1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.whitespace;
21
22 import java.util.Locale;
23
24 import com.puppycrawl.tools.checkstyle.StatelessCheck;
25 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
26 import com.puppycrawl.tools.checkstyle.api.DetailAST;
27 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
28 import com.puppycrawl.tools.checkstyle.utils.CodePointUtil;
29 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
30
31 /**
32 * <p>
33 * Checks the padding between the identifier of a method definition,
34 * constructor definition, method call, or constructor invocation;
35 * and the left parenthesis of the parameter list.
36 * That is, if the identifier and left parenthesis are on the same line,
37 * checks whether a space is required immediately after the identifier or
38 * such a space is forbidden.
39 * If they are not on the same line, reports a violation, unless configured to
40 * allow line breaks. To allow linebreaks after the identifier, set property
41 * {@code allowLineBreaks} to {@code true}.
42 * </p>
43 * <ul>
44 * <li>
45 * Property {@code allowLineBreaks} - Allow a line break between the identifier
46 * and left parenthesis.
47 * Type is {@code boolean}.
48 * Default value is {@code false}.
49 * </li>
50 * <li>
51 * Property {@code option} - Specify policy on how to pad method parameter.
52 * Type is {@code com.puppycrawl.tools.checkstyle.checks.whitespace.PadOption}.
53 * Default value is {@code nospace}.
54 * </li>
55 * <li>
56 * Property {@code tokens} - tokens to check
57 * Type is {@code java.lang.String[]}.
58 * Validation type is {@code tokenSet}.
59 * Default value is:
60 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF">
61 * CTOR_DEF</a>,
62 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LITERAL_NEW">
63 * LITERAL_NEW</a>,
64 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_CALL">
65 * METHOD_CALL</a>,
66 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF">
67 * METHOD_DEF</a>,
68 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL">
69 * SUPER_CTOR_CALL</a>,
70 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_CONSTANT_DEF">
71 * ENUM_CONSTANT_DEF</a>,
72 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RECORD_DEF">
73 * RECORD_DEF</a>.
74 * </li>
75 * </ul>
76 * <p>
77 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
78 * </p>
79 * <p>
80 * Violation Message Keys:
81 * </p>
82 * <ul>
83 * <li>
84 * {@code line.previous}
85 * </li>
86 * <li>
87 * {@code ws.notPreceded}
88 * </li>
89 * <li>
90 * {@code ws.preceded}
91 * </li>
92 * </ul>
93 *
94 * @since 3.4
95 */
96
97 @StatelessCheck
98 public class MethodParamPadCheck
99 extends AbstractCheck {
100
101 /**
102 * A key is pointing to the warning message text in "messages.properties"
103 * file.
104 */
105 public static final String MSG_LINE_PREVIOUS = "line.previous";
106
107 /**
108 * A key is pointing to the warning message text in "messages.properties"
109 * file.
110 */
111 public static final String MSG_WS_PRECEDED = "ws.preceded";
112
113 /**
114 * A key is pointing to the warning message text in "messages.properties"
115 * file.
116 */
117 public static final String MSG_WS_NOT_PRECEDED = "ws.notPreceded";
118
119 /**
120 * Allow a line break between the identifier and left parenthesis.
121 */
122 private boolean allowLineBreaks;
123
124 /** Specify policy on how to pad method parameter. */
125 private PadOption option = PadOption.NOSPACE;
126
127 @Override
128 public int[] getDefaultTokens() {
129 return getAcceptableTokens();
130 }
131
132 @Override
133 public int[] getAcceptableTokens() {
134 return new int[] {
135 TokenTypes.CTOR_DEF,
136 TokenTypes.LITERAL_NEW,
137 TokenTypes.METHOD_CALL,
138 TokenTypes.METHOD_DEF,
139 TokenTypes.SUPER_CTOR_CALL,
140 TokenTypes.ENUM_CONSTANT_DEF,
141 TokenTypes.RECORD_DEF,
142 };
143 }
144
145 @Override
146 public int[] getRequiredTokens() {
147 return CommonUtil.EMPTY_INT_ARRAY;
148 }
149
150 @Override
151 public void visitToken(DetailAST ast) {
152 final DetailAST parenAST;
153 if (ast.getType() == TokenTypes.METHOD_CALL) {
154 parenAST = ast;
155 }
156 else {
157 parenAST = ast.findFirstToken(TokenTypes.LPAREN);
158 // array construction => parenAST == null
159 }
160
161 if (parenAST != null) {
162 final int[] line = getLineCodePoints(parenAST.getLineNo() - 1);
163 if (CodePointUtil.hasWhitespaceBefore(parenAST.getColumnNo(), line)) {
164 if (!allowLineBreaks) {
165 log(parenAST, MSG_LINE_PREVIOUS, parenAST.getText());
166 }
167 }
168 else {
169 final int before = parenAST.getColumnNo() - 1;
170 if (option == PadOption.NOSPACE
171 && CommonUtil.isCodePointWhitespace(line, before)) {
172 log(parenAST, MSG_WS_PRECEDED, parenAST.getText());
173 }
174 else if (option == PadOption.SPACE
175 && !CommonUtil.isCodePointWhitespace(line, before)) {
176 log(parenAST, MSG_WS_NOT_PRECEDED, parenAST.getText());
177 }
178 }
179 }
180 }
181
182 /**
183 * Setter to allow a line break between the identifier and left parenthesis.
184 *
185 * @param allowLineBreaks whether whitespace should be
186 * flagged at line breaks.
187 * @since 3.4
188 */
189 public void setAllowLineBreaks(boolean allowLineBreaks) {
190 this.allowLineBreaks = allowLineBreaks;
191 }
192
193 /**
194 * Setter to specify policy on how to pad method parameter.
195 *
196 * @param optionStr string to decode option from
197 * @throws IllegalArgumentException if unable to decode
198 * @since 3.4
199 */
200 public void setOption(String optionStr) {
201 option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
202 }
203
204 }