java sealed types: completion for sealed/non-sealed/permits keywords

GitOrigin-RevId: f689d6f04cd86947ce084f9a0b0f1787f81cf694

java/java-impl/src/com/intellij/codeInsight/completion/JavaKeywordCompletion.java

@@ -602,6 +602,9 @@ public class JavaKeywordCompletion {
       if (!psiClass.isInterface()) {
         addKeyword(new OverridableSpace(createKeyword(PsiKeyword.IMPLEMENTS), TailType.HUMBLE_SPACE_BEFORE_WORD));
       }
+      if (psiClass.hasModifierProperty(PsiModifier.SEALED)) {
+        addKeyword(new OverridableSpace(createKeyword(PsiKeyword.PERMITS), TailType.HUMBLE_SPACE_BEFORE_WORD));
+      }
     }
   }
 

java/java-impl/src/com/intellij/codeInsight/completion/ModifierChooser.java

@@ -1,6 +1,7 @@
 // Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.codeInsight.completion;
 
+import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.filters.FilterPositionUtil;
 import com.intellij.psi.impl.source.jsp.jspJava.JspClassLevelDeclarationStatement;
@@ -20,6 +21,13 @@ public class ModifierChooser {
     {PsiKeyword.PUBLIC},
     {PsiKeyword.FINAL, PsiKeyword.ABSTRACT}
   };
+
+  private static final String[][] CLASS_15_MODIFIERS = {
+    {PsiKeyword.PUBLIC},
+    {PsiKeyword.FINAL, PsiKeyword.ABSTRACT},
+    {PsiKeyword.FINAL, PsiKeyword.SEALED, PsiKeyword.NON_SEALED}
+  };
+
   private static final String[][] CLASS_MEMBER_MODIFIERS = {
     {PsiKeyword.PUBLIC, PsiKeyword.PROTECTED, PsiKeyword.PRIVATE},
     {PsiKeyword.STATIC},
@@ -57,7 +65,7 @@ public class ModifierChooser {
     PsiElement scope = position.getParent();
     while (scope != null) {
       if (scope instanceof PsiJavaFile) {
-        return addClassModifiers(list);
+        return addClassModifiers(list, scope);
       }
       if (scope instanceof PsiClass) {
         return addMemberModifiers(list, ((PsiClass)scope).isInterface(), scope);
@@ -69,8 +77,8 @@ public class ModifierChooser {
     return ArrayUtilRt.EMPTY_STRING_ARRAY;
   }
 
-  public static String[] addClassModifiers(PsiModifierList list) {
-    return addKeywords(list, CLASS_MODIFIERS);
+  public static String[] addClassModifiers(PsiModifierList list, @NotNull PsiElement scope) {
+    return addKeywords(list, PsiUtil.getLanguageLevel(scope).isAtLeast(LanguageLevel.JDK_15_PREVIEW) ? CLASS_15_MODIFIERS : CLASS_MODIFIERS);
   }
 
   public static String[] addMemberModifiers(PsiModifierList list, final boolean inInterface, @NotNull PsiElement position) {

java/java-tests/testData/codeInsight/completion/keywords/permitsList.java

@@ -0,0 +1 @@
+sealed class Foo <caret>{}

java/java-tests/testData/codeInsight/completion/keywords/sealedModifier.java

@@ -0,0 +1 @@
+<caret> class Foo {}

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/KeywordCompletionTest.java

@@ -186,6 +186,8 @@ public class KeywordCompletionTest extends LightCompletionTestCase {
   public void testQualifiedNew() { doTest(1, "new"); }
   public void testRecord() {setLanguageLevel(LanguageLevel.JDK_14_PREVIEW);  doTest(); }
   public void testRecordInFileScope() {setLanguageLevel(LanguageLevel.JDK_14_PREVIEW);  doTest(1, "record"); }
+  public void testSealedModifier() {setLanguageLevel(LanguageLevel.JDK_15_PREVIEW);  doTest(1, "sealed"); }
+  public void testPermitsList() {setLanguageLevel(LanguageLevel.JDK_15_PREVIEW);  doTest(1, "permits"); }
 
   public void testOverwriteCatch() {
     configureByTestName();