001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2025 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.indentation;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
025
026/**
027 * Handler for switch rules.
028 */
029public class SwitchRuleHandler extends AbstractExpressionHandler {
030
031    /**
032     * The child elements of a switch rule.
033     */
034    private static final int[] SWITCH_RULE_CHILDREN = {
035        TokenTypes.LITERAL_CASE,
036        TokenTypes.LITERAL_DEFAULT,
037    };
038
039    /**
040     * Construct an instance of this handler with the given indentation check,
041     * abstract syntax tree, and parent handler.
042     *
043     * @param indentCheck the indentation check
044     * @param expr        the abstract syntax tree
045     * @param parent      the parent handler
046     */
047    public SwitchRuleHandler(IndentationCheck indentCheck,
048                       DetailAST expr, AbstractExpressionHandler parent) {
049        super(indentCheck, "case", expr, parent);
050    }
051
052    @Override
053    protected IndentLevel getIndentImpl() {
054        return new IndentLevel(getParent().getIndent(),
055            getIndentCheck().getCaseIndent());
056    }
057
058    /**
059     * Check the indentation of the case statement.
060     */
061    private void checkCase() {
062        // only need to check if the case statement is not on the same line as
063        // the parent switch statement
064        if (!isSameLineAsSwitch()) {
065            checkChildren(getMainAst(), SWITCH_RULE_CHILDREN, getIndent(),
066                    true, false);
067        }
068    }
069
070    @Override
071    public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
072        final IndentLevel result;
073
074        if (child instanceof SlistHandler) {
075            // switchRule with block body (enclosed in {})
076            result = getIndent();
077        }
078        else {
079            // Single-expression switchRule (no {} block):
080            // assume line wrapping and add additional indentation
081            // for the statement in the next line.
082            result = new IndentLevel(getIndent(), getIndentCheck().getLineWrappingIndentation());
083        }
084
085        return result;
086    }
087
088    @Override
089    public void checkIndentation() {
090        checkCase();
091    }
092
093    /**
094     * Checks if SWITCH_RULE node is placed at the same line as SWITCH_LITERAL node.
095     *
096     * @return true, if SWITCH_RULE node is places at the same line as SWITCH_LITERAL node.
097     */
098    private boolean isSameLineAsSwitch() {
099        final DetailAST parentNode = getMainAst().getParent();
100        return TokenUtil.areOnSameLine(getMainAst(), parentNode);
101    }
102
103}