FilterCodeHighlight


1   /**
2    * Copyright (C) 2001 Yasna.com. All rights reserved.
3    *
4    * ===================================================================
5    * The Apache Software License, Version 1.1
6    *
7    * Redistribution and use in source and binary forms, with or without
8    * modification, are permitted provided that the following conditions
9    * are met:
10   *
11   * 1. Redistributions of source code must retain the above copyright
12   *    notice, this list of conditions and the following disclaimer.
13   *
14   * 2. Redistributions in binary form must reproduce the above copyright
15   *    notice, this list of conditions and the following disclaimer in
16   *    the documentation and/or other materials provided with the
17   *    distribution.
18   *
19   * 3. The end-user documentation included with the redistribution,
20   *    if any, must include the following acknowledgment:
21   *       "This product includes software developed by
22   *        Yasna.com (http://www.yasna.com)."
23   *    Alternately, this acknowledgment may appear in the software itself,
24   *    if and wherever such third-party acknowledgments normally appear.
25   *
26   * 4. The names "Yazd" and "Yasna.com" must not be used to
27   *    endorse or promote products derived from this software without
28   *    prior written permission. For written permission, please
29   *    contact yazd@yasna.com.
30   *
31   * 5. Products derived from this software may not be called "Yazd",
32   *    nor may "Yazd" appear in their name, without prior written
33   *    permission of Yasna.com.
34   *
35   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
36   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38   * DISCLAIMED.  IN NO EVENT SHALL YASNA.COM OR
39   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46   * SUCH DAMAGE.
47   * ====================================================================
48   *
49   * This software consists of voluntary contributions made by many
50   * individuals on behalf of Yasna.com. For more information
51   * on Yasna.com, please see <http://www.yasna.com>.
52   */
53  
54  /**
55   * Copyright (C) 2000 CoolServlets.com. All rights reserved.
56   *
57   * ===================================================================
58   * The Apache Software License, Version 1.1
59   *
60   * Redistribution and use in source and binary forms, with or without
61   * modification, are permitted provided that the following conditions
62   * are met:
63   *
64   * 1. Redistributions of source code must retain the above copyright
65   *    notice, this list of conditions and the following disclaimer.
66   *
67   * 2. Redistributions in binary form must reproduce the above copyright
68   *    notice, this list of conditions and the following disclaimer in
69   *    the documentation and/or other materials provided with the
70   *    distribution.
71   *
72   * 3. The end-user documentation included with the redistribution,
73   *    if any, must include the following acknowledgment:
74   *       "This product includes software developed by
75   *        CoolServlets.com (http://www.coolservlets.com)."
76   *    Alternately, this acknowledgment may appear in the software itself,
77   *    if and wherever such third-party acknowledgments normally appear.
78   *
79   * 4. The names "Jive" and "CoolServlets.com" must not be used to
80   *    endorse or promote products derived from this software without
81   *    prior written permission. For written permission, please
82   *    contact webmaster@coolservlets.com.
83   *
84   * 5. Products derived from this software may not be called "Jive",
85   *    nor may "Jive" appear in their name, without prior written
86   *    permission of CoolServlets.com.
87   *
88   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
89   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
90   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
91   * DISCLAIMED.  IN NO EVENT SHALL COOLSERVLETS.COM OR
92   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
93   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
94   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
95   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
96   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
97   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
98   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99   * SUCH DAMAGE.
100  * ====================================================================
101  *
102  * This software consists of voluntary contributions made by many
103  * individuals on behalf of CoolServlets.com. For more information
104  * on CoolServlets.com, please see <http://www.coolservlets.com>.
105  */
106 
107 package com.Yasna.forum.filter;
108 
109 import java.io.*;
110 import java.util.*;
111 import com.Yasna.forum.*;
112 import com.Yasna.codeviewer.*;
113 
114 /**
115  * A ForumMessageFilter that syntax highlights Java code appearing between
116  * [code][/code] tags in the body of ForumMessage.
117  */
118 public class FilterCodeHighlight extends ForumMessageFilter
119         implements Serializable
120 {
121 
122     private static final String   NEW_LINE = System.getProperty("line.separator");
123 
124     /**
125      * Property values of the filter.
126      */
127     private Properties props;
128 
129     /**
130      * Property descriptions of the filter.
131      */
132     private Properties propDescriptions;
133 
134     /**
135      * Much of the work of this filter is done by a CodeViewer object. We
136      * make it a transient variable since there is no reason to serialize it.
137      */
138     private transient CodeViewer cv;
139 
140     /**
141      * Creates a new filter not associated with a message. This is
142      * generally only useful for defining a template filter that other
143      * fitlers will be cloned from.
144      */
145     public FilterCodeHighlight() {
146         super();
147         props = new Properties();
148         propDescriptions = new Properties();
149         cv = new CodeViewer();
150         initializeProperties();
151     }
152 
153     /**
154      * Creates a new filter wrapped around the specified message. This
155      * constructor is normally called when cloning a filter template.
156      *
157      * @param message the ForumMessage to wrap the new filter around.
158      * @param properties the property values for the filter.
159      * @param propertyDescriptions the property descriptions for the filter.
160      */
161     public FilterCodeHighlight(ForumMessage message, Properties properties,
162             Properties propertyDescriptions)
163     {
164         super(message);
165         this.props = new Properties(properties);
166         this.propDescriptions = new Properties(propertyDescriptions);
167         cv = new CodeViewer();
168         applyProperties();
169     }
170 
171     /**
172      * Clones a new filter that will have the same properties and that
173      * will wrap around the specified message.
174      *
175      * @param message the ForumMessage to wrap the new filter around.
176      */
177     public ForumMessageFilter clone(ForumMessage message){
178         return new FilterCodeHighlight(message, props, propDescriptions);
179     }
180 
181     /**
182      * Returns the name of the filter.
183      */
184     public String   getName() {
185         return "Java Code Syntax Highlighter";
186     }
187 
188     /**
189      * Returns a description of the filter.
190      */
191     public String   getDescription() {
192         return "Highlights Java code that appears between [code][/code] tags";
193     }
194 
195     /**
196      * Returns the author of the filter.
197      */
198     public String   getAuthor() {
199         return "CoolServlets.com";
200     }
201 
202     /**
203      * Returns the major version number of the filter.
204      */
205     public int getMajorVersion() {
206         return 1;
207     }
208 
209     /**
210      * Returns the minor version number of the filter.
211      */
212     public int getMinorVersion() {
213         return 0;
214     }
215 
216     /**
217      * Returns the value of a property of the filter.
218      *
219      * @param name the name of the property.
220      * @returns the value of the property.
221      */
222     public String   getFilterProperty(String   name) {
223         return props.getProperty(name);
224     }
225 
226     /**
227      * Returns the description of a property of the filter.
228      *
229      * @param name the name of the property.
230      * @return the description of the property.
231      */
232     public String   getFilterPropertyDescription(String   name) {
233         return propDescriptions.getProperty(name);
234     }
235 
236     /**
237      * Returns an Enumeration of all the property names.
238      */
239     public Enumeration filterPropertyNames() {
240         return props.propertyNames();
241     }
242 
243     /**
244      * Sets a property of the filter. Each filter has a set number of
245      * properties that are determined by the filter author. 
246      *
247      * @param name the name of the property to set.
248      * @param value the new value for the property.
249      *
250      * @throws IllegalArgumentException if the property trying to be set doesn't
251      *    exist.
252      */
253     public void setFilterProperty(String   name, String   value)
254             throws IllegalArgumentException  
255     {
256         if (props.getProperty(name) == null) {
257             throw new IllegalArgumentException  ();
258         }
259         props.put(name, value);
260         applyProperties();
261     }
262 
263     /**
264      * <b>Overloaded</b> to return the body of message with Java code between
265      * [code] [/code] tags syntax highlighted.
266      */
267     public String   getBody() {
268         return highlightCode(message.getBody());
269     }
270 
271     /**
272      * Creates properties and sets their descriptions.
273      */
274     private void initializeProperties() {
275         props.put("commentStart",cv.getCommentStart());
276         props.put("commentEnd",cv.getCommentEnd());
277         props.put("stringStart",cv.getStringStart());
278         props.put("stringEnd",cv.getStringEnd());
279         props.put("reservedWordStart",cv.getReservedWordStart());
280         props.put("reservedWordEnd",cv.getReservedWordEnd());
281 
282         propDescriptions.put("commentStart","A HTML start tag that determines how comments will be displayed");
283         propDescriptions.put("commentEnd","A HTML end tag that should correspond to the commentStart tag");
284         propDescriptions.put("stringStart","A HTML start tag that determines how strings will be displayed");
285         propDescriptions.put("stringEnd","A HTML end tag that should correspond to the stringStart tag");
286         propDescriptions.put("reservedWordStart","A HTML start tag that determines how reserved words will be displayed");
287         propDescriptions.put("reservedWordEnd","A HTML end tag that should correspond to the reservedWordStart tag");
288     }
289 
290     private void applyProperties() {
291         cv.setCommentStart(props.getProperty("commentStart"));
292         cv.setCommentEnd(props.getProperty("commentEnd"));
293         cv.setStringStart(props.getProperty("stringStart"));
294         cv.setStringEnd(props.getProperty("stringEnd"));
295         cv.setReservedWordStart(props.getProperty("reservedWordStart"));
296         cv.setReservedWordEnd(props.getProperty("reservedWordEnd"));
297     }
298 
299     /**
300     * This method takes a string which may contain Java code.
301     * The Java code will be highlighted.
302     *
303     * @param input The text to be converted.
304     * @return The input string with any Java code highlighted.
305     */
306     private String   highlightCode( String   input ) {
307         // Check if the string is null or zero length -- if so, return what was sent in.
308         if( input == null || input.length() == 0 ) {
309             return input;
310         }
311         else {
312             StringBuffer   buf = new StringBuffer  ();
313             int i = 0, j = 0, oldend = 0;
314 
315             while ( ( i=input.indexOf( "[code]", oldend ) ) >= 0 ) {
316                 //Check to see where the ending code tag is and store than in j
317                 if ( (j=input.indexOf( "[/code]", i+6 ) ) < 0)  {
318                     //End at end of input if no closing tag is given
319                     j = input.length()-7;
320                 }
321                 // Take the string up to the code, append the string returned by CodeViewer
322                 buf.append(input.substring(oldend,i));
323                 buf.append("<pre>");
324                 //Read line by line and filter accordingly.
325                 //StringTokenizer tokens = new StringTokenizer(input.substring(i+6,j-1), NEW_LINE);
326                 StringTokenizer tokens = new StringTokenizer(input.substring(i+6,j), NEW_LINE);
327                 while (tokens.hasMoreTokens()) {
328                     buf.append(cv.syntaxHighlight(tokens.nextToken()));
329                     buf.append(NEW_LINE);
330                 }
331                 buf.append("</pre>");
332                 // Next time, want to start looking after ending [/code] tag
333                 oldend = j+7;
334             }
335             buf.append(input.substring(oldend,input.length()));
336             return buf.toString();
337         }
338     }
339 }
340
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