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.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.CodePointUtil;
029import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
030
031/**
032 * <div>
033 * Checks the padding of an empty for initializer; that is whether a white
034 * space is required at an empty for initializer, or such white space is
035 * forbidden. No check occurs if there is a line wrap at the initializer, as in
036 * </div>
037 * {@snippet lang="text" :
038 * for (
039 *     ; i < j; i++, j--)
040 * }
041 *
042 * @since 3.4
043 */
044@StatelessCheck
045public class EmptyForInitializerPadCheck extends AbstractCheck {
046
047    /**
048     * A key is pointing to the warning message text in "messages.properties" file.
049     */
050    public static final String MSG_PRECEDED = "ws.preceded";
051
052    /**
053     * A key is pointing to the warning message text in "messages.properties" file.
054     */
055    public static final String MSG_NOT_PRECEDED = "ws.notPreceded";
056
057    /** Semicolon literal. */
058    private static final String SEMICOLON = ";";
059
060    /** Specify policy on how to pad an empty for iterator. */
061    private PadOption option = PadOption.NOSPACE;
062
063    /**
064     * Creates a new {@code EmptyForInitializerPadCheck} instance.
065     */
066    public EmptyForInitializerPadCheck() {
067        // no code by default
068    }
069
070    /**
071     * Setter to specify policy on how to pad an empty for iterator.
072     *
073     * @param optionStr string to decode option from
074     * @throws IllegalArgumentException if unable to decode
075     * @since 3.4
076     */
077    public void setOption(String optionStr) {
078        option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
079    }
080
081    @Override
082    public int[] getDefaultTokens() {
083        return getRequiredTokens();
084    }
085
086    @Override
087    public int[] getAcceptableTokens() {
088        return getRequiredTokens();
089    }
090
091    @Override
092    public int[] getRequiredTokens() {
093        return new int[] {TokenTypes.FOR_INIT};
094    }
095
096    @Override
097    public void visitToken(DetailAST ast) {
098        if (!ast.hasChildren()) {
099            final int lineIdx = ast.getLineNo() - 1;
100            final int[] line = getLineCodePoints(lineIdx);
101            final int before = ast.getColumnNo() - 1;
102            // don't check if semi at beginning of line
103            if (ast.getColumnNo() > 0 && !CodePointUtil.hasWhitespaceBefore(before, line)) {
104                if (option == PadOption.NOSPACE
105                    && CommonUtil.isCodePointWhitespace(line, before)) {
106                    log(ast, MSG_PRECEDED, SEMICOLON);
107                }
108                else if (option == PadOption.SPACE
109                         && !CommonUtil.isCodePointWhitespace(line, before)) {
110                    log(ast, MSG_NOT_PRECEDED, SEMICOLON);
111                }
112            }
113        }
114    }
115
116}