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 case statements.
028 *
029 */
030public class CaseHandler extends AbstractExpressionHandler {
031
032    /**
033     * The child elements of a case expression.
034     */
035    private static final int[] CASE_CHILDREN = {
036        TokenTypes.LITERAL_CASE,
037        TokenTypes.LITERAL_DEFAULT,
038    };
039
040    /**
041     * Construct an instance of this handler with the given indentation check,
042     * abstract syntax tree, and parent handler.
043     *
044     * @param indentCheck   the indentation check
045     * @param expr          the abstract syntax tree
046     * @param parent        the parent handler
047     */
048    public CaseHandler(IndentationCheck indentCheck,
049        DetailAST expr, AbstractExpressionHandler parent) {
050        super(indentCheck, "case", expr, parent);
051    }
052
053    @Override
054    protected IndentLevel getIndentImpl() {
055        return new IndentLevel(getParent().getIndent(),
056                               getIndentCheck().getCaseIndent());
057    }
058
059    /**
060     * Check the indentation of the case statement.
061     */
062    private void checkCase() {
063        // only need to check if the case statement is not on the same line as
064        // the parent switch statement
065        if (!isSameLineAsSwitch()) {
066            checkChildren(getMainAst(), CASE_CHILDREN, getIndent(), true, false);
067        }
068    }
069
070    @Override
071    public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
072        return getIndent();
073    }
074
075    @Override
076    public void checkIndentation() {
077        checkCase();
078    }
079
080    /**
081     * Checks if CASE_GROUP node is placed at the same line as SWITCH_LITERAL node.
082     *
083     * @return true, if CASE_GROUP node is places at the same line as SWITCH_LITERAL node.
084     */
085    private boolean isSameLineAsSwitch() {
086        final DetailAST parentNode = getMainAst().getParent();
087        return TokenUtil.areOnSameLine(getMainAst(), parentNode);
088    }
089
090}