IDEA-26763 Auto-complete Generics on the RHS (now in basic completion as well)

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

@@ -210,6 +210,10 @@ public class JavaCompletionContributor extends CompletionContributor {
       return;
     }
 
+    if (JavaSmartCompletionContributor.IN_TYPE_ARGS.accepts(position)) {
+      new TypeArgumentCompletionProvider(false).addCompletions(parameters, new ProcessingContext(), result);
+    }
+
     final InheritorsHolder inheritors = new InheritorsHolder(position, result);
     if (JavaSmartCompletionContributor.AFTER_NEW.accepts(position)) {
       new JavaInheritorsGetter(ConstructorInsertHandler.BASIC_INSTANCE).generateVariants(parameters, result.getPrefixMatcher(), inheritors);

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

@@ -19,6 +19,7 @@ import com.intellij.codeInsight.*;
 import com.intellij.codeInsight.lookup.*;
 import com.intellij.openapi.util.Key;
 import com.intellij.patterns.ElementPattern;
+import com.intellij.patterns.PsiElementPattern;
 import com.intellij.patterns.PsiJavaPatterns;
 import com.intellij.psi.*;
 import com.intellij.psi.filters.ElementExtractorFilter;
@@ -86,6 +87,8 @@ public class JavaSmartCompletionContributor extends CompletionContributor {
   static final ElementPattern<PsiElement> INSIDE_TYPECAST_EXPRESSION = psiElement().withParent(
     psiElement(PsiReferenceExpression.class).afterLeaf(
       psiElement().withText(")").withParent(PsiTypeCastExpression.class)));
+  static final PsiElementPattern.Capture<PsiElement> IN_TYPE_ARGS =
+    psiElement().inside(psiElement(PsiReferenceParameterList.class));
 
   @Nullable
   private static ElementFilter getReferenceFilter(PsiElement element) {
@@ -283,7 +286,7 @@ public class JavaSmartCompletionContributor extends CompletionContributor {
       }
     });
 
-    extend(CompletionType.SMART, psiElement().inside(psiElement(PsiReferenceParameterList.class)), new TypeArgumentCompletionProvider());
+    extend(CompletionType.SMART, IN_TYPE_ARGS, new TypeArgumentCompletionProvider(true));
 
 
     extend(CompletionType.SMART, AFTER_NEW, new JavaInheritorsGetter(ConstructorInsertHandler.SMART_INSTANCE));

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

@@ -46,6 +46,11 @@ import static com.intellij.patterns.PsiJavaPatterns.psiElement;
 * @author peter
 */
 class TypeArgumentCompletionProvider extends CompletionProvider<CompletionParameters> {
+  private final boolean mySmart;
+
+  TypeArgumentCompletionProvider(boolean smart) {
+    mySmart = smart;
+  }
 
   protected void addCompletions(@NotNull final CompletionParameters parameters, final ProcessingContext processingContext, @NotNull final CompletionResultSet resultSet) {
     final PsiElement context = parameters.getPosition();
@@ -58,10 +63,10 @@ class TypeArgumentCompletionProvider extends CompletionProvider<CompletionParame
       for (ExpectedTypeInfo info : types) {
         PsiType type = info.getType();
         if (type instanceof PsiClassType) {
-          fillExpectedTypeArgs(resultSet, context, pair.first, pair.second, ((PsiClassType)type).resolveGenerics(), info.getTailType());
+          fillExpectedTypeArgs(resultSet, context, pair.first, pair.second, ((PsiClassType)type).resolveGenerics(), mySmart ? info.getTailType() : TailType.NONE);
         }
       }
-    } else {
+    } else if (mySmart) {
       addInheritors(parameters, resultSet, pair.first, pair.second);
     }
   }

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

@@ -0,0 +1,5 @@
+import java.util.HashMap;
+
+public class A {
+  private HashMap<String, String> m = new HashMap<St<caret>>()
+}

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

@@ -0,0 +1,5 @@
+import java.util.HashMap;
+
+public class A {
+  private HashMap<String, String> m = new HashMap<String, String>(<caret>)
+}

java/java-tests/testData/codeInsight/completion/smartType/ExcessiveTail-out.java

@@ -1,5 +1,5 @@
 class HashMap<T,V> {}
 
 public class A {
-  private HashMap<String, String> m = new HashMap<String, String><caret>();
+  private HashMap<String, String> m = new HashMap<String, String>();<caret>
 }

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

@@ -1315,4 +1315,13 @@ public class ListUtils {
     checkResult()
   }
 
+  public void testSuggestAllTypeArguments() {
+    configure()
+    assert 'String, String' == lookup.items[1].lookupString
+    lookup.currentItem = lookup.items[1]
+    type '\n'
+    checkResult()
+
+  }
+
 }