View Javadoc
1   ///////////////////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3   // Copyright (C) 2001-2025 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.indentation;
21  
22  import com.puppycrawl.tools.checkstyle.api.DetailAST;
23  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
25  
26  /**
27   * Handler for case statements.
28   *
29   */
30  public class CaseHandler extends AbstractExpressionHandler {
31  
32      /**
33       * The child elements of a case expression.
34       */
35      private static final int[] CASE_CHILDREN = {
36          TokenTypes.LITERAL_CASE,
37          TokenTypes.LITERAL_DEFAULT,
38      };
39  
40      /**
41       * Construct an instance of this handler with the given indentation check,
42       * abstract syntax tree, and parent handler.
43       *
44       * @param indentCheck   the indentation check
45       * @param expr          the abstract syntax tree
46       * @param parent        the parent handler
47       */
48      public CaseHandler(IndentationCheck indentCheck,
49          DetailAST expr, AbstractExpressionHandler parent) {
50          super(indentCheck, "case", expr, parent);
51      }
52  
53      @Override
54      protected IndentLevel getIndentImpl() {
55          return new IndentLevel(getParent().getIndent(),
56                                 getIndentCheck().getCaseIndent());
57      }
58  
59      /**
60       * Check the indentation of the case statement.
61       */
62      private void checkCase() {
63          // only need to check if the case statement is not on the same line as
64          // the parent switch statement
65          if (!isSameLineAsSwitch()) {
66              checkChildren(getMainAst(), CASE_CHILDREN, getIndent(), true, false);
67          }
68      }
69  
70      @Override
71      public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
72          return getIndent();
73      }
74  
75      @Override
76      public void checkIndentation() {
77          checkCase();
78      }
79  
80      /**
81       * Checks if CASE_GROUP node is placed at the same line as SWITCH_LITERAL node.
82       *
83       * @return true, if CASE_GROUP node is places at the same line as SWITCH_LITERAL node.
84       */
85      private boolean isSameLineAsSwitch() {
86          final DetailAST parentNode = getMainAst().getParent();
87          return TokenUtil.areOnSameLine(getMainAst(), parentNode);
88      }
89  
90  }