io.ebean.common.ModifyListIterator Maven / Gradle / Ivy
package io.ebean.common;
import io.ebean.bean.BeanCollection;
import java.util.ListIterator;
/**
* Wraps a ListIterator for the purposes of notifying removals and additions to
* the BeanCollection owner.
*
* This is required for persisting ManyToMany objects. Additions and removals
* become inserts and deletes to the intersection table.
*
*/
class ModifyListIterator implements ListIterator {
private final BeanCollection owner;
private final ListIterator it;
private E last;
/**
* Create with an Owner that is notified of any additions or deletions.
*/
ModifyListIterator(BeanCollection owner, ListIterator it) {
this.owner = owner;
this.it = it;
}
@Override
public void add(E bean) {
owner.modifyAddition(bean);
last = null;
it.add(bean);
}
@Override
public boolean hasNext() {
return it.hasNext();
}
@Override
public boolean hasPrevious() {
return it.hasPrevious();
}
@Override
public E next() {
last = it.next();
return last;
}
@Override
public int nextIndex() {
return it.nextIndex();
}
@Override
public E previous() {
last = it.previous();
return last;
}
@Override
public int previousIndex() {
return it.previousIndex();
}
@Override
public void remove() {
owner.modifyRemoval(last);
last = null;
it.remove();
}
@Override
public void set(E o) {
if (last != null) {
owner.modifyRemoval(last);
owner.modifyAddition(o);
}
it.set(o);
}
}