KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > edu > rice > cs > drjava > model > definitions > indent > QuestionStartingNewStmt


1 /*BEGIN_COPYRIGHT_BLOCK
2  *
3  * This file is part of DrJava. Download the current version of this project from http://www.drjava.org/
4  * or http://sourceforge.net/projects/drjava/
5  *
6  * DrJava Open Source License
7  *
8  * Copyright (C) 2001-2006 JavaPLT group at Rice University (javaplt@rice.edu). All rights reserved.
9  *
10  * Developed by: Java Programming Languages Team, Rice University, http://www.cs.rice.edu/~javaplt/
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
13  * documentation files (the "Software"), to deal with the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and
15  * to permit persons to whom the Software is furnished to do so, subject to the following conditions:
16  *
17  * - Redistributions of source code must retain the above copyright notice, this list of conditions and the
18  * following disclaimers.
19  * - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
20  * following disclaimers in the documentation and/or other materials provided with the distribution.
21  * - Neither the names of DrJava, the JavaPLT, Rice University, nor the names of its contributors may be used to
22  * endorse or promote products derived from this Software without specific prior written permission.
23  * - Products derived from this software may not be called "DrJava" nor use the term "DrJava" as part of their
24  * names without prior written permission from the JavaPLT group. For permission, write to javaplt@rice.edu.
25  *
26  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
27  * THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28  * CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
29  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
30  * WITH THE SOFTWARE.
31  *
32  *END_COPYRIGHT_BLOCK*/
33
34 package edu.rice.cs.drjava.model.definitions.indent;
35
36 import javax.swing.text.BadLocationException JavaDoc;
37
38 import edu.rice.cs.util.UnexpectedException;
39 import edu.rice.cs.drjava.model.AbstractDJDocument;
40
41 /**
42  * Determines if the current line is starting a new statement by
43  * searching backwards to see if the previous line was the end
44  * of a statement. Specifically, checks if the previous
45  * non-whitespace character not on this line is one of the
46  * following: ';', '{', '}', or DOCSTART.
47  * <p>
48  * Note that characters in comments and quotes are disregarded.
49  *
50  * @version $Id: QuestionStartingNewStmt.java 3901 2006-06-30 05:28:11Z rcartwright $
51  */
52 public class QuestionStartingNewStmt extends IndentRuleQuestion {
53   
54   /**
55    * Constructs a new rule to determine if the current line is
56    * the start of a new statement.
57    * @param yesRule Rule to use if this rule holds
58    * @param noRule Rule to use if this rule does not hold
59    */
60   public QuestionStartingNewStmt(IndentRule yesRule, IndentRule noRule) {
61     super(yesRule, noRule);
62   }
63  
64   /**
65    * Determines if the previous non-whitespace character not on
66    * this line was one of the following: ';', '{', '}' or DOCSTART.
67    * Ignores characters in quotes and comments.
68    * @param doc AbstractDJDocument containing the line to be indented.
69    * @return true if this node's rule holds.
70    */
71   boolean applyRule(AbstractDJDocument doc, int reason) {
72     
73     char[] delims = {';', '{', '}'};
74     int lineStart = doc.getLineStartPos(doc.getCurrentLocation());
75     int prevDelimiterPos;
76     
77     try {
78       prevDelimiterPos = doc.findPrevDelimiter(lineStart, delims);
79     } catch (BadLocationException JavaDoc e) {
80       // Should not happen
81 throw new UnexpectedException(e);
82     }
83     
84     // For DOCSTART, imaginary delimiter at position -1
85 if (prevDelimiterPos == AbstractDJDocument.ERROR_INDEX) {
86       prevDelimiterPos = -1;
87     }
88     
89     // Delimiter must be at the end of its line (ignoring whitespace & comments)
90 int firstNonWSAfterDelimiter;
91     try {
92       firstNonWSAfterDelimiter = doc.getFirstNonWSCharPos(prevDelimiterPos+1);
93       // will return ERROR_INDEX if we hit the end of the document
94 } catch (BadLocationException JavaDoc e) {
95       throw new UnexpectedException(e);
96     }
97     
98     // If the first non-WS character is after the beginning of the line
99 // or we reached the end of the document, then we are starting a new statement.
100 return (firstNonWSAfterDelimiter >= lineStart
101               || firstNonWSAfterDelimiter == AbstractDJDocument.ERROR_INDEX);
102   }
103 }
104
105
Popular Tags