| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 1999-2003 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xalan" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
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| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 1999, Lotus |
| * Development Corporation., http://www.lotus.com. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.xml.dtm; |
| |
| /** |
| * A class that implements traverses DTMAxisTraverser interface can traverse |
| * a set of nodes, usually as defined by an XPath axis. It is different from |
| * an iterator, because it does not need to hold state, and, in fact, must not |
| * hold any iteration-based state. It is meant to be implemented as an inner |
| * class of a DTM, and returned by the getAxisTraverser(final int axis) |
| * function. |
| * |
| * <p>A DTMAxisTraverser can probably not traverse a reverse axis in |
| * document order.</p> |
| * |
| * <p>Typical usage:</p> |
| * <pre><code> |
| * for(int nodeHandle=myTraverser.first(myContext); |
| * nodeHandle!=DTM.NULL; |
| * nodeHandle=myTraverser.next(myContext,nodeHandle)) |
| * { ... processing for node indicated by nodeHandle goes here ... } |
| * </code></pre> |
| * |
| * @author Scott Boag |
| */ |
| public abstract class DTMAxisTraverser |
| { |
| |
| /** |
| * By the nature of the stateless traversal, the context node can not be |
| * returned or the iteration will go into an infinate loop. So to traverse |
| * an axis, the first function must be used to get the first node. |
| * |
| * <p>This method needs to be overloaded only by those axis that process |
| * the self node. <\p> |
| * |
| * @param context The context node of this traversal. This is the point |
| * that the traversal starts from. |
| * @return the first node in the traversal. |
| */ |
| public int first(int context) |
| { |
| return next(context, context); |
| } |
| |
| /** |
| * By the nature of the stateless traversal, the context node can not be |
| * returned or the iteration will go into an infinate loop. So to traverse |
| * an axis, the first function must be used to get the first node. |
| * |
| * <p>This method needs to be overloaded only by those axis that process |
| * the self node. <\p> |
| * |
| * @param context The context node of this traversal. This is the point |
| * of origin for the traversal -- its "root node" or starting point. |
| * @param extendedTypeID The extended type ID that must match. |
| * |
| * @return the first node in the traversal. |
| */ |
| public int first(int context, int extendedTypeID) |
| { |
| return next(context, context, extendedTypeID); |
| } |
| |
| /** |
| * Traverse to the next node after the current node. |
| * |
| * @param context The context node of this traversal. This is the point |
| * of origin for the traversal -- its "root node" or starting point. |
| * @param current The current node of the traversal. This is the last known |
| * location in the traversal, typically the node-handle returned by the |
| * previous traversal step. For the first traversal step, context |
| * should be set equal to current. Note that in order to test whether |
| * context is in the set, you must use the first() method instead. |
| * |
| * @return the next node in the iteration, or DTM.NULL. |
| * @see first(int) |
| */ |
| public abstract int next(int context, int current); |
| |
| /** |
| * Traverse to the next node after the current node that is matched |
| * by the extended type ID. |
| * |
| * @param context The context node of this traversal. This is the point |
| * of origin for the traversal -- its "root node" or starting point. |
| * @param current The current node of the traversal. This is the last known |
| * location in the traversal, typically the node-handle returned by the |
| * previous traversal step. For the first traversal step, context |
| * should be set equal to current. Note that in order to test whether |
| * context is in the set, you must use the first() method instead. |
| * @param extendedTypeID The extended type ID that must match. |
| * |
| * @return the next node in the iteration, or DTM.NULL. |
| * @see first(int,int) |
| */ |
| public abstract int next(int context, int current, int extendedTypeID); |
| } |