Added plugin implementation for ExternalAnnotationsProvider to be used in IDE.

idea/src/META-INF/plugin.xml

@@ -8,6 +8,12 @@
 
   <depends optional="true">JUnit</depends>
 
+  <application-components>
+    <component>
+      <implementation-class>org.jetbrains.jet.plugin.extAnnotations.IdeaExternalAnnotationsProvider</implementation-class>
+    </component>
+  </application-components>
+
   <project-components>
       <component>
           <implementation-class>org.jetbrains.jet.plugin.JetStandardLibraryInitializer</implementation-class>

idea/src/org/jetbrains/jet/plugin/extAnnotations/IdeaExternalAnnotationsProvider.java

@@ -0,0 +1,59 @@
+/*
+ * 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.extAnnotations;
+
+import com.intellij.codeInsight.ExternalAnnotationsManager;
+import com.intellij.openapi.components.ApplicationComponent;
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.PsiAnnotation;
+import com.intellij.psi.PsiModifierListOwner;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.java.extAnnotations.ExternalAnnotationsProvider;
+
+/**
+ * This class is copied from IDEA.
+ * This class should be eliminated when Kotlin will depend on IDEA 12.x (KT-2326)
+ * @author Evgeny Gerashchenko
+ * @since 6/26/12
+ */
+@Deprecated
+public class IdeaExternalAnnotationsProvider extends ExternalAnnotationsProvider implements ApplicationComponent {
+    @Override
+    public PsiAnnotation findExternalAnnotation(@NotNull Project project, @NotNull PsiModifierListOwner listOwner, @NotNull String annotationFQN) {
+        return ExternalAnnotationsManager.getInstance(project).findExternalAnnotation(listOwner, annotationFQN);
+    }
+
+    @Override
+    public PsiAnnotation[] findExternalAnnotations(@NotNull Project project, @NotNull PsiModifierListOwner listOwner) {
+        return ExternalAnnotationsManager.getInstance(project).findExternalAnnotations(listOwner);
+    }
+
+    @Override
+    public void initComponent() {
+        ExternalAnnotationsProvider.setInstance(this);
+    }
+
+    @Override
+    public void disposeComponent() {
+    }
+
+    @NotNull
+    @Override
+    public String getComponentName() {
+        return getClass().getName();
+    }
+}