com.phloc.commons.parent.IHasChildrenSorted 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;
import java.util.List;
import javax.annotation.Nonnegative;
import javax.annotation.Nullable;
/**
* Extends {@link IHasChildren} by indicating that the child items are sorted!
*
* @author Philip Helger
* @param
* The type of the children.
*/
public interface IHasChildrenSorted extends IHasChildren
{
/**
* @return A ordered list of child elements. May be null if no
* children are present.
*/
@Nullable
List getChildren ();
/**
* Get the child node at the specified index
*
* @param nIndex
* The index to be queried. May not be < 0 or ≥ the number of
* children
* @return The child at the specified index or null if the index
* is invalid.
* @throws IndexOutOfBoundsException
* in case the index is invalid
*/
@Nullable
CHILDTYPE getChildAtIndex (@Nonnegative int nIndex);
/**
* Get the first child node or null if no child is present
*
* @return The first child or null.
*/
@Nullable
CHILDTYPE getFirstChild ();
/**
* Get the last child node or null if no child is present
*
* @return The last child or null.
*/
@Nullable
CHILDTYPE getLastChild ();
}