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 java.util.Locale;
023
024import org.apache.commons.beanutils.ConversionException;
025import org.apache.commons.lang3.ArrayUtils;
026
027import com.puppycrawl.tools.checkstyle.api.Check;
028import com.puppycrawl.tools.checkstyle.api.DetailAST;
029import com.puppycrawl.tools.checkstyle.api.TokenTypes;
030import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
031
032/**
033 * <p>
034 * Checks the padding between the identifier of a method definition,
035 * constructor definition, method call, or constructor invocation;
036 * and the left parenthesis of the parameter list.
037 * That is, if the identifier and left parenthesis are on the same line,
038 * checks whether a space is required immediately after the identifier or
039 * such a space is forbidden.
040 * If they are not on the same line, reports an error, unless configured to
041 * allow line breaks.
042 * </p>
043 * <p> By default the check will check the following tokens:
044 *  {@link TokenTypes#CTOR_DEF CTOR_DEF},
045 *  {@link TokenTypes#LITERAL_NEW LITERAL_NEW},
046 *  {@link TokenTypes#METHOD_CALL METHOD_CALL},
047 *  {@link TokenTypes#METHOD_DEF METHOD_DEF},
048 *  {@link TokenTypes#SUPER_CTOR_CALL SUPER_CTOR_CALL}.
049 * </p>
050 * <p>
051 * An example of how to configure the check is:
052 * </p>
053 * <pre>
054 * &lt;module name="MethodParamPad"/&gt;
055 * </pre>
056 * <p> An example of how to configure the check to require a space
057 * after the identifier of a method definition, except if the left
058 * parenthesis occurs on a new line, is:
059 * </p>
060 * <pre>
061 * &lt;module name="MethodParamPad"&gt;
062 *     &lt;property name="tokens" value="METHOD_DEF"/&gt;
063 *     &lt;property name="option" value="space"/&gt;
064 *     &lt;property name="allowLineBreaks" value="true"/&gt;
065 * &lt;/module&gt;
066 * </pre>
067 * @author Rick Giles
068 */
069
070public class MethodParamPadCheck
071    extends Check {
072
073    /**
074     * A key is pointing to the warning message text in "messages.properties"
075     * file.
076     */
077    public static final String LINE_PREVIOUS = "line.previous";
078
079    /**
080     * A key is pointing to the warning message text in "messages.properties"
081     * file.
082     */
083    public static final String WS_PRECEDED = "ws.preceded";
084
085    /**
086     * A key is pointing to the warning message text in "messages.properties"
087     * file.
088     */
089    public static final String WS_NOT_PRECEDED = "ws.notPreceded";
090
091    /**
092     * Whether whitespace is allowed if the method identifier is at a
093     * linebreak.
094     */
095    private boolean allowLineBreaks;
096
097    /** The policy to enforce. */
098    private PadOption option = PadOption.NOSPACE;
099
100    @Override
101    public int[] getDefaultTokens() {
102        return getAcceptableTokens();
103    }
104
105    @Override
106    public int[] getAcceptableTokens() {
107        return new int[] {
108            TokenTypes.CTOR_DEF,
109            TokenTypes.LITERAL_NEW,
110            TokenTypes.METHOD_CALL,
111            TokenTypes.METHOD_DEF,
112            TokenTypes.SUPER_CTOR_CALL,
113        };
114    }
115
116    @Override
117    public int[] getRequiredTokens() {
118        return ArrayUtils.EMPTY_INT_ARRAY;
119    }
120
121    @Override
122    public void visitToken(DetailAST ast) {
123        final DetailAST parenAST;
124        if (ast.getType() == TokenTypes.METHOD_CALL) {
125            parenAST = ast;
126        }
127        else {
128            parenAST = ast.findFirstToken(TokenTypes.LPAREN);
129            // array construction => parenAST == null
130            if (parenAST == null) {
131                return;
132            }
133        }
134
135        final String line = getLines()[parenAST.getLineNo() - 1];
136        if (CommonUtils.hasWhitespaceBefore(parenAST.getColumnNo(), line)) {
137            if (!allowLineBreaks) {
138                log(parenAST, LINE_PREVIOUS, parenAST.getText());
139            }
140        }
141        else {
142            final int before = parenAST.getColumnNo() - 1;
143            if (option == PadOption.NOSPACE
144                && Character.isWhitespace(line.charAt(before))) {
145                log(parenAST, WS_PRECEDED, parenAST.getText());
146            }
147            else if (option == PadOption.SPACE
148                     && !Character.isWhitespace(line.charAt(before))) {
149                log(parenAST, WS_NOT_PRECEDED, parenAST.getText());
150            }
151        }
152    }
153
154    /**
155     * Control whether whitespace is flagged at line breaks.
156     * @param allowLineBreaks whether whitespace should be
157     *     flagged at line breaks.
158     */
159    public void setAllowLineBreaks(boolean allowLineBreaks) {
160        this.allowLineBreaks = allowLineBreaks;
161    }
162
163    /**
164     * Set the option to enforce.
165     * @param optionStr string to decode option from
166     * @throws ConversionException if unable to decode
167     */
168    public void setOption(String optionStr) {
169        try {
170            option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
171        }
172        catch (IllegalArgumentException iae) {
173            throw new ConversionException("unable to parse " + optionStr, iae);
174        }
175    }
176}