Allow user to find usages of overriden methods

idea/src/org/jetbrains/jet/plugin/JetBundle.properties

@@ -264,4 +264,5 @@ there.are.unused.methods.that.override.methods.you.delete=There are unused membe
 choose.the.ones.you.want.to.be.deleted=Choose the ones you want to be deleted.
 method.column=Member
 delete.param.in.method.hierarchy={0} is a part of method hierarchy. Do you want to delete multiple parameters?
-super.methods.delete.with.usage.search=delete (with usage search)
+super.methods.delete.with.usage.search=delete (with usage search)
+super.methods.action.key.find.usages=find usages of

idea/src/org/jetbrains/jet/plugin/findUsages/KotlinFindUsagesHandlerFactory.java

@@ -21,10 +21,13 @@ import com.intellij.find.findUsages.FindUsagesHandlerFactory;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.psi.JetClass;
-import org.jetbrains.jet.lang.psi.JetFunction;
+import org.jetbrains.jet.lang.psi.JetDeclaration;
 import org.jetbrains.jet.lang.psi.JetNamedFunction;
 import org.jetbrains.jet.plugin.findUsages.handlers.KotlinFindClassUsagesHandler;
 import org.jetbrains.jet.plugin.findUsages.handlers.KotlinFindFunctionUsagesHandler;
+import org.jetbrains.jet.plugin.refactoring.JetRefactoringUtil;
+
+import java.util.Collection;
 
 public class KotlinFindUsagesHandlerFactory extends FindUsagesHandlerFactory {
     @Override
@@ -38,6 +41,16 @@ public class KotlinFindUsagesHandlerFactory extends FindUsagesHandlerFactory {
             return new KotlinFindClassUsagesHandler((JetClass) element, this);
         }
         if (element instanceof JetNamedFunction) {
+            if (!forHighlightUsages) {
+                Collection<? extends PsiElement> methods =
+                        JetRefactoringUtil.checkSuperMethods((JetDeclaration) element, null, "super.methods.action.key.find.usages");
+
+                if (methods == null || methods.isEmpty()) return FindUsagesHandler.NULL_HANDLER;
+                if (methods.size() > 1) {
+                    return new KotlinFindFunctionUsagesHandler((JetNamedFunction) element, methods, this);
+                }
+            }
+            
             return new KotlinFindFunctionUsagesHandler((JetNamedFunction) element, this);
         }
         throw new IllegalArgumentException("unexpected element type: " + element);

idea/src/org/jetbrains/jet/plugin/findUsages/handlers/KotlinFindFunctionUsagesHandler.java

@@ -20,7 +20,17 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.psi.JetNamedFunction;
 import org.jetbrains.jet.plugin.findUsages.KotlinFindUsagesHandlerFactory;
 
+import java.util.Collection;
+
 public class KotlinFindFunctionUsagesHandler extends KotlinFindUsagesHandler<JetNamedFunction> {
+    public KotlinFindFunctionUsagesHandler(
+            @NotNull JetNamedFunction function,
+            @NotNull Collection<? extends PsiElement> elementsToSearch,
+            @NotNull KotlinFindUsagesHandlerFactory factory
+    ) {
+        super(function, elementsToSearch, factory);
+    }
+
     public KotlinFindFunctionUsagesHandler(@NotNull JetNamedFunction function, @NotNull KotlinFindUsagesHandlerFactory factory) {
         super(function, factory);
     }