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1   ///////////////////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3   // Copyright (C) 2001-2024 the original author or authors.
4   //
5   // This library is free software; you can redistribute it and/or
6   // modify it under the terms of the GNU Lesser General Public
7   // License as published by the Free Software Foundation; either
8   // version 2.1 of the License, or (at your option) any later version.
9   //
10  // This library is distributed in the hope that it will be useful,
11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  // Lesser General Public License for more details.
14  //
15  // You should have received a copy of the GNU Lesser General Public
16  // License along with this library; if not, write to the Free Software
17  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  ///////////////////////////////////////////////////////////////////////////////////////////////
19  
20  package com.puppycrawl.tools.checkstyle.checks.whitespace;
21  
22  import java.util.Locale;
23  
24  import com.puppycrawl.tools.checkstyle.StatelessCheck;
25  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
26  import com.puppycrawl.tools.checkstyle.api.DetailAST;
27  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
28  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
29  
30  /**
31   * <p>
32   * Checks the padding of an empty for iterator; that is whether a white
33   * space is required at an empty for iterator, or such white space is
34   * forbidden. No check occurs if there is a line wrap at the iterator, as in
35   * </p>
36   * <pre>
37   * for (Iterator foo = very.long.line.iterator();
38   *     foo.hasNext();
39   *    )
40   * </pre>
41   * <ul>
42   * <li>
43   * Property {@code option} - Specify policy on how to pad an empty for iterator.
44   * Type is {@code com.puppycrawl.tools.checkstyle.checks.whitespace.PadOption}.
45   * Default value is {@code nospace}.
46   * </li>
47   * </ul>
48   * <p>
49   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
50   * </p>
51   * <p>
52   * Violation Message Keys:
53   * </p>
54   * <ul>
55   * <li>
56   * {@code ws.followed}
57   * </li>
58   * <li>
59   * {@code ws.notFollowed}
60   * </li>
61   * </ul>
62   *
63   * @since 3.0
64   */
65  @StatelessCheck
66  public class EmptyForIteratorPadCheck
67      extends AbstractCheck {
68  
69      /**
70       * A key is pointing to the warning message text in "messages.properties"
71       * file.
72       */
73      public static final String MSG_WS_FOLLOWED = "ws.followed";
74  
75      /**
76       * A key is pointing to the warning message text in "messages.properties"
77       * file.
78       */
79      public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed";
80  
81      /** Semicolon literal. */
82      private static final String SEMICOLON = ";";
83  
84      /** Specify policy on how to pad an empty for iterator. */
85      private PadOption option = PadOption.NOSPACE;
86  
87      /**
88       * Setter to specify policy on how to pad an empty for iterator.
89       *
90       * @param optionStr string to decode option from
91       * @throws IllegalArgumentException if unable to decode
92       * @since 3.0
93       */
94      public void setOption(String optionStr) {
95          option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
96      }
97  
98      @Override
99      public int[] getDefaultTokens() {
100         return getRequiredTokens();
101     }
102 
103     @Override
104     public int[] getAcceptableTokens() {
105         return getRequiredTokens();
106     }
107 
108     @Override
109     public int[] getRequiredTokens() {
110         return new int[] {TokenTypes.FOR_ITERATOR};
111     }
112 
113     @Override
114     public void visitToken(DetailAST ast) {
115         if (!ast.hasChildren()) {
116             // empty for iterator. test pad after semi.
117             final DetailAST semi = ast.getPreviousSibling();
118             final int[] line = getLineCodePoints(semi.getLineNo() - 1);
119             final int after = semi.getColumnNo() + 1;
120             // don't check if at end of line
121             if (after < line.length) {
122                 if (option == PadOption.NOSPACE
123                     && CommonUtil.isCodePointWhitespace(line, after)) {
124                     log(ast, MSG_WS_FOLLOWED, SEMICOLON);
125                 }
126                 else if (option == PadOption.SPACE
127                          && !CommonUtil.isCodePointWhitespace(line, after)) {
128                     log(ast, MSG_WS_NOT_FOLLOWED, SEMICOLON);
129                 }
130             }
131         }
132     }
133 
134 }