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Checkstyle is a development tool to help programmers write Java code
that adheres to a coding standard
////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2022 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.whitespace;
import java.util.Locale;
import com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.CodePointUtil;
import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
/**
*
* Checks the padding between the identifier of a method definition,
* constructor definition, method call, or constructor invocation;
* and the left parenthesis of the parameter list.
* That is, if the identifier and left parenthesis are on the same line,
* checks whether a space is required immediately after the identifier or
* such a space is forbidden.
* If they are not on the same line, reports a violation, unless configured to
* allow line breaks. To allow linebreaks after the identifier, set property
* {@code allowLineBreaks} to {@code true}.
*
*
* -
* Property {@code allowLineBreaks} - Allow a line break between the identifier
* and left parenthesis.
* Type is {@code boolean}.
* Default value is {@code false}.
*
* -
* Property {@code option} - Specify policy on how to pad method parameter.
* Type is {@code com.puppycrawl.tools.checkstyle.checks.whitespace.PadOption}.
* Default value is {@code nospace}.
*
* -
* Property {@code tokens} - tokens to check
* Type is {@code java.lang.String[]}.
* Validation type is {@code tokenSet}.
* Default value is:
*
* CTOR_DEF,
*
* LITERAL_NEW,
*
* METHOD_CALL,
*
* METHOD_DEF,
*
* SUPER_CTOR_CALL,
*
* ENUM_CONSTANT_DEF,
*
* RECORD_DEF.
*
*
*
* To configure the check:
*
*
* <module name="MethodParamPad"/>
*
*
* public class Test {
* public Test() { // OK
* super(); // OK
* }
*
* public Test (int aParam) { // Violation - '(' is preceded with whitespace
* super (); // Violation - '(' is preceded with whitespace
* }
*
* public void method() {} // OK
*
* public void methodWithVeryLongName
* () {} // Violation - '(' is preceded with whitespace
*
* }
*
*
* To configure the check to require a space
* after the identifier of a method definition, except if the left
* parenthesis occurs on a new line:
*
*
* <module name="MethodParamPad">
* <property name="tokens" value="METHOD_DEF"/>
* <property name="option" value="space"/>
* <property name="allowLineBreaks" value="true"/>
* </module>
*
*
* public class Test {
* public Test() { // OK
* super(); // OK
* }
*
* public Test (int aParam) { // OK
* super (); // OK
* }
*
* public void method() {} // Violation - '(' is NOT preceded with whitespace
*
* public void methodWithVeryLongName
* () {} // OK, because allowLineBreaks is true
*
* }
*
*
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
*
*
* Violation Message Keys:
*
*
* -
* {@code line.previous}
*
* -
* {@code ws.notPreceded}
*
* -
* {@code ws.preceded}
*
*
*
* @since 3.4
*/
@StatelessCheck
public class MethodParamPadCheck
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_LINE_PREVIOUS = "line.previous";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_WS_PRECEDED = "ws.preceded";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_WS_NOT_PRECEDED = "ws.notPreceded";
/**
* Allow a line break between the identifier and left parenthesis.
*/
private boolean allowLineBreaks;
/** Specify policy on how to pad method parameter. */
private PadOption option = PadOption.NOSPACE;
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.CTOR_DEF,
TokenTypes.LITERAL_NEW,
TokenTypes.METHOD_CALL,
TokenTypes.METHOD_DEF,
TokenTypes.SUPER_CTOR_CALL,
TokenTypes.ENUM_CONSTANT_DEF,
TokenTypes.RECORD_DEF,
};
}
@Override
public int[] getRequiredTokens() {
return CommonUtil.EMPTY_INT_ARRAY;
}
@Override
public void visitToken(DetailAST ast) {
final DetailAST parenAST;
if (ast.getType() == TokenTypes.METHOD_CALL) {
parenAST = ast;
}
else {
parenAST = ast.findFirstToken(TokenTypes.LPAREN);
// array construction => parenAST == null
}
if (parenAST != null) {
final int[] line = getLineCodePoints(parenAST.getLineNo() - 1);
if (CodePointUtil.hasWhitespaceBefore(parenAST.getColumnNo(), line)) {
if (!allowLineBreaks) {
log(parenAST, MSG_LINE_PREVIOUS, parenAST.getText());
}
}
else {
final int before = parenAST.getColumnNo() - 1;
if (option == PadOption.NOSPACE
&& CommonUtil.isCodePointWhitespace(line, before)) {
log(parenAST, MSG_WS_PRECEDED, parenAST.getText());
}
else if (option == PadOption.SPACE
&& !CommonUtil.isCodePointWhitespace(line, before)) {
log(parenAST, MSG_WS_NOT_PRECEDED, parenAST.getText());
}
}
}
}
/**
* Setter to allow a line break between the identifier and left parenthesis.
*
* @param allowLineBreaks whether whitespace should be
* flagged at line breaks.
*/
public void setAllowLineBreaks(boolean allowLineBreaks) {
this.allowLineBreaks = allowLineBreaks;
}
/**
* Setter to specify policy on how to pad method parameter.
*
* @param optionStr string to decode option from
* @throws IllegalArgumentException if unable to decode
*/
public void setOption(String optionStr) {
option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
}
}