001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2015 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;
024
025/**
026 * Handler for if statements.
027 *
028 * @author jrichard
029 */
030public class IfHandler extends BlockParentHandler {
031    /**
032     * Construct an instance of this handler with the given indentation check,
033     * abstract syntax tree, and parent handler.
034     *
035     * @param indentCheck   the indentation check
036     * @param ast           the abstract syntax tree
037     * @param parent        the parent handler
038     */
039    public IfHandler(IndentationCheck indentCheck,
040        DetailAST ast, AbstractExpressionHandler parent) {
041        super(indentCheck, "if", ast, parent);
042    }
043
044    @Override
045    public IndentLevel suggestedChildLevel(AbstractExpressionHandler child) {
046        if (child instanceof ElseHandler) {
047            return getLevel();
048        }
049        return super.suggestedChildLevel(child);
050    }
051
052    @Override
053    protected IndentLevel getLevelImpl() {
054        if (isIfAfterElse()) {
055            return getParent().getLevel();
056        }
057        return super.getLevelImpl();
058    }
059
060    /**
061     * Determines if this 'if' statement is part of an 'else' clause
062     * and on the same line.
063     *
064     * @return true if this 'if' is part of an 'else', false otherwise
065     */
066    private boolean isIfAfterElse() {
067        // check if there is an 'else' and an 'if' on the same line
068        final DetailAST parent = getMainAst().getParent();
069        return parent.getType() == TokenTypes.LITERAL_ELSE
070            && parent.getLineNo() == getMainAst().getLineNo();
071    }
072
073    @Override
074    protected void checkTopLevelToken() {
075        if (isIfAfterElse()) {
076            return;
077        }
078
079        super.checkTopLevelToken();
080    }
081
082    /**
083     * Check the indentation of the conditional expression.
084     */
085    private void checkCondExpr() {
086        final DetailAST condAst = getMainAst().findFirstToken(TokenTypes.LPAREN)
087            .getNextSibling();
088        final IndentLevel expected =
089            new IndentLevel(getLevel(), getBasicOffset());
090        checkExpressionSubtree(condAst, expected, false, false);
091    }
092
093    @Override
094    public void checkIndentation() {
095        super.checkIndentation();
096        checkCondExpr();
097        final LineWrappingHandler lineWrap =
098            new LineWrappingHandler(getIndentCheck(), getMainAst(),
099                    getIfStatementRightParen(getMainAst()));
100        lineWrap.checkIndentation();
101    }
102
103    /**
104     * Returns right parenthesis of if statement.
105     * @param literalIfAst
106     *          literal-if ast node(TokenTypes.LITERAL_IF)
107     * @return right parenthesis of if statement.
108     */
109    private static DetailAST getIfStatementRightParen(DetailAST literalIfAst) {
110        return literalIfAst.findFirstToken(TokenTypes.RPAREN);
111    }
112}