001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 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 if statements.
028 *
029 */
030public class IfHandler extends BlockParentHandler {
031
032    /**
033     * Construct an instance of this handler with the given indentation context,
034     * abstract syntax tree, and parent handler.
035     *
036     * @param context        the indentation check
037     * @param ast           the abstract syntax tree
038     * @param parent        the parent handler
039     */
040    public IfHandler(IndentationContext context,
041        DetailAST ast, AbstractExpressionHandler parent) {
042        super(context, "if", ast, parent);
043    }
044
045    @Override
046    public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
047        final IndentLevel result;
048        if (child instanceof ElseHandler) {
049            result = getIndent();
050        }
051        else {
052            result = super.getSuggestedChildIndent(child);
053        }
054        return result;
055    }
056
057    @Override
058    protected IndentLevel getIndentImpl() {
059        final IndentLevel result;
060        if (isIfAfterElse()) {
061            result = getParent().getIndent();
062        }
063        else {
064            result = super.getIndentImpl();
065        }
066        return result;
067    }
068
069    /**
070     * Determines if this 'if' statement is part of an 'else' clause and on the same line.
071     *
072     * @return true if this 'if' is part of an 'else', false otherwise
073     */
074    private boolean isIfAfterElse() {
075        // check if there is an 'else' and an 'if' on the same line
076        final DetailAST parent = getMainAst().getParent();
077        return parent.getType() == TokenTypes.LITERAL_ELSE
078            && TokenUtil.areOnSameLine(parent, getMainAst());
079    }
080
081    @Override
082    protected void checkTopLevelToken() {
083        if (!isIfAfterElse()) {
084            super.checkTopLevelToken();
085        }
086    }
087
088    /**
089     * Check the indentation of the conditional expression.
090     */
091    private void checkCondExpr() {
092        final DetailAST condAst = getMainAst().findFirstToken(TokenTypes.LPAREN)
093            .getNextSibling();
094        final IndentLevel expected =
095            new IndentLevel(getIndent(), getBasicOffset());
096        checkExpressionSubtree(condAst, expected, false, false);
097    }
098
099    @Override
100    public void checkIndentation() {
101        super.checkIndentation();
102        checkCondExpr();
103        checkWrappingIndentation(getMainAst(), getIfStatementRightParen(getMainAst()));
104    }
105
106    /**
107     * Returns right parenthesis of if statement.
108     *
109     * @param literalIfAst
110     *          literal-if ast node(TokenTypes.LITERAL_IF)
111     * @return right parenthesis of if statement.
112     */
113    private static DetailAST getIfStatementRightParen(DetailAST literalIfAst) {
114        return literalIfAst.findFirstToken(TokenTypes.RPAREN);
115    }
116
117}