001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2018 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.coding;
021
022import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
023import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
024import com.puppycrawl.tools.checkstyle.api.DetailAST;
025import com.puppycrawl.tools.checkstyle.api.TokenTypes;
026import com.puppycrawl.tools.checkstyle.utils.CheckUtils;
027
028/**
029 * Restricts nested if-else blocks to a specified depth (default = 1).
030 *
031 */
032@FileStatefulCheck
033public final class NestedIfDepthCheck extends AbstractCheck {
034
035    /**
036     * A key is pointing to the warning message text in "messages.properties"
037     * file.
038     */
039    public static final String MSG_KEY = "nested.if.depth";
040
041    /** Maximum allowed nesting depth. */
042    private int max = 1;
043    /** Current nesting depth. */
044    private int depth;
045
046    /**
047     * Setter for maximum allowed nesting depth.
048     * @param max maximum allowed nesting depth.
049     */
050    public void setMax(int max) {
051        this.max = max;
052    }
053
054    @Override
055    public int[] getDefaultTokens() {
056        return getRequiredTokens();
057    }
058
059    @Override
060    public int[] getAcceptableTokens() {
061        return getRequiredTokens();
062    }
063
064    @Override
065    public int[] getRequiredTokens() {
066        return new int[] {TokenTypes.LITERAL_IF};
067    }
068
069    @Override
070    public void beginTree(DetailAST rootAST) {
071        depth = 0;
072    }
073
074    @Override
075    public void visitToken(DetailAST literalIf) {
076        if (!CheckUtils.isElseIf(literalIf)) {
077            if (depth > max) {
078                log(literalIf, MSG_KEY, depth, max);
079            }
080            ++depth;
081        }
082    }
083
084    @Override
085    public void leaveToken(DetailAST literalIf) {
086        if (!CheckUtils.isElseIf(literalIf)) {
087            --depth;
088        }
089    }
090
091}