com.puppycrawl.tools.checkstyle.checks.blocks

Class LeftCurlyCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.puppycrawl.tools.checkstyle.checks.blocks.LeftCurlyCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class LeftCurlyCheck
extends AbstractCheck

Checks for the placement of left curly braces ('{') for code blocks.

• Property option - Specify the policy on placement of a left curly brace ('{'). Type is com.puppycrawl.tools.checkstyle.checks.blocks.LeftCurlyOption. Default value is eol.
• Property ignoreEnums - Allow to ignore enums when left curly brace policy is EOL. Type is boolean. Default value is true.
• Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF, INTERFACE_DEF, LAMBDA, LITERAL_CASE, LITERAL_CATCH, LITERAL_DEFAULT, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF, OBJBLOCK, STATIC_INIT, RECORD_DEF, COMPACT_CTOR_DEF.

To configure the check:

 <module name="LeftCurly"/>
 

 class Test
 { // Violation - '{' should be on the previous line
   private interface TestInterface
   { // Violation - '{' should be on the previous line
   }

   private
   class
   MyClass { // OK
   }

   enum Colors {RED, // OK
     BLUE,
     GREEN;
   }
 }
 

To configure the check to apply the nl policy to type blocks:

 <module name="LeftCurly">
   <property name="option" value="nl"/>
   <property name="tokens" value="CLASS_DEF,INTERFACE_DEF"/>
 </module>
 

 class Test
 { // OK
   private interface TestInterface
   { // OK
   }

   private
   class
   MyClass { // Violation - '{' should be on a new line
   }

   enum Colors {RED, // OK
     BLUE,
     GREEN;
   }
 }
 

An example of how to configure the check to validate enum definitions:

 <module name="LeftCurly">
   <property name="ignoreEnums" value="false"/>
 </module>
 

 class Test
 { // Violation - '{' should be on the previous line
   private interface TestInterface
   { // Violation - '{' should be on the previous line
   }

   private
   class
   MyClass { // OK
   }

   enum Colors {RED, // Violation - '{' should have line break after
   BLUE,
   GREEN;
   }
 }
 

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

• line.break.after
• line.new
• line.previous

Since:

3.0

Nested Class Summary

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

AutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	ignoreEnums Allow to ignore enums when left curly brace policy is EOL.
static java.lang.String	MSG_KEY_LINE_BREAK_AFTER A key is pointing to the warning message text in "messages.properties" file.
static java.lang.String	MSG_KEY_LINE_NEW A key is pointing to the warning message text in "messages.properties" file.
static java.lang.String	MSG_KEY_LINE_PREVIOUS A key is pointing to the warning message text in "messages.properties" file.
private static java.lang.String	OPEN_CURLY_BRACE Open curly brace literal.
private LeftCurlyOption	option Specify the policy on placement of a left curly brace ('{').

Constructor Summary

Constructors

Constructor and Description
LeftCurlyCheck()

Method Summary

Modifier and Type	Method and Description
private static DetailAST	findLastAnnotation(DetailAST modifiers) Find the last token of type TokenTypes.ANNOTATION under the given set of modifiers.
int[]	getAcceptableTokens() The configurable token set.
private static DetailAST	getBraceAsFirstChild(DetailAST ast) Gets a SLIST if it is the first child of the AST.
private static DetailAST	getBraceFromSwitchMember(DetailAST ast) Gets the brace of a switch statement/ expression member.
int[]	getDefaultTokens() Returns the default token a check is interested in.
int[]	getRequiredTokens() The tokens that this check must be registered for.
private boolean	hasLineBreakAfter(DetailAST leftCurly) Checks if left curly has line break after.
void	setIgnoreEnums(boolean ignoreEnums) Setter to allow to ignore enums when left curly brace policy is EOL.
void	setOption(java.lang.String optionStr) Setter to specify the policy on placement of a left curly brace ('{').
private static DetailAST	skipModifierAnnotations(DetailAST ast) Skip all TokenTypes.ANNOTATIONs to the first non-annotation.
private void	validateEol(DetailAST brace, java.lang.String braceLine) Validate EOL case.
private void	validateNewLinePosition(DetailAST brace, DetailAST startToken, java.lang.String braceLine) Validate token on new Line position.
private void	verifyBrace(DetailAST brace, DetailAST startToken) Verifies that a specified left curly brace is placed correctly according to policy.
void	visitToken(DetailAST ast) We cannot reduce the number of branches in this switch statement, since many tokens require specific methods to find the first left curly.

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck

beginTree, clearViolations, destroy, finishTree, getFileContents, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MSG_KEY_LINE_NEW

public static final java.lang.String MSG_KEY_LINE_NEW

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

MSG_KEY_LINE_PREVIOUS

public static final java.lang.String MSG_KEY_LINE_PREVIOUS

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

MSG_KEY_LINE_BREAK_AFTER

public static final java.lang.String MSG_KEY_LINE_BREAK_AFTER

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

OPEN_CURLY_BRACE

private static final java.lang.String OPEN_CURLY_BRACE

Open curly brace literal.

See Also:

Constant Field Values

ignoreEnums

private boolean ignoreEnums

Allow to ignore enums when left curly brace policy is EOL.

option

private LeftCurlyOption option

Specify the policy on placement of a left curly brace ('{').

Constructor Detail

LeftCurlyCheck

public LeftCurlyCheck()

Method Detail

setOption

public void setOption(java.lang.String optionStr)

Setter to specify the policy on placement of a left curly brace ('{').

Parameters:

optionStr - string to decode option from

Throws:

java.lang.IllegalArgumentException - if unable to decode

setIgnoreEnums

public void setIgnoreEnums(boolean ignoreEnums)

Setter to allow to ignore enums when left curly brace policy is EOL.

Parameters:

ignoreEnums - check's option for ignoring enums.

getDefaultTokens

public int[] getDefaultTokens()

Description copied from class: AbstractCheck

Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.

Specified by:

getDefaultTokens in class AbstractCheck

Returns:

the default tokens

See Also:

TokenTypes

getAcceptableTokens

public int[] getAcceptableTokens()

Description copied from class: AbstractCheck

The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.

Specified by:

getAcceptableTokens in class AbstractCheck

Returns:

the token set this check is designed for.

See Also:

TokenTypes

getRequiredTokens

public int[] getRequiredTokens()

Description copied from class: AbstractCheck

The tokens that this check must be registered for.

Specified by:

getRequiredTokens in class AbstractCheck

Returns:

the token set this must be registered for.

See Also:

TokenTypes

visitToken

public void visitToken(DetailAST ast)

We cannot reduce the number of branches in this switch statement, since many tokens require specific methods to find the first left curly.

Overrides:

visitToken in class AbstractCheck

Parameters:

ast - the token to process

getBraceFromSwitchMember

private static DetailAST getBraceFromSwitchMember(DetailAST ast)

Gets the brace of a switch statement/ expression member.

Parameters:

ast - DetailAST.

Returns:

DetailAST if the first child is TokenTypes.SLIST, null otherwise.

getBraceAsFirstChild

private static DetailAST getBraceAsFirstChild(DetailAST ast)

Gets a SLIST if it is the first child of the AST.

Parameters:

ast - DetailAST.

Returns:

DetailAST if the first child is TokenTypes.SLIST, null otherwise.

skipModifierAnnotations

private static DetailAST skipModifierAnnotations(DetailAST ast)

Skip all TokenTypes.ANNOTATIONs to the first non-annotation.

Parameters:

ast - DetailAST.

Returns:

DetailAST.

findLastAnnotation

private static DetailAST findLastAnnotation(DetailAST modifiers)

Find the last token of type TokenTypes.ANNOTATION under the given set of modifiers.

Parameters:

modifiers - DetailAST.

Returns:

DetailAST or null if there are no annotations.

verifyBrace

private void verifyBrace(DetailAST brace,
                         DetailAST startToken)

Verifies that a specified left curly brace is placed correctly according to policy.

Parameters:

brace - token for left curly brace

startToken - token for start of expression

validateEol

private void validateEol(DetailAST brace,
                         java.lang.String braceLine)

Validate EOL case.

Parameters:

brace - brace AST

braceLine - line content

validateNewLinePosition

private void validateNewLinePosition(DetailAST brace,
                                     DetailAST startToken,
                                     java.lang.String braceLine)

Validate token on new Line position.

Parameters:

brace - brace AST

startToken - start Token

braceLine - content of line with Brace

hasLineBreakAfter

private boolean hasLineBreakAfter(DetailAST leftCurly)

Checks if left curly has line break after.

Parameters:

leftCurly - Left curly token.

Returns:

True, left curly has line break after.