001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2014  Oliver Burn
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////////////////////////////////////////////////////////////////////////////////
019package com.puppycrawl.tools.checkstyle.checks.whitespace;
020
021import com.puppycrawl.tools.checkstyle.api.DetailAST;
022import com.puppycrawl.tools.checkstyle.api.TokenTypes;
023import com.puppycrawl.tools.checkstyle.api.Utils;
024import com.puppycrawl.tools.checkstyle.checks.AbstractOptionCheck;
025
026/**
027 * <p>
028 * Checks the padding between the identifier of a method definition,
029 * constructor definition, method call, or constructor invocation;
030 * and the left parenthesis of the parameter list.
031 * That is, if the identifier and left parenthesis are on the same line,
032 * checks whether a space is required immediately after the identifier or
033 * such a space is forbidden.
034 * If they are not on the same line, reports an error, unless configured to
035 * allow line breaks.
036 * </p>
037 * <p> By default the check will check the following tokens:
038 *  {@link TokenTypes#CTOR_DEF CTOR_DEF},
039 *  {@link TokenTypes#LITERAL_NEW LITERAL_NEW},
040 *  {@link TokenTypes#METHOD_CALL METHOD_CALL},
041 *  {@link TokenTypes#METHOD_DEF METHOD_DEF},
042 *  {@link TokenTypes#SUPER_CTOR_CALL SUPER_CTOR_CALL}.
043 * </p>
044 * <p>
045 * An example of how to configure the check is:
046 * </p>
047 * <pre>
048 * &lt;module name="MethodParamPad"/&gt;
049 * </pre>
050 * <p> An example of how to configure the check to require a space
051 * after the identifier of a method definition, except if the left
052 * parenthesis occurs on a new line, is:
053 * </p>
054 * <pre>
055 * &lt;module name="MethodParamPad"&gt;
056 *     &lt;property name="tokens" value="METHOD_DEF"/&gt;
057 *     &lt;property name="option" value="space"/&gt;
058 *     &lt;property name="allowLineBreaks" value="true"/&gt;
059 * &lt;/module&gt;
060 * </pre>
061 * @author Rick Giles
062 * @version 1.0
063 */
064
065public class MethodParamPadCheck
066    extends AbstractOptionCheck<PadOption>
067{
068    /**
069     * Sets the pad option to nospace.
070     */
071    public MethodParamPadCheck()
072    {
073        super(PadOption.NOSPACE, PadOption.class);
074    }
075
076    /** Whether whitespace is allowed if the method identifier is at a
077     * linebreak */
078    private boolean allowLineBreaks;
079
080    @Override
081    public int[] getDefaultTokens()
082    {
083        return new int[] {
084            TokenTypes.CTOR_DEF,
085            TokenTypes.LITERAL_NEW,
086            TokenTypes.METHOD_CALL,
087            TokenTypes.METHOD_DEF,
088            TokenTypes.SUPER_CTOR_CALL,
089        };
090    }
091
092    @Override
093    public void visitToken(DetailAST ast)
094    {
095        final DetailAST parenAST;
096        if ((ast.getType() == TokenTypes.METHOD_CALL)) {
097            parenAST = ast;
098        }
099        else {
100            parenAST = ast.findFirstToken(TokenTypes.LPAREN);
101            // array construction => parenAST == null
102            if (parenAST == null) {
103                return;
104            }
105        }
106
107        final String line = getLines()[parenAST.getLineNo() - 1];
108        if (Utils.whitespaceBefore(parenAST.getColumnNo(), line)) {
109            if (!allowLineBreaks) {
110                log(parenAST, "line.previous", parenAST.getText());
111            }
112        }
113        else {
114            final int before = parenAST.getColumnNo() - 1;
115            if ((PadOption.NOSPACE == getAbstractOption())
116                && (Character.isWhitespace(line.charAt(before))))
117            {
118                log(parenAST , "ws.preceded", parenAST.getText());
119            }
120            else if ((PadOption.SPACE == getAbstractOption())
121                     && !Character.isWhitespace(line.charAt(before)))
122            {
123                log(parenAST, "ws.notPreceded", parenAST.getText());
124            }
125        }
126    }
127
128    /**
129     * Control whether whitespace is flagged at linebreaks.
130     * @param allowLineBreaks whether whitespace should be
131     * flagged at linebreaks.
132     */
133    public void setAllowLineBreaks(boolean allowLineBreaks)
134    {
135        this.allowLineBreaks = allowLineBreaks;
136    }
137}