"Blank lines after class header" option supported

idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt

@@ -17,10 +17,12 @@
 package org.jetbrains.kotlin.idea.formatter
 
 import com.intellij.formatting.ASTBlock
+import com.intellij.formatting.DependentSpacingRule
 import com.intellij.formatting.Spacing
 import com.intellij.formatting.SpacingBuilder
 import com.intellij.formatting.SpacingBuilder.RuleBuilder
 import com.intellij.lang.ASTNode
+import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiWhiteSpace
 import com.intellij.psi.codeStyle.CodeStyleSettings
 import com.intellij.psi.tree.IElementType
@@ -32,6 +34,7 @@ import org.jetbrains.kotlin.idea.formatter.KotlinSpacingBuilder.CustomSpacingBui
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.lexer.KtTokens.*
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.isObjectLiteral
 import org.jetbrains.kotlin.psi.psiUtil.textRangeWithoutComments
 
 val MODIFIERS_LIST_ENTRIES = TokenSet.orSet(TokenSet.create(ANNOTATION_ENTRY, ANNOTATION), MODIFIER_KEYWORDS)
@@ -78,6 +81,25 @@ fun createSpacingBuilder(settings: CodeStyleSettings, builderUtil: KotlinSpacing
                 } else null
             }
 
+            inPosition(parent = CLASS_BODY, left = LBRACE).customRule { parent, left, right ->
+                if (right.node.elementType == RBRACE) {
+                    return@customRule createSpacing(0)
+                }
+                val classBody = parent.node.psi as KtClassBody
+                val parentPsi = classBody.parent as? KtClassOrObject ?: return@customRule null
+                if (commonCodeStyleSettings.BLANK_LINES_AFTER_CLASS_HEADER == 0 || parentPsi.isObjectLiteral()) {
+                    null
+                }
+                else {
+                    Spacing.createDependentLFSpacing(
+                            0, 0,
+                            TextRange(parentPsi.textRange.startOffset, left.node.psi.textRange.startOffset),
+                            settings.KEEP_LINE_BREAKS, settings.KEEP_BLANK_LINES_IN_DECLARATIONS,
+                            DependentSpacingRule(DependentSpacingRule.Trigger.HAS_LINE_FEEDS)
+                                .registerData(DependentSpacingRule.Anchor.MIN_LINE_FEEDS, commonCodeStyleSettings.BLANK_LINES_AFTER_CLASS_HEADER + 1))
+                }
+            }
+
             val parameterWithDocCommentRule = {
                 _: ASTBlock, _: ASTBlock, right: ASTBlock ->
                 if (right.node.firstChildNode.elementType == KtTokens.DOC_COMMENT) {
@@ -130,8 +152,6 @@ fun createSpacingBuilder(settings: CodeStyleSettings, builderUtil: KotlinSpacing
             after(DOC_COMMENT).lineBreakInCode()
 
             // =============== Spacing ================
-            betweenInside(LBRACE, RBRACE, CLASS_BODY).spaces(0)
-
             before(COMMA).spaceIf(kotlinCommonSettings.SPACE_BEFORE_COMMA)
             after(COMMA).spaceIf(kotlinCommonSettings.SPACE_AFTER_COMMA)
 

idea/src/org/jetbrains/kotlin/idea/formatter/KotlinLanguageCodeStyleSettingsProvider.kt

@@ -252,7 +252,8 @@ class KotlinLanguageCodeStyleSettingsProvider : LanguageCodeStyleSettingsProvide
             LanguageCodeStyleSettingsProvider.SettingsType.BLANK_LINES_SETTINGS -> {
                 consumer.showStandardOptions(
                         "KEEP_BLANK_LINES_IN_CODE",
-                        "KEEP_BLANK_LINES_IN_DECLARATIONS"
+                        "KEEP_BLANK_LINES_IN_DECLARATIONS",
+                        "BLANK_LINES_AFTER_CLASS_HEADER"
                 )
                 showCustomOption(KotlinCodeStyleSettings::BLANK_LINES_AROUND_BLOCK_WHEN_BRANCHES,
                                  "Around 'when' branches with {}",

idea/testData/formatter/BlankLinesAfterClassHeader.after.kt

@@ -0,0 +1,28 @@
+class Foo {
+    fun bar() {
+    }
+}
+
+object Bar {
+    fun xyzzy() {
+    }
+}
+
+val f = object {
+    fun foo() {}
+}
+
+class FooM
+    : IFoo {
+
+    fun bar()
+}
+
+class FooC(
+        val x: String
+) {
+
+    fun bar()
+}
+
+// SET_INT: BLANK_LINES_AFTER_CLASS_HEADER = 1

idea/testData/formatter/BlankLinesAfterClassHeader.kt

@@ -0,0 +1,26 @@
+class Foo {
+    fun bar() {
+    }
+}
+
+object Bar {
+    fun xyzzy() {
+    }
+}
+
+val f = object {
+    fun foo() {}
+}
+
+class FooM
+    : IFoo {
+    fun bar()
+}
+
+class FooC(
+        val x: String
+) {
+    fun bar()
+}
+
+// SET_INT: BLANK_LINES_AFTER_CLASS_HEADER = 1

idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java

@@ -92,6 +92,12 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
             doTest(fileName);
         }
 
+        @TestMetadata("BlankLinesAfterClassHeader.after.kt")
+        public void testBlankLinesAfterClassHeader() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/BlankLinesAfterClassHeader.after.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("BlockFor.after.kt")
         public void testBlockFor() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/formatter/BlockFor.after.kt");