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 * <p> 033 * Checks the padding between the identifier of a method definition, 034 * constructor definition, method call, or constructor invocation; 035 * and the left parenthesis of the parameter list. 036 * That is, if the identifier and left parenthesis are on the same line, 037 * checks whether a space is required immediately after the identifier or 038 * such a space is forbidden. 039 * If they are not on the same line, reports a violation, unless configured to 040 * allow line breaks. To allow linebreaks after the identifier, set property 041 * {@code allowLineBreaks} to {@code true}. 042 * </p> 043 * <ul> 044 * <li> 045 * Property {@code allowLineBreaks} - Allow a line break between the identifier 046 * and left parenthesis. 047 * Type is {@code boolean}. 048 * Default value is {@code false}. 049 * </li> 050 * <li> 051 * Property {@code option} - Specify policy on how to pad method parameter. 052 * Type is {@code com.puppycrawl.tools.checkstyle.checks.whitespace.PadOption}. 053 * Default value is {@code nospace}. 054 * </li> 055 * <li> 056 * Property {@code tokens} - tokens to check 057 * Type is {@code java.lang.String[]}. 058 * Validation type is {@code tokenSet}. 059 * Default value is: 060 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF"> 061 * CTOR_DEF</a>, 062 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LITERAL_NEW"> 063 * LITERAL_NEW</a>, 064 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_CALL"> 065 * METHOD_CALL</a>, 066 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF"> 067 * METHOD_DEF</a>, 068 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL"> 069 * SUPER_CTOR_CALL</a>, 070 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_CONSTANT_DEF"> 071 * ENUM_CONSTANT_DEF</a>, 072 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RECORD_DEF"> 073 * RECORD_DEF</a>. 074 * </li> 075 * </ul> 076 * <p> 077 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 078 * </p> 079 * <p> 080 * Violation Message Keys: 081 * </p> 082 * <ul> 083 * <li> 084 * {@code line.previous} 085 * </li> 086 * <li> 087 * {@code ws.notPreceded} 088 * </li> 089 * <li> 090 * {@code ws.preceded} 091 * </li> 092 * </ul> 093 * 094 * @since 3.4 095 */ 096 097@StatelessCheck 098public class MethodParamPadCheck 099 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}