001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 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 * <pre>
038 * for (
039 *     ; i &lt; j; i++, j--)
040 *  </pre>
041 * <ul>
042 * <li>
043 * Property {@code option} - Specify policy on how to pad an empty for iterator.
044 * Type is {@code com.puppycrawl.tools.checkstyle.checks.whitespace.PadOption}.
045 * Default value is {@code nospace}.
046 * </li>
047 * </ul>
048 *
049 * <p>
050 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
051 * </p>
052 *
053 * <p>
054 * Violation Message Keys:
055 * </p>
056 * <ul>
057 * <li>
058 * {@code ws.notPreceded}
059 * </li>
060 * <li>
061 * {@code ws.preceded}
062 * </li>
063 * </ul>
064 *
065 * @since 3.4
066 */
067@StatelessCheck
068public class EmptyForInitializerPadCheck
069    extends AbstractCheck {
070
071    /**
072     * A key is pointing to the warning message text in "messages.properties"
073     * file.
074     */
075    public static final String MSG_PRECEDED = "ws.preceded";
076
077    /**
078     * A key is pointing to the warning message text in "messages.properties"
079     * file.
080     */
081    public static final String MSG_NOT_PRECEDED = "ws.notPreceded";
082
083    /** Semicolon literal. */
084    private static final String SEMICOLON = ";";
085
086    /** Specify policy on how to pad an empty for iterator. */
087    private PadOption option = PadOption.NOSPACE;
088
089    /**
090     * Setter to specify policy on how to pad an empty for iterator.
091     *
092     * @param optionStr string to decode option from
093     * @throws IllegalArgumentException if unable to decode
094     * @since 3.4
095     */
096    public void setOption(String optionStr) {
097        option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
098    }
099
100    @Override
101    public int[] getDefaultTokens() {
102        return getRequiredTokens();
103    }
104
105    @Override
106    public int[] getAcceptableTokens() {
107        return getRequiredTokens();
108    }
109
110    @Override
111    public int[] getRequiredTokens() {
112        return new int[] {TokenTypes.FOR_INIT};
113    }
114
115    @Override
116    public void visitToken(DetailAST ast) {
117        if (!ast.hasChildren()) {
118            final int lineIdx = ast.getLineNo() - 1;
119            final int[] line = getLineCodePoints(lineIdx);
120            final int before = ast.getColumnNo() - 1;
121            // don't check if semi at beginning of line
122            if (ast.getColumnNo() > 0 && !CodePointUtil.hasWhitespaceBefore(before, line)) {
123                if (option == PadOption.NOSPACE
124                    && CommonUtil.isCodePointWhitespace(line, before)) {
125                    log(ast, MSG_PRECEDED, SEMICOLON);
126                }
127                else if (option == PadOption.SPACE
128                         && !CommonUtil.isCodePointWhitespace(line, before)) {
129                    log(ast, MSG_NOT_PRECEDED, SEMICOLON);
130                }
131            }
132        }
133    }
134
135}