[java-completion] IDEA-63639 Completion after new offers in list classes with private constructors

GitOrigin-RevId: 141336a239f027b0eb5cc9f2f783f1415eeb5f76

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

@@ -595,6 +595,19 @@ public class JavaCompletionContributor extends CompletionContributor implements
     PsiElement position = parameters.getPosition();
     ElementFilter filter = getReferenceFilter(position);
     if (filter == null) return Collections.emptyList();
+    if (parameters.getInvocationCount() <= 1 && JavaClassNameCompletionContributor.AFTER_NEW.accepts(position)) {
+      filter = new AndFilter(filter, new ElementFilter() {
+        @Override
+        public boolean isAcceptable(Object element, @Nullable PsiElement context) {
+          return !JavaPsiClassReferenceElement.isInaccessibleConstructorSuggestion(position, tryCast(element, PsiClass.class));
+        }
+
+        @Override
+        public boolean isClassAcceptable(Class hintClass) {
+          return true;
+        }
+      });
+    }
 
     boolean smart = parameters.getCompletionType() == CompletionType.SMART;
     if (smart) {

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

@@ -210,11 +210,16 @@ public class JavaNoVariantsDelegator extends CompletionContributor implements Du
         return;
       }
       JavaPsiClassReferenceElement classElement = element.as(JavaPsiClassReferenceElement.CLASS_CONDITION_KEY);
+      PsiElement position = parameters.getPosition();
       if (classElement != null && parameters.getInvocationCount() < 2) {
+        if (JavaClassNameCompletionContributor.AFTER_NEW.accepts(position) &&
+            JavaPsiClassReferenceElement.isInaccessibleConstructorSuggestion(position, classElement.getObject())) {
+          return;
+        }
         classElement.setAutoCompletionPolicy(AutoCompletionPolicy.NEVER_AUTOCOMPLETE);
       }
 
-      element = JavaCompletionUtil.highlightIfNeeded(null, element, element.getObject(), parameters.getPosition());
+      element = JavaCompletionUtil.highlightIfNeeded(null, element, element.getObject(), position);
       if (!sameNamedBatch.isEmpty() && !element.getLookupString().equals(sameNamedBatch.get(0).getLookupString())) {
         result.addAllElements(sameNamedBatch);
         sameNamedBatch.clear();

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

@@ -24,8 +24,10 @@ import com.intellij.openapi.util.ClassConditionKey;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
+import com.intellij.psi.impl.source.resolve.JavaResolveUtil;
 import com.intellij.psi.util.PsiFormatUtil;
 import com.intellij.psi.util.PsiUtilCore;
+import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -221,4 +223,13 @@ public class JavaPsiClassReferenceElement extends LookupItem<Object> implements
     return CodeStyle.getLanguageSettings(element.getContainingFile(), JavaLanguage.INSTANCE).SPACE_AFTER_COMMA;
   }
 
+  static boolean isInaccessibleConstructorSuggestion(@NotNull PsiElement position, @Nullable PsiClass cls) {
+    if (cls == null || cls.hasModifierProperty(PsiModifier.ABSTRACT)) return false;
+    PsiMethod[] constructors = cls.getConstructors();
+    if (constructors.length > 0) {
+      return !ContainerUtil.exists(constructors, ctor ->
+        JavaResolveUtil.isAccessible(ctor, cls, ctor.getModifierList(), position, null, null));
+    }
+    return false;
+  }
 }

java/java-tests/testData/codeInsight/completion/normal/ClassNameWithInnersTab.java

@@ -7,7 +7,7 @@ public class TestClass {
 }
 
 class Xxx {
-    private Xxx(String x) {
+    Xxx(String x) {
     }
 
     static class Yyy {

java/java-tests/testData/codeInsight/completion/normal/ClassNameWithInnersTab_after.java

@@ -7,7 +7,7 @@ public class TestClass {
 }
 
 class Xxx {
-    private Xxx(String x) {
+    Xxx(String x) {
     }
 
     static class Yyy {

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy

@@ -22,6 +22,7 @@ import com.intellij.psi.codeStyle.JavaCodeStyleSettings
 import com.intellij.testFramework.LightProjectDescriptor
 import com.intellij.testFramework.NeedsIndex
 import com.intellij.testFramework.PlatformTestUtil
+import com.intellij.util.containers.ContainerUtil
 import com.intellij.util.ui.UIUtil
 import com.siyeh.ig.style.UnqualifiedFieldAccessInspection
 import groovy.transform.CompileStatic
@@ -2298,4 +2299,11 @@ class Abc {
     assert myFixture.getLookupElementStrings().stream().filter({ it.contains("sss") }).collect(Collectors.toList()) == 
            ["A.sss", "sss"]
   }
+
+  @NeedsIndex.ForStandardLibrary
+  void "test private constructor"() {
+    myFixture.configureByText("A.java", "class A {{new Syst<caret>}}")
+    myFixture.completeBasic()
+    assert ContainerUtil.filter(myFixture.getLookupElementStrings(), {it.startsWith("S")}) == ['System.Logger', 'System.LoggerFinder']
+  }
 }