Add line indentation support to the formatter

Author: waleedyaseen

CHANGELOG.md

@@ -12,6 +12,7 @@
 - Inspections that require symbols will no longer run on files outside the project.
 - Update the file extension for commands from ".op" to ".cs2".
 - Improve the handling and parsing of block comments.
+- Add line indentation support to the formatter.
 
 ## [1.3.0] - 2023-08-30
 

src/main/kotlin/io/runescript/plugin/ide/formatter/lineIndent/RsLineIndentProvider.kt

@@ -0,0 +1,56 @@
+package io.runescript.plugin.ide.formatter.lineIndent
+
+import com.intellij.formatting.Indent
+import com.intellij.lang.Language
+import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.project.Project
+import com.intellij.psi.TokenType
+import com.intellij.psi.impl.source.codeStyle.SemanticEditorPosition
+import com.intellij.psi.impl.source.codeStyle.lineIndent.IndentCalculator
+import com.intellij.psi.impl.source.codeStyle.lineIndent.JavaLikeLangLineIndentProvider
+import com.intellij.psi.impl.source.codeStyle.lineIndent.JavaLikeLangLineIndentProvider.JavaLikeElement.*
+import com.intellij.psi.tree.IElementType
+import io.runescript.plugin.lang.RuneScript
+import io.runescript.plugin.lang.psi.RsElementTypes
+import io.runescript.plugin.lang.psi.RsTokenTypes
+
+class RsLineIndentProvider : JavaLikeLangLineIndentProvider() {
+    override fun mapType(tokenType: IElementType): SemanticEditorPosition.SyntaxElement? {
+        return elementsMap[tokenType]
+    }
+
+    override fun getIndent(project: Project, editor: Editor, language: Language?, offset: Int): IndentCalculator? {
+        val currentPosition = getPosition(editor, offset)
+        val before = currentPosition.beforeOptionalMix(Whitespace, LineComment, BlockComment)
+        val factory = IndentCalculatorFactory(project, editor)
+        if (getPosition(editor, offset).before().isAt(LeftParenthesis)) {
+            return null
+        }
+        return when {
+            before.isAt(Semicolon) -> factory.createIndentCalculator(Indent.getNoneIndent(), IndentCalculator.LINE_BEFORE)
+            before.isAt(BlockOpeningBrace) -> factory.createIndentCalculator(Indent.getNormalIndent()) { before.startOffset }
+            else -> super.getIndent(project, editor, language, offset)
+        }
+    }
+
+    override fun isSuitableForLanguage(language: Language) = language.isKindOf(RuneScript)
+
+    companion object {
+        private val elementsMap: Map<IElementType, SemanticEditorPosition.SyntaxElement> = hashMapOf(
+            TokenType.WHITE_SPACE to Whitespace,
+            RsElementTypes.SEMICOLON to Semicolon,
+            RsElementTypes.LBRACE to BlockOpeningBrace,
+            RsElementTypes.RBRACE to BlockClosingBrace,
+            RsElementTypes.LPAREN to RightParenthesis,
+            RsElementTypes.RPAREN to LeftParenthesis,
+            RsElementTypes.COLON to Colon,
+            RsElementTypes.CASE to SwitchCase,
+            RsElementTypes.DEFAULT to SwitchDefault,
+            RsElementTypes.ELSE to ElseKeyword,
+            RsElementTypes.IF to IfKeyword,
+            RsTokenTypes.MULTI_LINE_COMMENT to BlockComment,
+            RsTokenTypes.SINGLE_LINE_COMMENT to LineComment,
+            RsElementTypes.COMMA to Comma
+        )
+    }
+}

src/main/resources/META-INF/plugin.xml

@@ -57,6 +57,7 @@
         <lang.formatter language="RuneScript" implementationClass="io.runescript.plugin.ide.formatter.RsFormatter"/>
         <codeStyleSettingsProvider implementation="io.runescript.plugin.ide.formatter.style.RsCodeStyleSettingsProvider"/>
         <langCodeStyleSettingsProvider implementation="io.runescript.plugin.ide.formatter.style.RsLanguageCodeStyleSettingsProvider"/>
+        <lineIndentProvider implementation="io.runescript.plugin.ide.formatter.lineIndent.RsLineIndentProvider"/>
 
         <!-- Code Insights -->
         <codeInsight.lineMarkerProvider language="RuneScript" implementationClass="io.runescript.plugin.ide.lineMarker.RsLineMarkerProvider"/>