- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * 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.
- */
- /*
- * $Id: DTMAxisTraverser.java,v 1.4 2004/02/16 23:03:44 minchau Exp $
- */
- package com.sun.org.apache.xml.internal.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);
- }