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.whitespace;
021
022import java.util.Locale;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.TokenTypes;
028import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
029
030/**
031 * <p>Checks the padding of an empty for initializer; that is whether a
032 * space is required at an empty for initializer, or such spaces are
033 * forbidden. No check occurs if there is a line wrap at the initializer, as in
034 * </p>
035 * <pre class="body">
036for (
037      ; i &lt; j; i++, j--)
038   </pre>
039 * <p>
040 * The policy to verify is specified using the {@link PadOption} class and
041 * defaults to {@link PadOption#NOSPACE}.
042 * </p>
043 * <p>
044 * An example of how to configure the check is:
045 * </p>
046 * <pre>
047 * &lt;module name="EmptyForInitializerPad"/&gt;
048 * </pre>
049 *
050 */
051@StatelessCheck
052public class EmptyForInitializerPadCheck
053    extends AbstractCheck {
054
055    /**
056     * A key is pointing to the warning message text in "messages.properties"
057     * file.
058     */
059    public static final String MSG_PRECEDED = "ws.preceded";
060
061    /**
062     * A key is pointing to the warning message text in "messages.properties"
063     * file.
064     */
065    public static final String MSG_NOT_PRECEDED = "ws.notPreceded";
066
067    /** Semicolon literal. */
068    private static final String SEMICOLON = ";";
069
070    /** The policy to enforce. */
071    private PadOption option = PadOption.NOSPACE;
072
073    /**
074     * Set the option to enforce.
075     * @param optionStr string to decode option from
076     * @throws IllegalArgumentException if unable to decode
077     */
078    public void setOption(String optionStr) {
079        try {
080            option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
081        }
082        catch (IllegalArgumentException iae) {
083            throw new IllegalArgumentException("unable to parse " + optionStr, iae);
084        }
085    }
086
087    @Override
088    public int[] getDefaultTokens() {
089        return getRequiredTokens();
090    }
091
092    @Override
093    public int[] getAcceptableTokens() {
094        return getRequiredTokens();
095    }
096
097    @Override
098    public int[] getRequiredTokens() {
099        return new int[] {TokenTypes.FOR_INIT};
100    }
101
102    @Override
103    public void visitToken(DetailAST ast) {
104        if (ast.getChildCount() == 0) {
105            //empty for initializer. test pad before semi.
106            final DetailAST semi = ast.getNextSibling();
107            final int semiLineIdx = semi.getLineNo() - 1;
108            final String line = getLines()[semiLineIdx];
109            final int before = semi.getColumnNo() - 1;
110            //don't check if semi at beginning of line
111            if (!CommonUtil.hasWhitespaceBefore(before, line)) {
112                if (option == PadOption.NOSPACE
113                    && Character.isWhitespace(line.charAt(before))) {
114                    log(semi.getLineNo(), before, MSG_PRECEDED, SEMICOLON);
115                }
116                else if (option == PadOption.SPACE
117                         && !Character.isWhitespace(line.charAt(before))) {
118                    log(semi.getLineNo(), before, MSG_NOT_PRECEDED, SEMICOLON);
119                }
120            }
121        }
122    }
123
124}