com.phloc.commons.parent.impl.ChildrenProviderHasChildrenSorting Maven / Gradle / Ivy
/**
* Copyright (C) 2006-2015 phloc systems
* http://www.phloc.com
* office[at]phloc[dot]com
*
* Licensed 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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 com.phloc.commons.parent.impl;
import java.util.Collection;
import java.util.Comparator;
import java.util.List;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;
import com.phloc.commons.ValueEnforcer;
import com.phloc.commons.collections.ContainerHelper;
import com.phloc.commons.parent.IHasChildren;
/**
* An implementation of the {@link com.phloc.commons.parent.IChildrenProvider}
* interface that works with all types that implement
* {@link com.phloc.commons.parent.IHasChildren}. It automatically sorts the
* returned children by the specified comparator.
*
* @author Philip Helger
* @param
* The data type of the child objects.
*/
@Immutable
public class ChildrenProviderHasChildrenSorting > extends ChildrenProviderHasChildren
{
private final Comparator m_aComparator;
public ChildrenProviderHasChildrenSorting (@Nonnull final Comparator aComparator)
{
m_aComparator = ValueEnforcer.notNull (aComparator, "Comparator");
}
@Override
@Nullable
public List getChildren (@Nullable final CHILDTYPE aCurrent)
{
// Get all children of the passed element
final Collection ret = aCurrent == null ? null : aCurrent.getChildren ();
// If there is anything to sort do it now
return ret == null ? null : ContainerHelper.getSorted (ret, m_aComparator);
}
}