IDEA-65810 Class completion: suggest most probable class in the specific context.

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

@@ -0,0 +1,16 @@
+enum Zoo {
+    A,B,C,D,E,F,G,H
+}
+
+class Zaa {}
+class Zab {}
+class Zac {}
+class Zad {}
+class Zae {}
+
+class Bar {
+
+    {
+        Zoo z = Z<caret>
+    }
+}

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

@@ -205,4 +205,8 @@ public class NormalCompletionOrderingTest extends CompletionSortingTestCase {
     checkPreferredItems(0, "foo", "boo", "doo", "hashCode");
   }
 
+  public void testPreferClassOverItsStaticMembers() {
+    checkPreferredItems(0, "Zoo");
+  }
+
 }

platform/lang-impl/src/com/intellij/codeInsight/completion/PrefixMatchingWeigher.java

@@ -19,6 +19,8 @@ import com.intellij.codeInsight.lookup.LookupElement;
 import com.intellij.openapi.util.text.StringUtil;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Set;
+
 /**
  * @author peter
 */
@@ -31,14 +33,21 @@ public class PrefixMatchingWeigher extends CompletionWeigher {
       return 0;
     }
 
-    final String lookupString = item.getLookupString();
     final String prefixHumps = StringUtil.capitalsOnly(prefix);
-    final String itemHumps = StringUtil.capitalsOnly(lookupString);
+    final Set<String> strings = item.getAllLookupStrings();
+
+    for (String lookupString : strings) {
+      if (StringUtil.capitalsOnly(lookupString).startsWith(prefixHumps)) return 100;
+    }
+
+    for (String lookupString : strings) {
+      if (lookupString.startsWith(prefix)) return 5;
+    }
+    for (String lookupString : strings) {
+      if (StringUtil.startsWithIgnoreCase(lookupString, prefix)) return 1;
+    }
 
-    if (itemHumps.startsWith(prefixHumps)) return 100;// - itemHumps.length();
 
-    if (lookupString.startsWith(prefix)) return 5;
-    if (StringUtil.startsWithIgnoreCase(lookupString, prefix)) return 1;
     return 0;
   }
 }

platform/lang-impl/src/com/intellij/codeInsight/completion/impl/LiftShorterItemsClassifier.java

@@ -93,7 +93,11 @@ class LiftShorterItemsClassifier extends Classifier<LookupElement> {
             for (LookupElement shorterElement : myElements.get(prefix)) {
               if (srcSet.contains(shorterElement) && processed.add(shorterElement)) {
                 lifted.add(shorterElement);
-                group.add(shorterElement);
+                if (group.isEmpty()) {
+                  result.add(Collections.singletonList(shorterElement));
+                } else {
+                  group.add(shorterElement);
+                }
               }
             }
           }