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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   * <div>
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   * </div>
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   *
49   * <p>
50   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
51   * </p>
52   *
53   * <p>
54   * Violation Message Keys:
55   * </p>
56   * <ul>
57   * <li>
58   * {@code ws.followed}
59   * </li>
60   * <li>
61   * {@code ws.notFollowed}
62   * </li>
63   * </ul>
64   *
65   * @since 3.0
66   */
67  @StatelessCheck
68  public class EmptyForIteratorPadCheck
69      extends AbstractCheck {
70  
71      /**
72       * A key is pointing to the warning message text in "messages.properties"
73       * file.
74       */
75      public static final String MSG_WS_FOLLOWED = "ws.followed";
76  
77      /**
78       * A key is pointing to the warning message text in "messages.properties"
79       * file.
80       */
81      public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed";
82  
83      /** Semicolon literal. */
84      private static final String SEMICOLON = ";";
85  
86      /** Specify policy on how to pad an empty for iterator. */
87      private PadOption option = PadOption.NOSPACE;
88  
89      /**
90       * Setter to specify policy on how to pad an empty for iterator.
91       *
92       * @param optionStr string to decode option from
93       * @throws IllegalArgumentException if unable to decode
94       * @since 3.0
95       */
96      public void setOption(String optionStr) {
97          option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
98      }
99  
100     @Override
101     public int[] getDefaultTokens() {
102         return getRequiredTokens();
103     }
104 
105     @Override
106     public int[] getAcceptableTokens() {
107         return getRequiredTokens();
108     }
109 
110     @Override
111     public int[] getRequiredTokens() {
112         return new int[] {TokenTypes.FOR_ITERATOR};
113     }
114 
115     @Override
116     public void visitToken(DetailAST ast) {
117         if (!ast.hasChildren()) {
118             // empty for iterator. test pad after semi.
119             final DetailAST semi = ast.getPreviousSibling();
120             final int[] line = getLineCodePoints(semi.getLineNo() - 1);
121             final int after = semi.getColumnNo() + 1;
122             // don't check if at end of line
123             if (after < line.length) {
124                 if (option == PadOption.NOSPACE
125                     && CommonUtil.isCodePointWhitespace(line, after)) {
126                     log(ast, MSG_WS_FOLLOWED, SEMICOLON);
127                 }
128                 else if (option == PadOption.SPACE
129                          && !CommonUtil.isCodePointWhitespace(line, after)) {
130                     log(ast, MSG_WS_NOT_FOLLOWED, SEMICOLON);
131                 }
132             }
133         }
134     }
135 
136 }