001    /*
002     * Copyright (c) 2007 Henri Sivonen
003     * Copyright (c) 2008 Mozilla Foundation
004     *
005     * Permission is hereby granted, free of charge, to any person obtaining a 
006     * copy of this software and associated documentation files (the "Software"), 
007     * to deal in the Software without restriction, including without limitation 
008     * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
009     * and/or sell copies of the Software, and to permit persons to whom the 
010     * Software is furnished to do so, subject to the following conditions:
011     *
012     * The above copyright notice and this permission notice shall be included in 
013     * all copies or substantial portions of the Software.
014     *
015     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
016     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
017     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
018     * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
019     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
020     * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
021     * DEALINGS IN THE SOFTWARE.
022     */
023    
024    package nu.validator.saxtree;
025    
026    import org.xml.sax.Attributes;
027    import org.xml.sax.ContentHandler;
028    import org.xml.sax.Locator;
029    import org.xml.sax.SAXException;
030    import org.xml.sax.ext.LexicalHandler;
031    
032    /**
033     * A tree visitor that replays a tree as SAX events.
034     * @version $Id$
035     * @author hsivonen
036     */
037    public final class TreeParser implements Locator {
038        
039        /**
040         * The content handler.
041         */
042        private final ContentHandler contentHandler;
043    
044        /**
045         * The lexical handler.
046         */
047        private final LexicalHandler lexicalHandler;
048    
049        /**
050         * The current locator.
051         */
052        private Locator locatorDelegate;
053    
054        /**
055         * The constructor.
056         * 
057         * @param contentHandler
058         *            must not be <code>null</code>
059         * @param lexicalHandler
060         *            may be <code>null</code>
061         */
062        public TreeParser(final ContentHandler contentHandler,
063                final LexicalHandler lexicalHandler) {
064            if (contentHandler == null) {
065                throw new IllegalArgumentException("contentHandler was null.");
066            }
067            this.contentHandler = contentHandler;
068            if (lexicalHandler == null) {
069                this.lexicalHandler = new NullLexicalHandler();
070            } else {
071                this.lexicalHandler = lexicalHandler;
072            }
073        }
074    
075        /**
076         * Causes SAX events for the tree rooted at the argument to be emitted.
077         * <code>startDocument()</code> and <code>endDocument()</code> are only
078         * emitted for a <code>Document</code> node.
079         * 
080         * @param node
081         *            the root
082         * @throws SAXException
083         */
084        public void parse(Node node) throws SAXException {
085            contentHandler.setDocumentLocator(this);
086            Node current = node;
087            Node next;
088            for (;;) {
089                current.visit(this);
090                if ((next = current.getFirstChild()) != null) {
091                    current = next;
092                    continue;
093                }
094                for (;;) {
095                    current.revisit(this);
096                    if (current == node) {
097                        return;
098                    }
099                    if ((next = current.getNextSibling()) != null) {
100                        current = next;
101                        break;
102                    }
103                    current = current.getParentNode();
104                }
105            }
106        }
107    
108        /**
109         * @see org.xml.sax.ContentHandler#characters(char[], int, int)
110         */
111        void characters(char[] ch, int start, int length, Locator locator)
112                throws SAXException {
113            this.locatorDelegate = locator;
114            contentHandler.characters(ch, start, length);
115        }
116    
117        /**
118         * @see org.xml.sax.ContentHandler#endDocument()
119         */
120        void endDocument(Locator locator) throws SAXException {
121            this.locatorDelegate = locator;
122            contentHandler.endDocument();
123        }
124    
125        /**
126         * @see org.xml.sax.ContentHandler#endElement(java.lang.String,
127         *      java.lang.String, java.lang.String)
128         */
129        void endElement(String uri, String localName, String qName, Locator locator)
130                throws SAXException {
131            this.locatorDelegate = locator;
132            contentHandler.endElement(uri, localName, qName);
133        }
134    
135        /**
136         * @see org.xml.sax.ContentHandler#endPrefixMapping(java.lang.String)
137         */
138        void endPrefixMapping(String prefix, Locator locator) throws SAXException {
139            this.locatorDelegate = locator;
140            contentHandler.endPrefixMapping(prefix);
141        }
142    
143        /**
144         * @see org.xml.sax.ContentHandler#ignorableWhitespace(char[], int, int)
145         */
146        void ignorableWhitespace(char[] ch, int start, int length, Locator locator)
147                throws SAXException {
148            this.locatorDelegate = locator;
149            contentHandler.ignorableWhitespace(ch, start, length);
150        }
151    
152        /**
153         * @see org.xml.sax.ContentHandler#processingInstruction(java.lang.String,
154         *      java.lang.String)
155         */
156        void processingInstruction(String target, String data, Locator locator)
157                throws SAXException {
158            this.locatorDelegate = locator;
159            contentHandler.processingInstruction(target, data);
160        }
161    
162        /**
163         * @see org.xml.sax.ContentHandler#skippedEntity(java.lang.String)
164         */
165        void skippedEntity(String name, Locator locator) throws SAXException {
166            this.locatorDelegate = locator;
167            contentHandler.skippedEntity(name);
168        }
169    
170        /**
171         * @see org.xml.sax.ContentHandler#startDocument()
172         */
173        void startDocument(Locator locator) throws SAXException {
174            this.locatorDelegate = locator;
175            contentHandler.startDocument();
176        }
177    
178        /**
179         * @see org.xml.sax.ContentHandler#startElement(java.lang.String,
180         *      java.lang.String, java.lang.String, org.xml.sax.Attributes)
181         */
182        void startElement(String uri, String localName, String qName,
183                Attributes atts, Locator locator) throws SAXException {
184            this.locatorDelegate = locator;
185            contentHandler.startElement(uri, localName, qName, atts);
186        }
187    
188        /**
189         * @see org.xml.sax.ContentHandler#startPrefixMapping(java.lang.String,
190         *      java.lang.String)
191         */
192        void startPrefixMapping(String prefix, String uri, Locator locator)
193                throws SAXException {
194            this.locatorDelegate = locator;
195            contentHandler.startPrefixMapping(prefix, uri);
196        }
197    
198        /**
199         * @see org.xml.sax.ext.LexicalHandler#comment(char[], int, int)
200         */
201        void comment(char[] ch, int start, int length, Locator locator)
202                throws SAXException {
203            this.locatorDelegate = locator;
204            lexicalHandler.comment(ch, start, length);
205        }
206    
207        /**
208         * @see org.xml.sax.ext.LexicalHandler#endCDATA()
209         */
210        void endCDATA(Locator locator) throws SAXException {
211            this.locatorDelegate = locator;
212            lexicalHandler.endCDATA();
213        }
214    
215        /**
216         * @see org.xml.sax.ext.LexicalHandler#endDTD()
217         */
218        void endDTD(Locator locator) throws SAXException {
219            this.locatorDelegate = locator;
220            lexicalHandler.endDTD();
221        }
222    
223        /**
224         * @see org.xml.sax.ext.LexicalHandler#endEntity(java.lang.String)
225         */
226        void endEntity(String name, Locator locator) throws SAXException {
227            this.locatorDelegate = locator;
228            lexicalHandler.endEntity(name);
229        }
230    
231        /**
232         * @see org.xml.sax.ext.LexicalHandler#startCDATA()
233         */
234        void startCDATA(Locator locator) throws SAXException {
235            this.locatorDelegate = locator;
236            lexicalHandler.startCDATA();
237        }
238    
239        /**
240         * @see org.xml.sax.ext.LexicalHandler#startDTD(java.lang.String,
241         *      java.lang.String, java.lang.String)
242         */
243        void startDTD(String name, String publicId, String systemId, Locator locator)
244                throws SAXException {
245            this.locatorDelegate = locator;
246            lexicalHandler.startDTD(name, publicId, systemId);
247        }
248    
249        /**
250         * @see org.xml.sax.ext.LexicalHandler#startEntity(java.lang.String)
251         */
252        void startEntity(String name, Locator locator) throws SAXException {
253            this.locatorDelegate = locator;
254            lexicalHandler.startEntity(name);
255        }
256    
257        /**
258         * @see org.xml.sax.Locator#getColumnNumber()
259         */
260        public int getColumnNumber() {
261            if (locatorDelegate == null) {
262                return -1;
263            } else {
264                return locatorDelegate.getColumnNumber();
265            }
266        }
267    
268        /**
269         * @see org.xml.sax.Locator#getLineNumber()
270         */
271        public int getLineNumber() {
272            if (locatorDelegate == null) {
273                return -1;
274            } else {
275                return locatorDelegate.getLineNumber();
276            }
277        }
278    
279        /**
280         * @see org.xml.sax.Locator#getPublicId()
281         */
282        public String getPublicId() {
283            if (locatorDelegate == null) {
284                return null;
285            } else {
286    
287                return locatorDelegate.getPublicId();
288            }
289        }
290    
291        /**
292         * @see org.xml.sax.Locator#getSystemId()
293         */
294        public String getSystemId() {
295            if (locatorDelegate == null) {
296                return null;
297            } else {
298                return locatorDelegate.getSystemId();
299            }
300        }
301    }