/**
* Creates a new {@link ListProperty>} of type {@code F}.
*
* <p>Only changes in this list will be reflected in the returned list, e.g. it's a one way
* conversion.
*/
public <F> ListProperty<F> map(final ElementMapper<E, F> mapper) {
// make an intial copy of all the elements currently in our list
List<F> initial = null;
if (get() != null) {
initial = new ArrayList<F>();
for (E e : get()) {
initial.add(mapper.map(e));
}
}
final ListProperty<F> mapped = listProperty(getName(), initial);
// keep converting E -> F into as
addListChangedHandler(
new ListChangedHandler<E>() {
public void onListChanged(ListChangedEvent<E> event) {
if (get() != null && mapped.get() == null) {
mapped.setInitialValue(new ArrayList<F>());
}
event
.getDiff()
.apply(
mapped.getDirect(),
new ListDiff.Mapper<E, F>() {
public F map(E e) {
return mapper.map(e);
}
});
if (isTouched() && !mapped.isTouched()) {
mapped.setTouched(true);
} else {
mapped.reassess();
}
}
});
return mapped;
}
/**
* Sorts our values by {@code comparator} (and continually applies the comparator as new values
* are added/removed/set).
*/
public void setComparator(Comparator<E> comparator) {
this.persistentComparator = comparator;
List<E> copy = copyLastValue(getDirect());
if (copy != null && !copy.equals(getDirect())) {
set(copy);
}
}
/**
* Checks equality between a and b by ignoring list order.
*
* <p>This is because a frequent use case of "listA.is(listB)" is for "Select All" functionality,
* and if a user selects items in a different order, we still want to consider listA equal to
* listB.
*/
@Override
protected boolean isEqual(List<E> a, List<E> b) {
if (ObjectUtils.eq(a, b)) {
return true;
} else if (a != null && b != null && a.size() == b.size()) {
List<E> b2 = new ArrayList<E>(b);
for (E e : a) {
if (!b2.remove(e)) {
return false;
}
}
return true;
} else {
return false;
}
}
@Override
public String toString() {
List<E> e = getDirect();
if (e == null) {
return getValueObject().getName() + " null";
}
// Janky, but keep ListProperty.toString from being huge and accidentally ruining perf
String s = getValueObject().getName() + " [";
for (int i = 0; i < e.size() && i < 20; i++) {
s += ObjectUtils.toStr(e.get(i), "null");
if (i != e.size() - 1) {
s += ", ";
}
}
if (e.size() > 20) {
s += "...";
}
s += "]";
return s;
}
/**
* Creates a new {@link ListProperty>} of type {@code F}.
*
* <p>Any changes made to either list will be reflected in the other, using {@code converter} to
* go between {@code E} and {@code F}.
*/
public <F> ListProperty<F> as(final ElementConverter<E, F> converter) {
// make an intial copy of all the elements currently in our list
List<F> initial = null;
if (get() != null) {
initial = new ArrayList<F>();
for (E e : get()) {
F f = converter.to(e);
initial.add(f);
}
}
final ListProperty<F> as = listProperty(getName(), initial);
final boolean[] active = {false};
// keep converting E -> F into as
addListChangedHandler(
new ListChangedHandler<E>() {
public void onListChanged(ListChangedEvent<E> event) {
if (!active[0]) {
active[0] = true;
if (get() != null && as.get() == null) {
as.setInitialValue(new ArrayList<F>());
}
event
.getDiff()
.apply(
as.getDirect(),
new ListDiff.Mapper<E, F>() {
public F map(E e) {
return converter.to(e);
}
});
if (isTouched() && !as.isTouched()) {
as.setTouched(true);
} else {
as.reassess();
}
active[0] = false;
}
}
});
// also convert new Fs back into Es
as.addListChangedHandler(
new ListChangedHandler<F>() {
public void onListChanged(ListChangedEvent<F> event) {
if (!active[0]) {
active[0] = true;
if (get() == null && as.get() != null) {
setInitialValue(new ArrayList<E>());
}
event
.getDiff()
.apply(
getDirect(),
new ListDiff.Mapper<F, E>() {
public E map(F f) {
return converter.from(f);
}
});
if (as.isTouched() && !isTouched()) {
setTouched(true);
} else {
reassess();
}
active[0] = false;
}
}
});
return as;
}