Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * Copyright (c) 2015 World Wide Web Consortium, * * (Massachusetts Institute of Technology, European Research Consortium for * Informatics and Mathematics, Keio University, Beihang). All Rights Reserved. * This work is distributed under the W3C(r) Software License [1] in the hope that * it will be useful, but WITHOUT ANY WARRANTY; without even the implied * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * * [1] http://www.w3.org/Consortium/Legal/copyright-software */ package org.w3c.dom; /** * The {@code ElementTraversal} interface is a set of read-only attributes * which allow an author to easily navigate between elements in a document. * <p> * In conforming implementations of Element Traversal, all objects that * implement {@link Element} must also implement the {@code ElementTraversal} * interface. Four of the methods, * {@link #getFirstElementChild}, {@link #getLastElementChild}, * {@link #getPreviousElementSibling}, and {@link #getNextElementSibling}, * each provides a live reference to another element with the defined * relationship to the current element, if the related element exists. The * fifth method, {@link #getChildElementCount}, exposes the number of child * elements of an element, for preprocessing before navigation. * * @see * <a href='http://www.w3.org/TR/ElementTraversal/'><cite>Element Traversal Specification</cite></a> * * @since 9 */ public interface ElementTraversal { /** * Returns a reference to the first child node of the element which is of * the {@link Element} type. * * @return a reference to an element child, {@code null} if the element has * no child of the {@link Element} type. */ Element getFirstElementChild(); /** * Returns a reference to the last child node of the element which is of * the {@link Element} type. * * @return a reference to an element child, {@code null} if the element has * no child of the {@link Element} type. */ Element getLastElementChild(); /** * Returns a reference to the sibling node of the element which most immediately * precedes the element in document order, and which is of the {@link Element} type. * * @return a reference to an element child, {@code null} if the element has * no sibling node of the {@link Element} type that comes before this one. */ Element getPreviousElementSibling(); /** * Returns a reference to the sibling node of the element which most immediately * follows the element in document order, and which is of the {@link Element} type. * * @return a reference to an element child, {@code null} if the element has * no sibling node of the {@link Element} type that comes after this one. */ Element getNextElementSibling(); /** * Returns the current number of child nodes of the element which are of * the {@link Element} type. * * @return the number of element children, or {@code 0} if the element has * no element children. */ int getChildElementCount(); }