/**
* Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright ownership. Apereo
* licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
* this file except in compliance with the License. You may obtain a copy of the License at the
* following location:
*
* <p>http://www.apache.org/licenses/LICENSE-2.0
*
* <p>Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apereo.portal.utils;
import com.google.common.base.Function;
import com.google.common.collect.ForwardingList;
import java.util.Collection;
/**
* List that runs each element being added through a fitler before adding it
*
* @param <E>
*/
public abstract class FilteringOnAddList<E> extends ForwardingList<E> {
private final Function<E, E> filterAdd;
private final boolean ignoreNull;
public FilteringOnAddList(Function<E, E> filterAdd, boolean ignoreNull) {
this.filterAdd = filterAdd;
this.ignoreNull = ignoreNull;
}
@Override
public boolean add(E element) {
element = this.filterAdd.apply(element);
if (element == null && ignoreNull) {
return false;
}
return super.add(element);
}
@Override
public boolean addAll(Collection<? extends E> collection) {
boolean modified = false;
for (final E element : collection) {
modified = this.add(element) || modified;
}
return modified;
}
@Override
public void add(int index, E element) {
element = this.filterAdd.apply(element);
if (element == null && ignoreNull) {
return;
}
super.add(index, element);
}
@Override
public boolean addAll(int index, Collection<? extends E> elements) {
final int size = this.size();
for (final E element : elements) {
this.add(index, element);
index++;
}
return size != this.size();
}
}