Introduce parent class for "find usage" handlers

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

@@ -22,20 +22,23 @@ 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.JetNamedFunction;
+import org.jetbrains.jet.plugin.findUsages.handlers.KotlinFindClassUsagesHandler;
+import org.jetbrains.jet.plugin.findUsages.handlers.KotlinFindFunctionUsagesHandler;
 
 public class KotlinFindUsagesHandlerFactory extends FindUsagesHandlerFactory {
     @Override
     public boolean canFindUsages(@NotNull PsiElement element) {
-        return element instanceof JetClass || element instanceof JetFunction;
+        return element instanceof JetClass || element instanceof JetNamedFunction;
     }
 
     @Override
     public FindUsagesHandler createFindUsagesHandler(@NotNull PsiElement element, boolean forHighlightUsages) {
         if (element instanceof JetClass) {
-            return new KotlinFindClassUsagesHandler(element);
+            return new KotlinFindClassUsagesHandler((JetClass) element, this);
         }
-        if (element instanceof JetFunction) {
-            return new KotlinFindFunctionUsagesHandler(element);
+        if (element instanceof JetNamedFunction) {
+            return new KotlinFindFunctionUsagesHandler((JetNamedFunction) element, this);
         }
         throw new IllegalArgumentException("unexpected element type: " + element);
     }

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

@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-package org.jetbrains.jet.plugin.findUsages;
+package org.jetbrains.jet.plugin.findUsages.handlers;
 
-import com.intellij.find.findUsages.FindUsagesHandler;
-import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.psi.JetClass;
+import org.jetbrains.jet.plugin.findUsages.KotlinFindUsagesHandlerFactory;
 
-public class KotlinFindClassUsagesHandler extends FindUsagesHandler {
-    public KotlinFindClassUsagesHandler(@NotNull PsiElement psiElement) {
-        super(psiElement);
+public class KotlinFindClassUsagesHandler extends KotlinFindUsagesHandler<JetClass> {
+    public KotlinFindClassUsagesHandler(@NotNull JetClass jetClass, @NotNull KotlinFindUsagesHandlerFactory factory) {
+        super(jetClass, factory);
     }
 }

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

@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-package org.jetbrains.jet.plugin.findUsages;
+package org.jetbrains.jet.plugin.findUsages.handlers;
 
-import com.intellij.find.findUsages.FindUsagesHandler;
-import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.psi.JetNamedFunction;
+import org.jetbrains.jet.plugin.findUsages.KotlinFindUsagesHandlerFactory;
 
-public class KotlinFindFunctionUsagesHandler extends FindUsagesHandler {
-    protected KotlinFindFunctionUsagesHandler(@NotNull PsiElement psiElement) {
-        super(psiElement);
+public class KotlinFindFunctionUsagesHandler extends KotlinFindUsagesHandler<JetNamedFunction> {
+    public KotlinFindFunctionUsagesHandler(@NotNull JetNamedFunction function, @NotNull KotlinFindUsagesHandlerFactory factory) {
+        super(function, factory);
     }
 }

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

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2010-2013 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.findUsages.handlers;
+
+import com.intellij.find.findUsages.FindUsagesHandler;
+import com.intellij.find.findUsages.JavaFindUsagesHandlerFactory;
+import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.plugin.findUsages.KotlinFindUsagesHandlerFactory;
+
+import java.util.Collection;
+import java.util.Collections;
+
+public abstract class KotlinFindUsagesHandler<T extends PsiElement> extends FindUsagesHandler {
+    private final KotlinFindUsagesHandlerFactory factory;
+    private final Collection<? extends PsiElement> elementsToSearch;
+
+    public KotlinFindUsagesHandler(
+            @NotNull T psiElement,
+            @NotNull Collection<? extends PsiElement> elementsToSearch,
+            @NotNull KotlinFindUsagesHandlerFactory factory
+    ) {
+        super(psiElement);
+        this.factory = factory;
+        this.elementsToSearch = elementsToSearch;
+    }
+
+    @SuppressWarnings("unchecked")
+    @NotNull
+    public T getElement() {
+        return (T)getPsiElement();
+    }
+
+    public KotlinFindUsagesHandler(@NotNull T psiElement, @NotNull KotlinFindUsagesHandlerFactory factory) {
+        this(psiElement, Collections.<PsiElement>emptyList(), factory);
+    }
+
+    public final KotlinFindUsagesHandlerFactory getFactory() {
+        return factory;
+    }
+
+    @NotNull
+    @Override
+    public PsiElement[] getPrimaryElements() {
+        return elementsToSearch.isEmpty()
+               ? new PsiElement[] {getPsiElement()}
+               : elementsToSearch.toArray(new PsiElement[elementsToSearch.size()]);
+    }
+}