xercesc/dom/DOMNodeFilter.hpp

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *      http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 /*
0019  * $Id$
0020  */
0021
0022 #if !defined(XERCESC_INCLUDE_GUARD_DOMNODEFILTER_HPP)
0023 #define XERCESC_INCLUDE_GUARD_DOMNODEFILTER_HPP
0024
0025 #include <xercesc/dom/DOMNode.hpp>
0026
0027 XERCES_CPP_NAMESPACE_BEGIN
0028
0029
0030 /**
0031  * Filters are objects that know how to "filter out" nodes. If a
0032  * <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> is given a
0033  * <code>DOMNodeFilter</code>, it applies the filter before it returns the next
0034  * node. If the filter says to accept the node, the traversal logic returns
0035  * it; otherwise, traversal looks for the next node and pretends that the
0036  * node that was rejected was not there.
0037  * <p>The DOM does not provide any filters. <code>DOMNodeFilter</code> is just an
0038  * interface that users can implement to provide their own filters.
0039  * <p><code>DOMNodeFilters</code> do not need to know how to traverse from node
0040  * to node, nor do they need to know anything about the data structure that
0041  * is being traversed. This makes it very easy to write filters, since the
0042  * only thing they have to know how to do is evaluate a single node. One
0043  * filter may be used with a number of different kinds of traversals,
0044  * encouraging code reuse.
0045  * <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>.
0046  * @since DOM Level 2
0047  */
0048
0049 class CDOM_EXPORT DOMNodeFilter
0050 {
0051 protected:
0052     // -----------------------------------------------------------------------
0053     //  Hidden constructors
0054     // -----------------------------------------------------------------------
0055     /** @name Hidden constructors */
0056     //@{
0057     DOMNodeFilter() {};
0058     //@}
0059
0060 private:
0061     // -----------------------------------------------------------------------
0062     // Unimplemented constructors and operators
0063     // -----------------------------------------------------------------------
0064     /** @name Unimplemented constructors and operators */
0065     //@{
0066     DOMNodeFilter(const DOMNodeFilter &);
0067     DOMNodeFilter & operator = (const DOMNodeFilter &);
0068     //@}
0069
0070 public:
0071     // -----------------------------------------------------------------------
0072     //  All constructors are hidden, just the destructor is available
0073     // -----------------------------------------------------------------------
0074     /** @name Destructor */
0075     //@{
0076     /**
0077      * Destructor
0078      *
0079      */
0080     virtual ~DOMNodeFilter() {};
0081     //@}
0082
0083     // -----------------------------------------------------------------------
0084     //  Class Types
0085     // -----------------------------------------------------------------------
0086     /** @name Public Constants */
0087     //@{
0088     /**
0089      * Constants returned by acceptNode.
0090      *
0091      * <p><code>FILTER_ACCEPT:</code>
0092      * Accept the node. Navigation methods defined for
0093      * <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> will return this
0094      * node.</p>
0095      *
0096      * <p><code>FILTER_REJECT:</code>
0097      * Reject the node. Navigation methods defined for
0098      * <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> will not return
0099      * this node. For <code>DOMTreeWalker</code>, the children of this node
0100      * will also be rejected. <code>DOMNodeIterators</code> treat this as a
0101      * synonym for <code>FILTER_SKIP.</code></p>
0102      *
0103      * <p><code>FILTER_SKIP:</code>
0104      * Skip this single node. Navigation methods defined for
0105      * <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> will not return
0106      * this node. For both <code>DOMNodeIterator</code> and
0107      * <code>DOMTreeWalker</code>, the children of this node will still be
0108      * considered.</p>
0109      *
0110      * @since DOM Level 2
0111      */
0112     enum FilterAction {FILTER_ACCEPT = 1,
0113                        FILTER_REJECT = 2,
0114                        FILTER_SKIP   = 3};
0115
0116     /**
0117      * Constants for whatToShow
0118      *
0119      * <p><code>SHOW_ALL:</code>
0120      * Show all <code>DOMNode(s)</code>.</p>
0121      *
0122      * <p><code>SHOW_ELEMENT:</code>
0123      * Show <code>DOMElement</code> nodes.</p>
0124      *
0125      * <p><code>SHOW_ATTRIBUTE:</code>
0126      * Show <code>DOMAttr</code> nodes. This is meaningful only when creating an
0127      * <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> with an
0128      * attribute node as its <code>root</code>; in this case, it means that
0129      * the attribute node will appear in the first position of the iteration
0130      * or traversal. Since attributes are never children of other nodes,
0131      * they do not appear when traversing over the document tree.</p>
0132      *
0133      * <p><code>SHOW_TEXT:</code>
0134      * Show <code>DOMText</code> nodes.</p>
0135      *
0136      * <p><code>SHOW_CDATA_SECTION:</code>
0137      * Show <code>DOMCDATASection</code> nodes.</p>
0138      *
0139      * <p><code>SHOW_ENTITY_REFERENCE:</code>
0140      * Show <code>DOMEntityReference</code> nodes.</p>
0141      *
0142      * <p><code>SHOW_ENTITY:</code>
0143      * Show <code>DOMEntity</code> nodes. This is meaningful only when creating
0144      * an <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> with an
0145      * <code>DOMEntity</code> node as its <code>root</code>; in this case, it
0146      * means that the <code>DOMEntity</code> node will appear in the first
0147      * position of the traversal. Since entities are not part of the
0148      * document tree, they do not appear when traversing over the document
0149      * tree.</p>
0150      *
0151      * <p><code>SHOW_PROCESSING_INSTRUCTION:</code>
0152      * Show <code>DOMProcessingInstruction</code> nodes.</p>
0153      *
0154      * <p><code>SHOW_COMMENT:</code>
0155      * Show <code>DOMComment</code> nodes.</p>
0156      *
0157      * <p><code>SHOW_DOCUMENT:</code>
0158      * Show <code>DOMDocument</code> nodes.</p>
0159      *
0160      * <p><code>SHOW_DOCUMENT_TYPE:</code>
0161      * Show <code>DOMDocumentType</code> nodes.</p>
0162      *
0163      * <p><code>SHOW_DOCUMENT_FRAGMENT:</code>
0164      * Show <code>DOMDocumentFragment</code> nodes.</p>
0165      *
0166      * <p><code>SHOW_NOTATION:</code>
0167      * Show <code>DOMNotation</code> nodes. This is meaningful only when creating
0168      * an <code>DOMNodeIterator</code> or <code>DOMTreeWalker</code> with a
0169      * <code>DOMNotation</code> node as its <code>root</code>; in this case, it
0170      * means that the <code>DOMNotation</code> node will appear in the first
0171      * position of the traversal. Since notations are not part of the
0172      * document tree, they do not appear when traversing over the document
0173      * tree.</p>
0174      *
0175      * @since DOM Level 2
0176      */
0177     enum ShowTypeMasks {
0178         SHOW_ALL                       = 0x0000FFFF,
0179         SHOW_ELEMENT                   = 0x00000001,
0180         SHOW_ATTRIBUTE                 = 0x00000002,
0181         SHOW_TEXT                      = 0x00000004,
0182         SHOW_CDATA_SECTION             = 0x00000008,
0183         SHOW_ENTITY_REFERENCE          = 0x00000010,
0184         SHOW_ENTITY                    = 0x00000020,
0185         SHOW_PROCESSING_INSTRUCTION    = 0x00000040,
0186         SHOW_COMMENT                   = 0x00000080,
0187         SHOW_DOCUMENT                  = 0x00000100,
0188         SHOW_DOCUMENT_TYPE             = 0x00000200,
0189         SHOW_DOCUMENT_FRAGMENT         = 0x00000400,
0190         SHOW_NOTATION                  = 0x00000800
0191     };
0192
0193     typedef unsigned long ShowType;
0194
0195     //@}
0196
0197     // -----------------------------------------------------------------------
0198     //  Virtual DOMNodeFilter interface
0199     // -----------------------------------------------------------------------
0200     /** @name Functions introduced in DOM Level 2 */
0201     //@{
0202     /**
0203      * Test whether a specified node is visible in the logical view of a
0204      * <code>DOMTreeWalker</code> or <code>DOMNodeIterator</code>. This function
0205      * will be called by the implementation of <code>DOMTreeWalker</code> and
0206      * <code>DOMNodeIterator</code>; it is not normally called directly from
0207      * user code. (Though you could do so if you wanted to use the same
0208      * filter to guide your own application logic.)
0209      * @param node The node to check to see if it passes the filter or not.
0210      * @return A constant to determine whether the node is accepted,
0211      *   rejected, or skipped, as defined above.
0212      * @since DOM Level 2
0213      */
0214     virtual FilterAction acceptNode (const DOMNode* node) const =0;
0215     //@}
0216
0217 };
0218
0219 XERCES_CPP_NAMESPACE_END
0220
0221 #endif