java completion: put type above signature containing that type (IDEA-181329)

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

@@ -621,7 +621,11 @@ public class JavaCompletionSorting {
         @Override
         public boolean shouldLift(LookupElement shorterElement, LookupElement longerElement) {
           Object object = shorterElement.getObject();
-          if (object instanceof PsiClass && longerElement.getObject() instanceof PsiClass) {
+          if (!(object instanceof PsiClass)) return false;
+
+          if (longerElement.getUserData(JavaGenerateMemberCompletionContributor.GENERATE_ELEMENT) != null) return true;
+          
+          if (longerElement.getObject() instanceof PsiClass) {
             PsiClass psiClass = (PsiClass)object;
             PsiFile file = psiClass.getContainingFile();
             if (file != null) {

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

@@ -201,7 +201,8 @@ public class JavaGenerateMemberCompletionContributor {
     }
 
     PsiType type = substitutor.substitute(prototype.getReturnType());
-    String signature = modifiers + (type == null ? "" : type.getPresentableText() + " ") + methodName;
+    String typeAndName = (type == null ? "" : type.getPresentableText() + " ") + methodName;
+    String signature = modifiers + typeAndName;
 
     String parameters = "(" + StringUtil.join(prototype.getParameterList().getParameters(),
                                               p -> getShortParameterName(substitutor, p) + " " + p.getName(),
@@ -209,6 +210,7 @@ public class JavaGenerateMemberCompletionContributor {
 
     String overrideSignature = " @Override " + signature; // leading space to make it a middle match, under all annotation suggestions
     LookupElementBuilder element = LookupElementBuilder.create(prototype, signature).withLookupString(methodName).
+      withLookupString(typeAndName).
       withLookupString(signature).withLookupString(overrideSignature).withInsertHandler(insertHandler).
       appendTailText(parameters, false).appendTailText(" {...}", true).withTypeText(typeText).withIcon(icon);
     if (prototype.isDeprecated()) {

java/java-tests/testData/codeInsight/completion/normalSorting/PreferTypeToGeneratedMethod.java

@@ -0,0 +1,4 @@
+class Foo {
+  private String zoo;
+  public Stri<caret>
+}

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

@@ -824,4 +824,8 @@ class Foo {
     myFixture.assertPreferredCompletionItems 0, 'out', 'exit'    
   }
 
+  void testPreferTypeToGeneratedMethod() {
+    checkPreferredItems 0, 'String', 'public String getZoo', 'public String toString'
+  }
+
 }

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

@@ -1662,14 +1662,14 @@ class Bar {
     
     myFixture.configureByText('a.java', 'class Fooxxxxxxxxxx { Fooxxxxx<caret>a f;\n' + 'public void foo() {}\n' * 10000 + '}')
     def items = myFixture.completeBasic()
-    PsiClass c1 = items[0].object
+    PsiClass c1 = items[1].object
     assert !c1.physical
     assert CompletionUtil.getOriginalElement(c1)
     
     getLookup().hide()
     myFixture.type('x')
     items = myFixture.completeBasic()
-    PsiClass c2 = items[0].object
+    PsiClass c2 = items[1].object
     assert !c2.physical
     assert CompletionUtil.getOriginalElement(c2)