inheritor navigation works from Java to Kotlin

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClass.java

@@ -207,20 +207,15 @@ private String getQualifiedName() {
      */
     @NotNull
     public List<String> getSuperNames() {
-        final JetDelegationSpecifierList delegationSpecifierList = getDelegationSpecifierList();
-        if (delegationSpecifierList == null) return Collections.emptyList();
-        final List<JetDelegationSpecifier> specifiers = delegationSpecifierList.getDelegationSpecifiers();
+        final List<JetDelegationSpecifier> specifiers = getDelegationSpecifiers();
         if (specifiers.size() == 0) return Collections.emptyList();
         List<String> result = new ArrayList<String>();
         for (JetDelegationSpecifier specifier : specifiers) {
-            final JetTypeReference typeReference = specifier.getTypeReference();
-            if (typeReference != null) {
-                final JetTypeElement typeElement = typeReference.getTypeElement();
-                if (typeElement instanceof JetUserType) {
-                    final String referencedName = ((JetUserType) typeElement).getReferencedName();
-                    if (referencedName != null) {
-                        addSuperName(result, referencedName);
-                    }
+            final JetUserType superType = specifier.getTypeAsUserType();
+            if (superType != null) {
+                final String referencedName = superType.getReferencedName();
+                if (referencedName != null) {
+                    addSuperName(result, referencedName);
                 }
             }
         }

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDelegationSpecifier.java

@@ -43,4 +43,16 @@ public <R, D> R accept(@NotNull JetVisitor<R, D> visitor, D data) {
     public JetTypeReference getTypeReference() {
         return (JetTypeReference) findChildByType(JetNodeTypes.TYPE_REFERENCE);
     }
+
+    @Nullable
+    public JetUserType getTypeAsUserType() {
+        final JetTypeReference reference = getTypeReference();
+        if (reference != null) {
+            final JetTypeElement element = reference.getTypeElement();
+            if (element instanceof JetUserType) {
+                return ((JetUserType) element);
+            }
+        }
+        return null;
+    }
 }

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDelegatorToSuperCall.java

@@ -82,16 +82,8 @@ public List<JetTypeProjection> getTypeArguments() {
 
     @Override
     public JetTypeArgumentList getTypeArgumentList() {
-        JetTypeReference typeReference = getTypeReference();
-        if (typeReference == null) {
-            return null;
-        }
-        JetTypeElement typeElement = typeReference.getTypeElement();
-        if (typeElement instanceof JetUserType) {
-            JetUserType userType = (JetUserType) typeElement;
-            return userType.getTypeArgumentList();
-        }
-        return null;
+        final JetUserType userType = getTypeAsUserType();
+        return userType != null ? userType.getTypeArgumentList() : null;
     }
 
 }

idea/src/META-INF/plugin.xml

@@ -186,6 +186,7 @@
       <psi.treeChangePreprocessor implementation="org.jetbrains.jet.asJava.JetCodeBlockModificationListener"/>
 
       <referencesSearch implementation="org.jetbrains.jet.plugin.references.KotlinReferencesSearcher"/>
+      <directClassInheritorsSearch implementation="org.jetbrains.jet.plugin.references.KotlinDirectInheritorsSearcher"/>
 
       <toolWindow id="Kotlin"
                   factoryClass="org.jetbrains.jet.plugin.internal.KotlinInternalToolWindowFactory"

idea/src/org/jetbrains/jet/plugin/references/KotlinDirectInheritorsSearcher.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2010-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.plugin.references;
+
+import com.intellij.openapi.application.QueryExecutorBase;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiReference;
+import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.psi.search.searches.DirectClassInheritorsSearch;
+import com.intellij.util.Processor;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.asJava.JetLightClass;
+import org.jetbrains.jet.lang.psi.*;
+import org.jetbrains.jet.plugin.stubindex.JetSuperClassIndex;
+
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * @author yole
+ */
+public class KotlinDirectInheritorsSearcher extends QueryExecutorBase<PsiClass, DirectClassInheritorsSearch.SearchParameters> {
+    public KotlinDirectInheritorsSearcher() {
+        super(true);
+    }
+
+    @Override
+    public void processQuery(@NotNull DirectClassInheritorsSearch.SearchParameters queryParameters, @NotNull Processor<PsiClass> consumer) {
+        final PsiClass clazz = queryParameters.getClassToProcess();
+        final String name = clazz.getName();
+        if (name == null || !(queryParameters.getScope() instanceof GlobalSearchScope)) return;
+        GlobalSearchScope scope = (GlobalSearchScope) queryParameters.getScope();
+        final Collection<JetClassOrObject> candidates = JetSuperClassIndex.getInstance().get(name, clazz.getProject(), scope);
+        for (JetClassOrObject candidate : candidates) {
+            if (!(candidate instanceof JetClass)) continue;
+            final List<JetDelegationSpecifier> specifiers = candidate.getDelegationSpecifiers();
+            for (JetDelegationSpecifier specifier : specifiers) {
+                final JetUserType type = specifier.getTypeAsUserType();
+                if (type != null) {
+                    final JetSimpleNameExpression referenceExpression = type.getReferenceExpression();
+                    if (referenceExpression != null) {
+                        final PsiReference reference = referenceExpression.getReference();
+                        final PsiElement resolved = reference != null ? reference.resolve() : null;
+                        if (resolved instanceof PsiClass && resolved.isEquivalentTo(clazz)) {
+                            consumer.process(JetLightClass.wrapDelegate((JetClass) candidate));
+                        }
+                    }
+                }
+            }
+        }
+    }
+}