/*

 * 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.

 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file and, per its terms, should not be removed:

 *

 * Copyright (c) 2000 World Wide Web Consortium,

 * (Massachusetts Institute of Technology, Institut National de

 * Recherche en Informatique et en Automatique, Keio University). All

 * Rights Reserved. This program is distributed under the W3C's Software

 * Intellectual Property License. This program 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 W3C License http://www.w3.org/Consortium/Legal/ for more details.

 */

package org.w3c.dom.traversal;

import org.w3c.dom.Node;

/**

 * Filters are objects that know how to "filter out" nodes. If a

 * <code>NodeIterator</code> or <code>TreeWalker</code> is given a

 * <code>NodeFilter</code>, it applies the filter before it returns the next

 * node. If the filter says to accept the node, the traversal logic returns

 * it; otherwise, traversal looks for the next node and pretends that the

 * node that was rejected was not there.

 * <p>The DOM does not provide any filters. <code>NodeFilter</code> is just an

 * interface that users can implement to provide their own filters.

 * <p><code>NodeFilters</code> do not need to know how to traverse from node

 * to node, nor do they need to know anything about the data structure that

 * is being traversed. This makes it very easy to write filters, since the

 * only thing they have to know how to do is evaluate a single node. One

 * filter may be used with a number of different kinds of traversals,

 * encouraging code reuse.

 * <p>See also the <a href='http://www.w3.org/TR/2000/REC-DOM-Level-2-Traversal-Range-20001113'>Document Object Model (DOM) Level 2 Traversal and Range Specification</a>.

 * @since 9, DOM Level 2

 */

public interface NodeFilter {

    // Constants returned by acceptNode

    /**

     * Accept the node. Navigation methods defined for

     * <code>NodeIterator</code> or <code>TreeWalker</code> will return this

     * node.

     */

    public static final short FILTER_ACCEPT             = 1;

    /**

     * Reject the node. Navigation methods defined for

     * <code>NodeIterator</code> or <code>TreeWalker</code> will not return

     * this node. For <code>TreeWalker</code>, the children of this node

     * will also be rejected. <code>NodeIterators</code> treat this as a

     * synonym for <code>FILTER_SKIP</code>.

     */

    public static final short FILTER_REJECT             = 2;

    /**

     * Skip this single node. Navigation methods defined for

     * <code>NodeIterator</code> or <code>TreeWalker</code> will not return

     * this node. For both <code>NodeIterator</code> and

     * <code>TreeWalker</code>, the children of this node will still be

     * considered.

     */

    public static final short FILTER_SKIP               = 3;

    // Constants for whatToShow

    /**

     * Show all <code>Nodes</code>.

     */

    public static final int SHOW_ALL                  = 0xFFFFFFFF;

    /**

     * Show <code>Element</code> nodes.

     */

    public static final int SHOW_ELEMENT              = 0x00000001;

    /**

     * Show <code>Attr</code> nodes. This is meaningful only when creating an

     * <code>NodeIterator</code> or <code>TreeWalker</code> with an

     * attribute node as its <code>root</code>; in this case, it means that

     * the attribute node will appear in the first position of the iteration

     * or traversal. Since attributes are never children of other nodes,

     * they do not appear when traversing over the document tree.

     */

    public static final int SHOW_ATTRIBUTE            = 0x00000002;

    /**

     * Show <code>Text</code> nodes.

     */

    public static final int SHOW_TEXT                 = 0x00000004;

    /**

     * Show <code>CDATASection</code> nodes.

     */

    public static final int SHOW_CDATA_SECTION        = 0x00000008;

    /**

     * Show <code>EntityReference</code> nodes.

     */

    public static final int SHOW_ENTITY_REFERENCE     = 0x00000010;

    /**

     * Show <code>Entity</code> nodes. This is meaningful only when creating

     * an <code>NodeIterator</code> or <code>TreeWalker</code> with an

     * <code>Entity</code> node as its <code>root</code>; in this case, it

     * means that the <code>Entity</code> node will appear in the first

     * position of the traversal. Since entities are not part of the

     * document tree, they do not appear when traversing over the document

     * tree.

     */

    public static final int SHOW_ENTITY               = 0x00000020;

    /**

     * Show <code>ProcessingInstruction</code> nodes.

     */

    public static final int SHOW_PROCESSING_INSTRUCTION = 0x00000040;

    /**

     * Show <code>Comment</code> nodes.

     */

    public static final int SHOW_COMMENT              = 0x00000080;

    /**

     * Show <code>Document</code> nodes.

     */

    public static final int SHOW_DOCUMENT             = 0x00000100;

    /**

     * Show <code>DocumentType</code> nodes.

     */

    public static final int SHOW_DOCUMENT_TYPE        = 0x00000200;

    /**

     * Show <code>DocumentFragment</code> nodes.

     */

    public static final int SHOW_DOCUMENT_FRAGMENT    = 0x00000400;

    /**

     * Show <code>Notation</code> nodes. This is meaningful only when creating

     * an <code>NodeIterator</code> or <code>TreeWalker</code> with a

     * <code>Notation</code> node as its <code>root</code>; in this case, it

     * means that the <code>Notation</code> node will appear in the first

     * position of the traversal. Since notations are not part of the

     * document tree, they do not appear when traversing over the document

     * tree.

     */

    public static final int SHOW_NOTATION             = 0x00000800;

    /**

     * Test whether a specified node is visible in the logical view of a

     * <code>TreeWalker</code> or <code>NodeIterator</code>. This function

     * will be called by the implementation of <code>TreeWalker</code> and

     * <code>NodeIterator</code>; it is not normally called directly from

     * user code. (Though you could do so if you wanted to use the same

     * filter to guide your own application logic.)

     * @param n The node to check to see if it passes the filter or not.

     * @return A constant to determine whether the node is accepted,

     *   rejected, or skipped, as defined above.

     */

    public short acceptNode(Node n);

}