breakpoints for multi-file namespaces

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JetFilesProvider.java

@@ -19,13 +19,20 @@
  */
 package org.jetbrains.jet.lang.resolve.java;
 
+import com.google.common.base.Predicate;
 import com.intellij.openapi.components.ServiceManager;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.UserDataHolder;
+import com.intellij.openapi.util.UserDataHolderBase;
+import com.intellij.psi.PsiFile;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.util.Function;
 import org.jetbrains.jet.lang.psi.JetFile;
+import org.jetbrains.jet.lang.psi.JetPsiUtil;
+import org.jetbrains.jet.lang.resolve.name.FqName;
 
 import java.util.Collection;
+import java.util.LinkedList;
 import java.util.List;
 
 public abstract class JetFilesProvider {
@@ -33,6 +40,37 @@ public abstract class JetFilesProvider {
         return ServiceManager.getService(project, JetFilesProvider.class);
     }
 
+    public final Function<JetFile, List<JetFile>> allNamespaceFiles() {
+        return new Function<JetFile, List<JetFile>>() {
+            @Override
+            public List<JetFile> fun(JetFile file) {
+                return new SameJetFilePredicate(file).filter(sampleToAllFilesInModule().fun(file));
+            }
+        };
+    }
+
     public abstract Function<JetFile, Collection<JetFile>> sampleToAllFilesInModule();
     public abstract List<JetFile> allInScope(GlobalSearchScope scope);
+
+    public static class SameJetFilePredicate implements Predicate<PsiFile> {
+        private final FqName name;
+
+        public SameJetFilePredicate(JetFile file) {
+            this.name = JetPsiUtil.getFQName(file);
+        }
+
+        @Override
+        public boolean apply(PsiFile psiFile) {
+            return JetPsiUtil.getFQName((JetFile) psiFile).equals(name);
+        }
+
+        public List<JetFile> filter(Collection<JetFile> allFiles) {
+            LinkedList<JetFile> files = new LinkedList<JetFile>();
+            for (JetFile aFile : allFiles) {
+                if(apply(aFile))
+                    files.add(aFile);
+            }
+            return files;
+        }
+    }
 }