nl.vpro.util.ResortedSortedSet Maven / Gradle / Ivy
package nl.vpro.util;
import java.io.Serial;
import java.io.Serializable;
import java.util.*;
import java.util.function.Consumer;
import org.checkerframework.checker.nullness.qual.NonNull;
/**
* A modifiable SortedSet, that wraps another collection (changes are reflected), with an explicit sort order.
* @author Michiel Meeuwissen
* @since 2.1
*/
public class ResortedSortedSet extends AbstractSet implements SortedSet, Serializable {
@Serial
private static final long serialVersionUID = 0L;
final Collection wrapped;
final SortedSet set;
final Consumer[] addListeners;
@SafeVarargs
public ResortedSortedSet(Collection wrapped, Comparator comparator, Consumer... addListeners) {
set = new TreeSet<>(comparator);
set.addAll(wrapped);
this.wrapped = wrapped;
this.addListeners = addListeners;
}
@SafeVarargs
private ResortedSortedSet(Collection wrapped, SortedSet set, Consumer... addListeners) {
this.set = set;
set.addAll(wrapped);
this.wrapped = wrapped;
this.addListeners = addListeners;
}
public static > ResortedSortedSet of(
Collection wrapped, Consumer... addListener) {
return new ResortedSortedSet<>(wrapped, new TreeSet<>(), addListener);
}
@SafeVarargs
public ResortedSortedSet(SortedSet set, Collection wrapped, Consumer... addListeners) {
this.set = set;
this.wrapped = wrapped;
this.addListeners = addListeners;
}
@NonNull
@Override
public Iterator iterator() {
final Iterator i = set.iterator();
return new Iterator() {
T lastElement;
boolean hasElementToRemove = false;
@Override
public boolean hasNext() {
return i.hasNext();
}
@Override
public T next() {
lastElement = i.next();
hasElementToRemove = true;
return lastElement;
}
@Override
public void remove() {
i.remove();
if (hasElementToRemove) {
wrapped.remove(lastElement);
hasElementToRemove = false;
} else {
throw new IllegalStateException();
}
}
};
}
@Override
public int size() {
return set.size();
}
@Override
public boolean add(T element) {
boolean result = set.add(element);
if (result) {
wrapped.add(element);
for (Consumer addListener : addListeners) {
addListener.accept(element);
}
}
return result;
}
@Override
public Comparator comparator() {
return set.comparator();
}
@NonNull
@Override
public SortedSet subSet(T fromElement, T toElement) {
return new ResortedSortedSet<>(set.subSet(fromElement, toElement), wrapped);
}
@NonNull
@Override
public SortedSet headSet(T toElement) {
return new ResortedSortedSet<>(set.headSet(toElement), wrapped);
}
@NonNull
@Override
public SortedSet tailSet(T fromElement) {
return new ResortedSortedSet<>(set.tailSet(fromElement), wrapped);
}
@Override
public T first() {
return set.first();
}
@Override
public T last() {
return set.last();
}
}