;
}
}
});
// conditionally update b when we change
addPropertyChangedHandler(
new PropertyChangedHandler<List<E>>() {
public void onPropertyChanged(final PropertyChangedEvent<List<E>> event) {
if (!firing[0]) {
firing[0] = true;
b.set(get().containsAll(items));
firing[0] = false;
}
}
});
return b;
}
