001 /**
002 * Java Gui Builder - A library to build GUIs using an XML file.
003 * Copyright 2002, 2003 (C) François Beausoleil
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either
008 * version 2.1 of the License, or (at your option) any later version.
009 *
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
013 * Lesser General Public License for more details.
014 *
015 * You should have received a copy of the GNU Lesser General Public
016 * License along with this library; if not, write to the Free Software
017 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
018 */
019
020 package jgb.builder;
021
022 import jgb.builder.utils.AttributesMapAdapter;
023 import jgb.factories.swing.PackageTagHandlerFactory;
024 import org.xml.sax.*;
025 import org.xml.sax.helpers.DefaultHandler;
026
027 import javax.swing.*;
028 import javax.xml.parsers.ParserConfigurationException;
029 import javax.xml.parsers.SAXParser;
030 import javax.xml.parsers.SAXParserFactory;
031 import java.io.IOException;
032 import java.io.InputStream;
033 import java.io.PrintWriter;
034 import java.util.*;
035 import java.util.List;
036 import java.awt.*;
037
038
039 /**
040 * The class that builds the windows and controls on behalf of the application.
041 * This class instantiates the necessary objects while reading the XML source
042 * file.
043 * @since 0.2a
044 * @author Francois Beausoleil, <a href="mailto:fbos@users.sourceforge.net">fbos@users.sourceforge.net</a>
045 */
046 public class DefaultBuilder extends DefaultHandler implements Builder {
047 private Map tagContext = new HashMap();
048 private boolean quiet = false;
049
050 private int level;
051 private boolean verbose = false;
052
053 private final List resolvers = new LinkedList();
054 private PrintWriter logStream = new PrintWriter(System.out);
055
056 /**
057 * Instantiate a <code>Builder</code> and use the default
058 * {@link jgb.builder.TagHandlerFactory TagHandlerFactory}.
059 * The default factory is {@link jgb.factories.swing.PackageTagHandlerFactory PackageTagHandlerFactory}.
060 */
061 public DefaultBuilder() {
062 this(new PackageTagHandlerFactory("jgb.handlers.swing", "TagHandler"));
063 }
064
065 /**
066 * Instantiate a <code>Builder</code> with the specified
067 * {@link jgb.builder.TagHandlerFactory TagHandlerFactory}.
068 * The <code>Builder</code> uses this factory to get all of it's tag handlers.
069 * All tags must implement {@link jgb.builder.TagHandler TagHandler}.
070 */
071 public DefaultBuilder(final TagHandlerFactory tagsFactory) {
072 Stack handlersFactoryStack = new Stack();
073 handlersFactoryStack.push(tagsFactory);
074 tagContext.put(TagHandler.TAG_HANDLER_FACTORY_STACK_KEY, handlersFactoryStack);
075 }
076
077 public void setQuiet(boolean quiet) {
078 this.quiet = quiet;
079 }
080
081 public Component build(InputStream in) throws IOException, SAXException {
082 if (null == in) {
083 throw new IllegalArgumentException("in must not be null");
084 }
085
086 return build(new InputSource(in));
087 }
088
089 public Component build(InputSource in) throws IOException, SAXException {
090 if (null == in) {
091 throw new IllegalArgumentException("InputSource cannot be be null");
092 } else if (null == in.getByteStream()
093 && null == in.getCharacterStream()
094 && null == in.getSystemId()
095 && null == in.getPublicId()) {
096 throw new IllegalArgumentException("InputSource should have at least one non-null source");
097 }
098
099 SAXParserFactory factory = SAXParserFactory.newInstance();
100 factory.setValidating(true);
101 SAXParser parser = null;
102 try {
103 parser = factory.newSAXParser();
104 } catch (ParserConfigurationException e) {
105 throw new SAXException("No validating parser present on this system", e);
106 }
107
108 tagContext.put(TagHandler.WINDOW_CONTEXT_KEY, this);
109 tagContext.put(TagHandler.OBJECTS_MAP_KEY, new HashMap());
110 parser.parse(in, this);
111 return (JWindow)tagContext.get(TagHandler.CURRENT_WINDOW_KEY);
112 }
113
114 public void setLoggingStream(PrintWriter logStream) {
115 this.logStream = logStream;
116 }
117
118 public Object getObject(String name) {
119 return (((Map)tagContext.get(TagHandler.OBJECTS_MAP_KEY)).get(name));
120 }
121
122 /**
123 * Initiates processing of the given element.
124 * This method will use the factory to get a {@link jgb.builder.TagHandler TagHandler}
125 * to process this tag.<br />
126 * Tag specific operations may occur during this method call.
127 */
128 public void startElement(java.lang.String namespaceURI,
129 java.lang.String localName,
130 java.lang.String qName,
131 Attributes atts) throws SAXException {
132 if (verbose) {
133 logStream.print(levelAsSpaces() + "<" + qName);
134 if (null != atts.getValue("id")) {
135 logStream.println(" id='" + atts.getValue("id") + "'>");
136 } else {
137 logStream.println(">");
138 }
139 logStream.flush();
140 }
141
142 TagHandler handler = getHandlerFor(qName);
143 handler.startElement(qName, tagContext, new AttributesMapAdapter(atts));
144
145 level++;
146 }
147
148 /**
149 * Terminates processing of the given element.
150 * This method will use the factory to get a {@link jgb.builder.TagHandler TagHandler}
151 * to process this tag.<br />
152 * Tag specific operations may occur during this method call.
153 */
154 public void endElement(String namespaceURI, String localName, String qName) throws SAXException {
155 level--;
156 if (level < 0) {
157 level = 0;
158 }
159
160 if (verbose) {
161 logStream.println(levelAsSpaces() + "</" + qName + ">");
162 logStream.flush();
163 }
164
165 TagHandler handler = getHandlerFor(qName);
166 handler.endElement(qName, tagContext);
167 }
168
169 /**
170 * Displays a warning message on the console, or no-op if in quiet mode.
171 */
172 public void warning(SAXParseException e) throws SAXException {
173 if (!quiet) {
174 logStream.print("WARNING: line: ");
175 logStream.print(e.getLineNumber());
176 logStream.print(", column: ");
177 logStream.print(e.getColumnNumber());
178 logStream.println(" - ");
179 logStream.print(e.getMessage());
180 logStream.print("(\"");
181 logStream.print(e.getPublicId());
182 logStream.print("\" \"");
183 logStream.print(e.getSystemId());
184 logStream.print("\")");
185 logStream.flush();
186 }
187 }
188
189 /**
190 * Displays a fatal error message on the console, or no-op if in quiet mode.
191 * In all cases, it throws a <code>SAXException<code> to signify that processing
192 * should stop.
193 */
194 public void fatalError(SAXParseException e) throws SAXException {
195 if (!quiet) {
196 logStream.print("FATAL: line: ");
197 logStream.print(e.getLineNumber());
198 logStream.print(", column: ");
199 logStream.print(e.getColumnNumber());
200 logStream.println(" - ");
201 logStream.print(e.getMessage());
202 logStream.print("(\"");
203 logStream.print(e.getPublicId());
204 logStream.print("\" \"");
205 logStream.print(e.getSystemId());
206 logStream.print("\")");
207 logStream.flush();
208 }
209
210 throw new SAXException("Fatal Error during parse", e);
211 }
212
213 /**
214 * Displays an error message on the console, or no-op if in quiet mode.
215 * In all cases, it throws a <code>SAXException</code> to signify that processing
216 * should stop.
217 */
218 public void error(SAXParseException e) throws SAXException {
219 if (!quiet) {
220 logStream.print("ERROR: line: ");
221 logStream.print(e.getLineNumber());
222 logStream.print(", column: ");
223 logStream.print(e.getColumnNumber());
224 logStream.println(" - ");
225 logStream.print(e.getMessage());
226 logStream.print("(\"");
227 logStream.print(e.getPublicId());
228 logStream.print("\" \"");
229 logStream.print(e.getSystemId());
230 logStream.print("\")");
231 logStream.flush();
232 }
233
234 throw new SAXException("Error during parse", e);
235 }
236
237 /**
238 * Saves the document locator that the parser might provide. If it does so,
239 * we are in business, else, we're toast...
240 */
241 public void setDocumentLocator(Locator locator) {
242 tagContext.put(TagHandler.DOCUMENT_LOCATOR_KEY, locator);
243 super.setDocumentLocator(locator);
244 }
245
246 public void setVerbose(boolean b) {
247 verbose = b;
248 }
249
250 /**
251 * Returns the {@link jgb.builder.TagHandler TagHandler} associated
252 * with the named tag.
253 * This method uses the {@link jgb.builder.TagHandlerFactory TagHandlerFactory} that
254 * was passed-in during instantiation to get the proper tag.
255 * @throws SAXException If a handler for the named tag cannot be found.
256 */
257 private TagHandler getHandlerFor(String qName) throws SAXException {
258 Stack handlersFactory = (Stack)tagContext.get(TagHandler.TAG_HANDLER_FACTORY_STACK_KEY);
259 if (handlersFactory.isEmpty()) {
260 EmptyStackException e = new EmptyStackException();
261 throw new SAXException("stack empty while processing <" + qName + ">", e);
262 }
263
264 TagHandlerFactory factory = (TagHandlerFactory)handlersFactory.peek();
265 try {
266 return factory.getHandlerFor(qName);
267 } catch (Exception e) {
268 throw new SAXException("Could not instantiate TagHandler for tag " + qName + ".", e);
269 }
270 }
271
272 private String levelAsSpaces() {
273 StringBuffer buf = new StringBuffer();
274 for (int i = 0; i < level; i++) {
275 buf.append(" ");
276 }
277
278 return buf.toString();
279 }
280
281 public void addResolver(EntityResolver resolver) {
282 resolvers.add(resolver);
283 }
284
285 public InputSource resolveEntity(String publicId, String systemId) throws SAXException {
286 try {
287 for (Iterator iterator = resolvers.iterator(); iterator.hasNext();) {
288 EntityResolver resolver = (EntityResolver)iterator.next();
289 InputSource entity = resolver.resolveEntity(publicId, systemId);
290 if (null != entity) {
291 return entity;
292 }
293 }
294
295 return super.resolveEntity(publicId, systemId);
296 } catch (IOException e) {
297 throw new SAXException(
298 "Unable to resolve '" + publicId + "' " +
299 "('" + systemId + "')", e);
300 }
301 }
302 }