IDEA-87104 Code completion should remember and prefer chosen variants

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

@@ -52,28 +52,14 @@ public class JavaCompletionStatistician extends CompletionStatistician{
     if (item == null) return null;
 
     PsiType qualifierType = JavaCompletionUtil.getQualifierType(item);
-    if (qualifierType == null) {
-      if (infos != null && infos.length > 0) {
-        qualifierType = infos[0].getDefaultType();
-      }
-    }
 
-    final CompletionType type = location.getCompletionType();
     if (o instanceof PsiMember) {
-      final boolean isClass = o instanceof PsiClass;
-      if (qualifierType != null) {
-        String context;
-        if (isClass) {
-          context = JavaStatisticsManager.getAfterNewKey(qualifierType);
-        } else {
-          context = JavaStatisticsManager.getMemberUseKey1(qualifierType);
-        }
-        return new StatisticsInfo(context, JavaStatisticsManager.getMemberUseKey2((PsiMember)o));
-      }
-
-      if (isClass) {
-        return JavaStatisticsManager.createInfo(qualifierType, (PsiMember)o);
+      String key2 = JavaStatisticsManager.getMemberUseKey2((PsiMember)o);
+      if (o instanceof PsiClass) {
+        PsiType expectedType = infos != null && infos.length > 0 ? infos[0].getDefaultType() : null;
+        return new StatisticsInfo(JavaStatisticsManager.getAfterNewKey(expectedType), key2);
       }
+      return new StatisticsInfo(JavaStatisticsManager.getMemberUseKey2(((PsiMember)o).getContainingClass()), key2);
     }
 
     if (qualifierType != null) return StatisticsInfo.EMPTY;

java/java-psi-api/src/com/intellij/psi/util/TypeConversionUtil.java

@@ -1186,11 +1186,11 @@ public class TypeConversionUtil {
     return PsiType.getJavaLangObject(typeParameter.getManager(), typeParameter.getResolveScope());
   }
 
-  public static PsiType erasure(PsiType type) {
+  public static PsiType erasure(@Nullable PsiType type) {
     return erasure(type, PsiSubstitutor.EMPTY);
   }
 
-  public static PsiType erasure(final PsiType type, final PsiSubstitutor beforeSubstitutor) {
+  public static PsiType erasure(@Nullable final PsiType type, final PsiSubstitutor beforeSubstitutor) {
     if (type == null) return null;
     return type.accept(new PsiTypeVisitor<PsiType>() {
       @Override

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

@@ -0,0 +1,9 @@
+import javax.swing.*;
+
+public class MyFirstTestClassFoo {
+
+  void foo(JComponent c) {
+    c.getCom<caret>x
+  }
+
+}

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

@@ -0,0 +1,9 @@
+import javax.swing.*;
+
+public class MyFirstTestClassFoo {
+
+  void foo(JLabel l) {
+    l.getCompo<caret>x
+  }
+
+}

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

@@ -13,6 +13,7 @@ import com.intellij.codeInsight.lookup.impl.LookupImpl
 import com.intellij.ide.ui.UISettings
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiMethod
+import com.intellij.openapi.fileEditor.FileDocumentManager
 
 public class NormalCompletionOrderingTest extends CompletionSortingTestCase {
   private static final String BASE_PATH = "/codeInsight/completion/normalSorting";
@@ -148,6 +149,32 @@ public class NormalCompletionOrderingTest extends CompletionSortingTestCase {
     assertPreferredItems(0, "FooBee", "FooBar");
   }
 
+  public void testSameStatsForDifferentQualifiers() throws Throwable {
+    invokeCompletion("SameStatsForDifferentQualifiersJLabel.java");
+    assertPreferredItems(0, "getComponent");
+    incUseCount(getLookup(), myFixture.lookupElementStrings.indexOf('getComponents'));
+    FileDocumentManager.instance.saveAllDocuments()
+
+    invokeCompletion("SameStatsForDifferentQualifiersJLabel.java");
+    assertPreferredItems(1, "getComponent", "getComponents");
+
+    invokeCompletion("SameStatsForDifferentQualifiersJComponent.java");
+    assertPreferredItems(1, "getComponent", "getComponents");
+  }
+
+  public void testSameStatsForDifferentQualifiers2() throws Throwable {
+    invokeCompletion("SameStatsForDifferentQualifiersJComponent.java");
+    assertPreferredItems(0, "getComponent");
+    incUseCount(getLookup(), myFixture.lookupElementStrings.indexOf('getComponents'));
+    FileDocumentManager.instance.saveAllDocuments()
+
+    invokeCompletion("SameStatsForDifferentQualifiersJComponent.java");
+    assertPreferredItems(1, "getComponent", "getComponents");
+
+    invokeCompletion("SameStatsForDifferentQualifiersJLabel.java");
+    assertPreferredItems(1, "getComponent", "getComponents");
+  }
+
   public void testDispreferFinalize() throws Throwable {
     checkPreferredItems(0, "final", "finalize");
   }

java/openapi/src/com/intellij/psi/statistics/JavaStatisticsManager.java

@@ -95,7 +95,7 @@ public abstract class JavaStatisticsManager {
   }
 
   @NonNls @NotNull
-  public static String getMemberUseKey1(PsiType qualifierType) {
+  public static String getMemberUseKey1(@Nullable PsiType qualifierType) {
     qualifierType = TypeConversionUtil.erasure(qualifierType);
     return "member#" + (qualifierType == null ? "" : qualifierType.getCanonicalText());
   }
@@ -140,7 +140,7 @@ public abstract class JavaStatisticsManager {
     return ArrayUtil.toStringArray(list);
   }
 
-  public static String getAfterNewKey(PsiType expectedType) {
+  public static String getAfterNewKey(@Nullable PsiType expectedType) {
     return getMemberUseKey1(expectedType) + "###smartAfterNew";
   }