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 switch rules.
28 */
29 public class SwitchRuleHandler extends AbstractExpressionHandler {
30
31 /**
32 * The child elements of a switch rule.
33 */
34 private static final int[] SWITCH_RULE_CHILDREN = {
35 TokenTypes.LITERAL_CASE,
36 TokenTypes.LITERAL_DEFAULT,
37 };
38
39 /**
40 * Construct an instance of this handler with the given indentation check,
41 * abstract syntax tree, and parent handler.
42 *
43 * @param indentCheck the indentation check
44 * @param expr the abstract syntax tree
45 * @param parent the parent handler
46 */
47 public SwitchRuleHandler(IndentationCheck indentCheck,
48 DetailAST expr, AbstractExpressionHandler parent) {
49 super(indentCheck, "case", expr, parent);
50 }
51
52 @Override
53 protected IndentLevel getIndentImpl() {
54 return new IndentLevel(getParent().getIndent(),
55 getIndentCheck().getCaseIndent());
56 }
57
58 /**
59 * Check the indentation of the case statement.
60 */
61 private void checkCase() {
62 // only need to check if the case statement is not on the same line as
63 // the parent switch statement
64 if (!isSameLineAsSwitch()) {
65 checkChildren(getMainAst(), SWITCH_RULE_CHILDREN, getIndent(),
66 true, false);
67 }
68 }
69
70 @Override
71 public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
72 final IndentLevel result;
73
74 if (child instanceof SlistHandler) {
75 // switchRule with block body (enclosed in {})
76 result = getIndent();
77 }
78 else {
79 // Single-expression switchRule (no {} block):
80 // assume line wrapping and add additional indentation
81 // for the statement in the next line.
82 result = new IndentLevel(getIndent(), getIndentCheck().getLineWrappingIndentation());
83 }
84
85 return result;
86 }
87
88 @Override
89 public void checkIndentation() {
90 checkCase();
91 }
92
93 /**
94 * Checks if SWITCH_RULE node is placed at the same line as SWITCH_LITERAL node.
95 *
96 * @return true, if SWITCH_RULE node is places at the same line as SWITCH_LITERAL node.
97 */
98 private boolean isSameLineAsSwitch() {
99 final DetailAST parentNode = getMainAst().getParent();
100 return TokenUtil.areOnSameLine(getMainAst(), parentNode);
101 }
102
103 }