001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2019 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.CommonUtil; 029 030/** 031 * <p> 032 * Checks the padding between the identifier of a method definition, 033 * constructor definition, method call, or constructor invocation; 034 * and the left parenthesis of the parameter list. 035 * That is, if the identifier and left parenthesis are on the same line, 036 * checks whether a space is required immediately after the identifier or 037 * such a space is forbidden. 038 * If they are not on the same line, reports a violation, unless configured to 039 * allow line breaks. To allow linebreaks after the identifier, set property 040 * {@code allowLineBreaks} to {@code true}. 041 * </p> 042 * <ul> 043 * <li> 044 * Property {@code allowLineBreaks} - Allow a line break between the identifier 045 * and left parenthesis. 046 * Default value is {@code false}. 047 * </li> 048 * <li> 049 * Property {@code option} - Specify policy on how to pad method parameter. 050 * Default value is {@code nospace}. 051 * </li> 052 * <li> 053 * Property {@code tokens} - tokens to check 054 * Default value is: 055 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF"> 056 * CTOR_DEF</a>, 057 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LITERAL_NEW"> 058 * LITERAL_NEW</a>, 059 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_CALL"> 060 * METHOD_CALL</a>, 061 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF"> 062 * METHOD_DEF</a>, 063 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL"> 064 * SUPER_CTOR_CALL</a>, 065 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_CONSTANT_DEF"> 066 * ENUM_CONSTANT_DEF</a>. 067 * </li> 068 * </ul> 069 * <p> 070 * To configure the check: 071 * </p> 072 * <pre> 073 * <module name="MethodParamPad"/> 074 * </pre> 075 * <p> 076 * To configure the check to require a space 077 * after the identifier of a method definition, except if the left 078 * parenthesis occurs on a new line: 079 * </p> 080 * <pre> 081 * <module name="MethodParamPad"> 082 * <property name="tokens" value="METHOD_DEF"/> 083 * <property name="option" value="space"/> 084 * <property name="allowLineBreaks" value="true"/> 085 * </module> 086 * </pre> 087 * 088 * @since 3.4 089 */ 090 091@StatelessCheck 092public class MethodParamPadCheck 093 extends AbstractCheck { 094 095 /** 096 * A key is pointing to the warning message text in "messages.properties" 097 * file. 098 */ 099 public static final String MSG_LINE_PREVIOUS = "line.previous"; 100 101 /** 102 * A key is pointing to the warning message text in "messages.properties" 103 * file. 104 */ 105 public static final String MSG_WS_PRECEDED = "ws.preceded"; 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_NOT_PRECEDED = "ws.notPreceded"; 112 113 /** 114 * Allow a line break between the identifier and left parenthesis. 115 */ 116 private boolean allowLineBreaks; 117 118 /** Specify policy on how to pad method parameter. */ 119 private PadOption option = PadOption.NOSPACE; 120 121 @Override 122 public int[] getDefaultTokens() { 123 return getAcceptableTokens(); 124 } 125 126 @Override 127 public int[] getAcceptableTokens() { 128 return new int[] { 129 TokenTypes.CTOR_DEF, 130 TokenTypes.LITERAL_NEW, 131 TokenTypes.METHOD_CALL, 132 TokenTypes.METHOD_DEF, 133 TokenTypes.SUPER_CTOR_CALL, 134 TokenTypes.ENUM_CONSTANT_DEF, 135 }; 136 } 137 138 @Override 139 public int[] getRequiredTokens() { 140 return CommonUtil.EMPTY_INT_ARRAY; 141 } 142 143 @Override 144 public void visitToken(DetailAST ast) { 145 final DetailAST parenAST; 146 if (ast.getType() == TokenTypes.METHOD_CALL) { 147 parenAST = ast; 148 } 149 else { 150 parenAST = ast.findFirstToken(TokenTypes.LPAREN); 151 // array construction => parenAST == null 152 } 153 154 if (parenAST != null) { 155 final String line = getLines()[parenAST.getLineNo() - 1]; 156 if (CommonUtil.hasWhitespaceBefore(parenAST.getColumnNo(), line)) { 157 if (!allowLineBreaks) { 158 log(parenAST, MSG_LINE_PREVIOUS, parenAST.getText()); 159 } 160 } 161 else { 162 final int before = parenAST.getColumnNo() - 1; 163 if (option == PadOption.NOSPACE 164 && Character.isWhitespace(line.charAt(before))) { 165 log(parenAST, MSG_WS_PRECEDED, parenAST.getText()); 166 } 167 else if (option == PadOption.SPACE 168 && !Character.isWhitespace(line.charAt(before))) { 169 log(parenAST, MSG_WS_NOT_PRECEDED, parenAST.getText()); 170 } 171 } 172 } 173 } 174 175 /** 176 * Setter to allow a line break between the identifier and left parenthesis. 177 * @param allowLineBreaks whether whitespace should be 178 * flagged at line breaks. 179 */ 180 public void setAllowLineBreaks(boolean allowLineBreaks) { 181 this.allowLineBreaks = allowLineBreaks; 182 } 183 184 /** 185 * Setter to specify policy on how to pad method parameter. 186 * @param optionStr string to decode option from 187 * @throws IllegalArgumentException if unable to decode 188 */ 189 public void setOption(String optionStr) { 190 option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH)); 191 } 192 193}