001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 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.CommonUtils;
029
030/**
031 * <p>
032 * Checks line wrapping for operators.
033 * The policy to verify is specified using the {@link WrapOption} class
034 * and defaults to {@link WrapOption#NL}.
035 * </p>
036 * <p> By default the check will check the following operators:
037 *  {@link TokenTypes#BAND BAND},
038 *  {@link TokenTypes#BOR BOR},
039 *  {@link TokenTypes#BSR BSR},
040 *  {@link TokenTypes#BXOR BXOR},
041 *  {@link TokenTypes#COLON COLON},
042 *  {@link TokenTypes#DIV DIV},
043 *  {@link TokenTypes#EQUAL EQUAL},
044 *  {@link TokenTypes#GE GE},
045 *  {@link TokenTypes#GT GT},
046 *  {@link TokenTypes#LAND LAND},
047 *  {@link TokenTypes#LE LE},
048 *  {@link TokenTypes#LITERAL_INSTANCEOF LITERAL_INSTANCEOF},
049 *  {@link TokenTypes#LOR LOR},
050 *  {@link TokenTypes#LT LT},
051 *  {@link TokenTypes#MINUS MINUS},
052 *  {@link TokenTypes#MOD MOD},
053 *  {@link TokenTypes#NOT_EQUAL NOT_EQUAL},
054 *  {@link TokenTypes#PLUS PLUS},
055 *  {@link TokenTypes#QUESTION QUESTION},
056 *  {@link TokenTypes#SL SL},
057 *  {@link TokenTypes#SR SR},
058 *  {@link TokenTypes#STAR STAR}.
059 * Other acceptable tokens are
060 *  {@link TokenTypes#ASSIGN ASSIGN},
061 *  {@link TokenTypes#BAND_ASSIGN BAND_ASSIGN},
062 *  {@link TokenTypes#BOR_ASSIGN BOR_ASSIGN},
063 *  {@link TokenTypes#BSR_ASSIGN BSR_ASSIGN},
064 *  {@link TokenTypes#BXOR_ASSIGN BXOR_ASSIGN},
065 *  {@link TokenTypes#DIV_ASSIGN DIV_ASSIGN},
066 *  {@link TokenTypes#MINUS_ASSIGN MINUS_ASSIGN},
067 *  {@link TokenTypes#MOD_ASSIGN MOD_ASSIGN},
068 *  {@link TokenTypes#PLUS_ASSIGN PLUS_ASSIGN},
069 *  {@link TokenTypes#SL_ASSIGN SL_ASSIGN},
070 *  {@link TokenTypes#SR_ASSIGN SR_ASSIGN},
071 *  {@link TokenTypes#STAR_ASSIGN STAR_ASSIGN}.
072 *  {@link TokenTypes#METHOD_REF METHOD_REF}.
073 * </p>
074 *  <p>
075 * An example of how to configure the check is:
076 * </p>
077 * <pre>
078 * &lt;module name="OperatorWrap"/&gt;
079 * </pre>
080 * <p> An example of how to configure the check for assignment operators at the
081 * end of a line is:
082 * </p>
083 * <pre>
084 * &lt;module name="OperatorWrap"&gt;
085 *     &lt;property name="tokens"
086 *               value="ASSIGN,DIV_ASSIGN,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN,MOD_ASSIGN
087 *               ,SR_ASSIGN,BSR_ASSIGN,SL_ASSIGN,BXOR_ASSIGN,BOR_ASSIGN,BAND_ASSIGN"/&gt;
088 *     &lt;property name="option" value="eol"/&gt;
089 * &lt;/module&gt;
090 * </pre>
091 *
092 * @author Rick Giles
093 */
094@StatelessCheck
095public class OperatorWrapCheck
096    extends AbstractCheck {
097
098    /**
099     * A key is pointing to the warning message text in "messages.properties"
100     * file.
101     */
102    public static final String MSG_LINE_NEW = "line.new";
103
104    /**
105     * A key is pointing to the warning message text in "messages.properties"
106     * file.
107     */
108    public static final String MSG_LINE_PREVIOUS = "line.previous";
109
110    /** The policy to enforce. */
111    private WrapOption option = WrapOption.NL;
112
113    /**
114     * Set the option to enforce.
115     * @param optionStr string to decode option from
116     * @throws IllegalArgumentException if unable to decode
117     */
118    public void setOption(String optionStr) {
119        try {
120            option = WrapOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
121        }
122        catch (IllegalArgumentException iae) {
123            throw new IllegalArgumentException("unable to parse " + optionStr, iae);
124        }
125    }
126
127    @Override
128    public int[] getDefaultTokens() {
129        return new int[] {
130            TokenTypes.QUESTION,          // '?'
131            TokenTypes.COLON,             // ':' (not reported for a case)
132            TokenTypes.EQUAL,             // "=="
133            TokenTypes.NOT_EQUAL,         // "!="
134            TokenTypes.DIV,               // '/'
135            TokenTypes.PLUS,              //' +' (unary plus is UNARY_PLUS)
136            TokenTypes.MINUS,             // '-' (unary minus is UNARY_MINUS)
137            TokenTypes.STAR,              // '*'
138            TokenTypes.MOD,               // '%'
139            TokenTypes.SR,                // ">>"
140            TokenTypes.BSR,               // ">>>"
141            TokenTypes.GE,                // ">="
142            TokenTypes.GT,                // ">"
143            TokenTypes.SL,                // "<<"
144            TokenTypes.LE,                // "<="
145            TokenTypes.LT,                // '<'
146            TokenTypes.BXOR,              // '^'
147            TokenTypes.BOR,               // '|'
148            TokenTypes.LOR,               // "||"
149            TokenTypes.BAND,              // '&'
150            TokenTypes.LAND,              // "&&"
151            TokenTypes.TYPE_EXTENSION_AND,
152            TokenTypes.LITERAL_INSTANCEOF,
153        };
154    }
155
156    @Override
157    public int[] getAcceptableTokens() {
158        return new int[] {
159            TokenTypes.QUESTION,          // '?'
160            TokenTypes.COLON,             // ':' (not reported for a case)
161            TokenTypes.EQUAL,             // "=="
162            TokenTypes.NOT_EQUAL,         // "!="
163            TokenTypes.DIV,               // '/'
164            TokenTypes.PLUS,              //' +' (unary plus is UNARY_PLUS)
165            TokenTypes.MINUS,             // '-' (unary minus is UNARY_MINUS)
166            TokenTypes.STAR,              // '*'
167            TokenTypes.MOD,               // '%'
168            TokenTypes.SR,                // ">>"
169            TokenTypes.BSR,               // ">>>"
170            TokenTypes.GE,                // ">="
171            TokenTypes.GT,                // ">"
172            TokenTypes.SL,                // "<<"
173            TokenTypes.LE,                // "<="
174            TokenTypes.LT,                // '<'
175            TokenTypes.BXOR,              // '^'
176            TokenTypes.BOR,               // '|'
177            TokenTypes.LOR,               // "||"
178            TokenTypes.BAND,              // '&'
179            TokenTypes.LAND,              // "&&"
180            TokenTypes.LITERAL_INSTANCEOF,
181            TokenTypes.TYPE_EXTENSION_AND,
182            TokenTypes.ASSIGN,            // '='
183            TokenTypes.DIV_ASSIGN,        // "/="
184            TokenTypes.PLUS_ASSIGN,       // "+="
185            TokenTypes.MINUS_ASSIGN,      //"-="
186            TokenTypes.STAR_ASSIGN,       // "*="
187            TokenTypes.MOD_ASSIGN,        // "%="
188            TokenTypes.SR_ASSIGN,         // ">>="
189            TokenTypes.BSR_ASSIGN,        // ">>>="
190            TokenTypes.SL_ASSIGN,         // "<<="
191            TokenTypes.BXOR_ASSIGN,       // "^="
192            TokenTypes.BOR_ASSIGN,        // "|="
193            TokenTypes.BAND_ASSIGN,       // "&="
194            TokenTypes.METHOD_REF,        // "::"
195
196        };
197    }
198
199    @Override
200    public int[] getRequiredTokens() {
201        return CommonUtils.EMPTY_INT_ARRAY;
202    }
203
204    @Override
205    public void visitToken(DetailAST ast) {
206        final DetailAST parent = ast.getParent();
207        //we do not want to check colon for cases and defaults
208        if (ast.getType() != TokenTypes.COLON
209                || parent.getType() != TokenTypes.LITERAL_DEFAULT
210                    && parent.getType() != TokenTypes.LITERAL_CASE) {
211            final String text = ast.getText();
212            final int colNo = ast.getColumnNo();
213            final int lineNo = ast.getLineNo();
214            final String currentLine = getLine(lineNo - 1);
215
216            // Check if rest of line is whitespace, and not just the operator
217            // by itself. This last bit is to handle the operator on a line by
218            // itself.
219            if (option == WrapOption.NL
220                    && !text.equals(currentLine.trim())
221                    && CommonUtils.isBlank(currentLine.substring(colNo + text.length()))) {
222                log(lineNo, colNo, MSG_LINE_NEW, text);
223            }
224            else if (option == WrapOption.EOL
225                    && CommonUtils.hasWhitespaceBefore(colNo - 1, currentLine)) {
226                log(lineNo, colNo, MSG_LINE_PREVIOUS, text);
227            }
228        }
229    }
230}