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.whitespace;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024import com.puppycrawl.tools.checkstyle.checks.AbstractOptionCheck;
025import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
026
027/**
028 * <p>Checks the padding of an empty for initializer; that is whether a
029 * space is required at an empty for initializer, or such spaces are
030 * forbidden. No check occurs if there is a line wrap at the initializer, as in
031 * </p>
032 * <pre class="body">
033for (
034      ; i &lt; j; i++, j--)
035   </pre>
036 * <p>
037 * The policy to verify is specified using the {@link PadOption} class and
038 * defaults to {@link PadOption#NOSPACE}.
039 * </p>
040 * <p>
041 * An example of how to configure the check is:
042 * </p>
043 * <pre>
044 * &lt;module name="EmptyForInitializerPad"/&gt;
045 * </pre>
046 *
047 * @author lkuehne
048 */
049public class EmptyForInitializerPadCheck
050    extends AbstractOptionCheck<PadOption> {
051
052    /**
053     * A key is pointing to the warning message text in "messages.properties"
054     * file.
055     */
056    public static final String MSG_PRECEDED = "ws.preceded";
057
058    /**
059     * A key is pointing to the warning message text in "messages.properties"
060     * file.
061     */
062    public static final String MSG_NOT_PRECEDED = "ws.notPreceded";
063
064    /**
065     * Sets the paren pad option to nospace.
066     */
067    public EmptyForInitializerPadCheck() {
068        super(PadOption.NOSPACE, PadOption.class);
069    }
070
071    @Override
072    public int[] getDefaultTokens() {
073        return getAcceptableTokens();
074    }
075
076    @Override
077    public int[] getAcceptableTokens() {
078        return new int[] {TokenTypes.FOR_INIT};
079    }
080
081    @Override
082    public int[] getRequiredTokens() {
083        return getAcceptableTokens();
084    }
085
086    @Override
087    public void visitToken(DetailAST ast) {
088        if (ast.getChildCount() == 0) {
089            //empty for initializer. test pad before semi.
090            final DetailAST semi = ast.getNextSibling();
091            final int semiLineIdx = semi.getLineNo() - 1;
092            final String line = getLines()[semiLineIdx];
093            final int before = semi.getColumnNo() - 1;
094            //don't check if semi at beginning of line
095            if (!CommonUtils.hasWhitespaceBefore(before, line)) {
096                final PadOption option = getAbstractOption();
097                if (option == PadOption.NOSPACE
098                    && Character.isWhitespace(line.charAt(before))) {
099                    log(semi.getLineNo(), before, MSG_PRECEDED, SEMICOLON);
100                }
101                else if (option == PadOption.SPACE
102                         && !Character.isWhitespace(line.charAt(before))) {
103                    log(semi.getLineNo(), before, MSG_NOT_PRECEDED, SEMICOLON);
104                }
105            }
106        }
107    }
108}