Show "No SDK configured" annotation for Kotlin files (KT-8634)

#KT-8634 Fixed

idea/src/META-INF/plugin.xml

@@ -515,6 +515,7 @@
 
     <editorNotificationProvider implementation="org.jetbrains.kotlin.idea.versions.UnsupportedAbiVersionNotificationPanelProvider"/>
     <editorNotificationProvider implementation="org.jetbrains.kotlin.idea.highlighter.ErrorDuringFileAnalyzeNotificationProvider"/>
+    <editorNotificationProvider implementation="org.jetbrains.kotlin.idea.configuration.KotlinSetupSDKNotificationProvider"/>
 
     <psi.treeChangePreprocessor implementation="org.jetbrains.kotlin.asJava.KotlinCodeBlockModificationListener"/>
 

idea/src/org/jetbrains/kotlin/idea/configuration/KotlinSetupSDKNotificationProvider.kt

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.configuration
+
+import com.intellij.ProjectTopics
+import com.intellij.openapi.application.runWriteAction
+import com.intellij.openapi.fileEditor.FileEditor
+import com.intellij.openapi.module.ModuleUtilCore
+import com.intellij.openapi.project.DumbAware
+import com.intellij.openapi.project.Project
+import com.intellij.openapi.project.ProjectBundle
+import com.intellij.openapi.roots.ModuleRootAdapter
+import com.intellij.openapi.roots.ModuleRootEvent
+import com.intellij.openapi.roots.ModuleRootManager
+import com.intellij.openapi.roots.ModuleRootModificationUtil
+import com.intellij.openapi.roots.ui.configuration.ProjectSettingsService
+import com.intellij.openapi.util.Key
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.psi.PsiFile
+import com.intellij.psi.PsiManager
+import com.intellij.ui.EditorNotificationPanel
+import com.intellij.ui.EditorNotifications
+import org.jetbrains.kotlin.idea.JetFileType
+import org.jetbrains.kotlin.idea.JetLanguage
+
+// Code is very same to com.intellij.codeInsight.daemon.impl.SetupSDKNotificationProvider
+public class KotlinSetupSDKNotificationProvider(
+        private val myProject: Project,
+        notifications: EditorNotifications) : EditorNotifications.Provider<EditorNotificationPanel>(), DumbAware {
+
+    init {
+        myProject.messageBus.connect(myProject).subscribe(ProjectTopics.PROJECT_ROOTS, object : ModuleRootAdapter() {
+            override fun rootsChanged(event: ModuleRootEvent?) {
+                notifications.updateAllNotifications()
+            }
+        })
+    }
+
+    override fun getKey(): Key<EditorNotificationPanel> = KEY
+
+    override fun createNotificationPanel(file: VirtualFile, fileEditor: FileEditor): EditorNotificationPanel? {
+        if (file.fileType != JetFileType.INSTANCE) {
+            return null
+        }
+
+        val psiFile = PsiManager.getInstance(myProject).findFile(file) ?: return null
+        if (psiFile.language !== JetLanguage.INSTANCE) {
+            return null
+        }
+
+        val module = ModuleUtilCore.findModuleForPsiElement(psiFile) ?: return null
+        if (ModuleRootManager.getInstance(module).sdk != null) {
+            return null
+        }
+
+        return createPanel(myProject, psiFile)
+    }
+
+    companion object {
+        private val KEY = Key.create<EditorNotificationPanel>("Setup SDK")
+
+        private fun createPanel(project: Project, file: PsiFile): EditorNotificationPanel {
+            return EditorNotificationPanel().apply {
+                setText(ProjectBundle.message("project.sdk.not.defined"))
+                createActionLabel(ProjectBundle.message("project.sdk.setup")) {
+                    ProjectSettingsService.getInstance(project).chooseAndSetSdk() ?: return@createActionLabel
+
+                    runWriteAction {
+                        val module = ModuleUtilCore.findModuleForPsiElement(file)
+                        if (module != null) {
+                            ModuleRootModificationUtil.setSdkInherited(module)
+                        }
+                    }
+                }
+            }
+        }
+    }
+}