Kotlin Facet: Add custom settings and configuration extension point

idea/src/META-INF/extensions/common.xml

@@ -34,5 +34,7 @@
         <extensionPoint name="scriptTemplatesProvider"
                         interface="org.jetbrains.kotlin.script.ScriptTemplatesProvider"
                         area="IDEA_PROJECT"/>
+        <extensionPoint name="facetConfigurationExtension"
+                        interface="org.jetbrains.kotlin.idea.facet.KotlinFacetConfigurationExtension"/>
     </extensionPoints>
 </idea-plugin>

idea/src/org/jetbrains/kotlin/idea/facet/KotlinFacetConfiguration.kt

@@ -21,8 +21,10 @@ import com.intellij.facet.ui.FacetEditorContext
 import com.intellij.facet.ui.FacetEditorTab
 import com.intellij.facet.ui.FacetValidatorsManager
 import com.intellij.openapi.components.PersistentStateComponent
+import com.intellij.openapi.util.Key
 import org.jdom.Element
 import org.jetbrains.kotlin.idea.util.DescriptionAware
+import java.util.*
 
 class KotlinFacetConfiguration : FacetConfiguration, PersistentStateComponent<KotlinFacetConfiguration.Settings> {
     enum class LanguageLevel(override val description: String) : DescriptionAware {
@@ -62,5 +64,9 @@ class KotlinFacetConfiguration : FacetConfiguration, PersistentStateComponent<Ko
     override fun createEditorTabs(
             editorContext: FacetEditorContext,
             validatorsManager: FacetValidatorsManager
-    ): Array<FacetEditorTab> = arrayOf(KotlinFacetEditorTab(this, editorContext, validatorsManager))
+    ): Array<FacetEditorTab> {
+        val tabs = arrayListOf<FacetEditorTab>(KotlinFacetEditorTab(this, editorContext, validatorsManager))
+        KotlinFacetConfigurationExtension.EP_NAME.extensions.flatMapTo(tabs) { it.createEditorTabs(editorContext, validatorsManager) }
+        return tabs.toTypedArray()
+    }
 }

idea/src/org/jetbrains/kotlin/idea/facet/KotlinFacetConfigurationExtension.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2010-2016 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.facet
+
+import com.intellij.facet.ui.FacetEditorContext
+import com.intellij.facet.ui.FacetEditorTab
+import com.intellij.facet.ui.FacetValidatorsManager
+import com.intellij.openapi.extensions.ExtensionPointName
+
+interface KotlinFacetConfigurationExtension {
+    companion object {
+        val EP_NAME: ExtensionPointName<KotlinFacetConfigurationExtension> = ExtensionPointName.create("org.jetbrains.kotlin.facetConfigurationExtension")!!
+    }
+
+    fun createEditorTabs(editorContext: FacetEditorContext, validatorsManager: FacetValidatorsManager): List<FacetEditorTab>
+}

idea/src/org/jetbrains/kotlin/idea/facet/KotlinFacetEditorTab.kt

@@ -146,7 +146,7 @@ class KotlinFacetEditorTab(
         configuration.state.targetPlatformKind = targetPlatformComboBox.selectedItem as KotlinFacetConfiguration.TargetPlatform?
     }
 
-    override fun getDisplayName() = "Kotlin"
+    override fun getDisplayName() = "General"
 
     override fun createComponent(): JComponent {
        val mainPanel = JPanel(BorderLayout())