Add quick fix for adding @JvmDefault annotation

idea/src/org/jetbrains/kotlin/idea/quickfix/AddJvmDefaultAnnotation.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.quickfix
+
+import com.intellij.codeInsight.intention.IntentionAction
+import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.diagnostics.Diagnostic
+import org.jetbrains.kotlin.idea.util.addAnnotation
+import org.jetbrains.kotlin.psi.KtCallableDeclaration
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtNamedFunction
+import org.jetbrains.kotlin.psi.KtProperty
+import org.jetbrains.kotlin.resolve.annotations.JVM_DEFAULT_FQ_NAME
+
+class AddJvmDefaultAnnotation(declaration: KtCallableDeclaration) : KotlinQuickFixAction<KtCallableDeclaration>(declaration) {
+    override fun getText(): String = "Add '@JvmDefault' annotation"
+
+    override fun getFamilyName(): String = text
+
+    override fun invoke(project: Project, editor: Editor?, file: KtFile) {
+        element?.addAnnotation(JVM_DEFAULT_FQ_NAME)
+    }
+
+    companion object : KotlinSingleIntentionActionFactory() {
+        override fun createAction(diagnostic: Diagnostic): IntentionAction? {
+            val psiElement = diagnostic.psiElement
+            if (psiElement is KtNamedFunction || psiElement is KtProperty)
+                return AddJvmDefaultAnnotation(psiElement as KtCallableDeclaration)
+            return null
+        }
+    }
+}

idea/src/org/jetbrains/kotlin/idea/quickfix/QuickFixRegistrar.kt

@@ -519,5 +519,8 @@ class QuickFixRegistrar : QuickFixContributor {
         ASSIGNING_SINGLE_ELEMENT_TO_VARARG_IN_NAMED_FORM_FUNCTION.registerFactory(SurroundWithArrayOfWithSpreadOperatorInFunctionFix)
 
         JAVA_MODULE_DOES_NOT_DEPEND_ON_MODULE.registerFactory(KotlinAddRequiredModuleFix)
+
+        JVM_DEFAULT_REQUIRED_FOR_OVERRIDE.registerFactory(AddJvmDefaultAnnotation)
+        NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT.registerFactory(AddJvmDefaultAnnotation)
     }
 }