Add Tabs As Indent Option In Auto-Formatter Conf

[Michael2MacDonald]

I would like to be able to use tabs for my indentations. You can set this in the IDE but not for the auto-formatter.

An option in formatter.conf like the editor.tabs.expand=false option that is already in the IDE preferences file would fix this issue.

[per1234]

Hi @Michael2MacDonald. I'm happy to inform you that it is now possible to fully customize the behavior of the Arduino IDE 2.x formatter.

There are two different ways to define your custom formatter configuration:

Global scope

If you add a .clang-format configuration file to either of the following locations, the Arduino IDE will always use it instead of the Arduino default configuration:

Windows

C:\Users\<username>\.arduinoIDE\

- OR -

C:\Users\<username>\AppData\Local\Arduino15\

Linux

~/.arduinoIDE/

- OR -

~/.arduino15/

macOS

~/.arduinoIDE

- OR -

~/Library/Arduino15/

Sketch scope

If you add a .clang-format configuration file to the root of a sketch, the Arduino IDE will use that configuration when formatting that sketch. This file has precedence over a global formatter configuration file.

---

If you prefer tabs as indents, you can set that via the UseTab configuration option:

https://releases.llvm.org/14.0.0/tools/clang/docs/ClangFormatStyleOptions.html#:~:text=UseTab%20(UseTabStyle)

Here is Arduino's default configuration in case you would like to use it as a base for your custom configuration:

---
Language: Cpp
# LLVM is the default style setting, used when a configuration option is not set here
BasedOnStyle: LLVM
AccessModifierOffset: -2
AlignAfterOpenBracket: Align
AlignConsecutiveAssignments: false
AlignConsecutiveBitFields: false
AlignConsecutiveDeclarations: false
AlignConsecutiveMacros: false
AlignEscapedNewlines: DontAlign
AlignOperands: Align
AlignTrailingComments: true
AllowAllArgumentsOnNextLine: true
AllowAllConstructorInitializersOnNextLine: true
AllowAllParametersOfDeclarationOnNextLine: true
AllowShortBlocksOnASingleLine: Always
AllowShortCaseLabelsOnASingleLine: true
AllowShortEnumsOnASingleLine: true
AllowShortFunctionsOnASingleLine: Empty
AllowShortIfStatementsOnASingleLine: Always
AllowShortLambdasOnASingleLine: Empty
AllowShortLoopsOnASingleLine: true
AlwaysBreakAfterDefinitionReturnType: None
AlwaysBreakAfterReturnType: None
AlwaysBreakBeforeMultilineStrings: false
AlwaysBreakTemplateDeclarations: No
BinPackArguments: true
BinPackParameters: true
# Only used when "BreakBeforeBraces" set to "Custom"
BraceWrapping:
  AfterCaseLabel: false
  AfterClass: false
  AfterControlStatement: Never
  AfterEnum: false
  AfterFunction: false
  AfterNamespace: false
  #AfterObjCDeclaration:
  AfterStruct: false
  AfterUnion: false
  AfterExternBlock: false
  BeforeCatch: false
  BeforeElse: false
  BeforeLambdaBody: false
  BeforeWhile: false
  IndentBraces: false
  SplitEmptyFunction: false
  SplitEmptyRecord: false
  SplitEmptyNamespace: false
# Java-specific
#BreakAfterJavaFieldAnnotations:
BreakBeforeBinaryOperators: NonAssignment
BreakBeforeBraces: Attach
BreakBeforeTernaryOperators: true
BreakConstructorInitializers: BeforeColon
BreakInheritanceList: BeforeColon
BreakStringLiterals: false
ColumnLimit: 0
# "" matches none
CommentPragmas: ""
CompactNamespaces: false
ConstructorInitializerAllOnOneLineOrOnePerLine: true
ConstructorInitializerIndentWidth: 2
ContinuationIndentWidth: 2
Cpp11BracedListStyle: false
DeriveLineEnding: true
DerivePointerAlignment: true
DisableFormat: false
# Docs say "Do not use this in config files". The default (LLVM 11.0.1) is "false".
#ExperimentalAutoDetectBinPacking:
FixNamespaceComments: false
ForEachMacros: []
IncludeBlocks: Preserve
IncludeCategories: []
# "" matches none
IncludeIsMainRegex: ""
IncludeIsMainSourceRegex: ""
IndentCaseBlocks: true
IndentCaseLabels: true
IndentExternBlock: Indent
IndentGotoLabels: false
IndentPPDirectives: None
IndentWidth: 2
IndentWrappedFunctionNames: false
InsertTrailingCommas: None
# Java-specific
#JavaImportGroups:
# JavaScript-specific
#JavaScriptQuotes:
#JavaScriptWrapImports
KeepEmptyLinesAtTheStartOfBlocks: true
MacroBlockBegin: ""
MacroBlockEnd: ""
# Set to a large number to effectively disable
MaxEmptyLinesToKeep: 100000
NamespaceIndentation: None
NamespaceMacros: []
# Objective C-specific
#ObjCBinPackProtocolList:
#ObjCBlockIndentWidth:
#ObjCBreakBeforeNestedBlockParam:
#ObjCSpaceAfterProperty:
#ObjCSpaceBeforeProtocolList
PenaltyBreakAssignment: 1
PenaltyBreakBeforeFirstCallParameter: 1
PenaltyBreakComment: 1
PenaltyBreakFirstLessLess: 1
PenaltyBreakString: 1
PenaltyBreakTemplateDeclaration: 1
PenaltyExcessCharacter: 1
PenaltyReturnTypeOnItsOwnLine: 1
# Used as a fallback if alignment style can't be detected from code (DerivePointerAlignment: true)
PointerAlignment: Right
RawStringFormats: []
ReflowComments: false
SortIncludes: false
SortUsingDeclarations: false
SpaceAfterCStyleCast: false
SpaceAfterLogicalNot: false
SpaceAfterTemplateKeyword: false
SpaceBeforeAssignmentOperators: true
SpaceBeforeCpp11BracedList: false
SpaceBeforeCtorInitializerColon: true
SpaceBeforeInheritanceColon: true
SpaceBeforeParens: ControlStatements
SpaceBeforeRangeBasedForLoopColon: true
SpaceBeforeSquareBrackets: false
SpaceInEmptyBlock: false
SpaceInEmptyParentheses: false
SpacesBeforeTrailingComments: 2
SpacesInAngles: false
SpacesInCStyleCastParentheses: false
SpacesInConditionalStatement: false
SpacesInContainerLiterals: false
SpacesInParentheses: false
SpacesInSquareBrackets: false
Standard: Auto
StatementMacros: []
TabWidth: 2
TypenameMacros: []
# Default to LF if line endings can't be detected from the content (DeriveLineEnding).
UseCRLF: false
UseTab: Never
WhitespaceSensitiveMacros: []

---

If you would like to try it now, the support for the global scope configuration file (we have had support for the sketch scope configuration file for quite some time already) is in the tester builds available for download under the "Artifacts" section of this page:

https://github.com/arduino/arduino-ide/actions/runs/2455017636#artifacts

It will also be part of tomorrow's nightly build, which will be downloadable from the links here:

https://github.com/arduino/arduino-ide#nightly-builds

Otherwise, it will be in the next release.