rename and improve imported completion computer

pkg/analysis_services/lib/src/completion/imported_type_computer.dart

Index: pkg/analysis_services/lib/src/completion/imported_type_computer.dart
diff --git a/pkg/analysis_services/lib/src/completion/top_level_computer.dart b/pkg/analysis_services/lib/src/completion/imported_type_computer.dart
similarity index 61%
rename from pkg/analysis_services/lib/src/completion/top_level_computer.dart
rename to pkg/analysis_services/lib/src/completion/imported_type_computer.dart
index 536e473776bea44f0408ba9b16fc4e65c540f7a8..8c04570805826078bafaba08129c4050d875c875 100644
--- a/pkg/analysis_services/lib/src/completion/top_level_computer.dart
+++ b/pkg/analysis_services/lib/src/completion/imported_type_computer.dart
@@ -13,15 +13,18 @@ import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 
 /**
- * A computer for calculating class and top level variable
- * `completion.getSuggestions` request results
+ * A computer for calculating imported class and top level variable
+ * `completion.getSuggestions` request results.
  */
-class TopLevelComputer extends CompletionComputer {
+class ImportedTypeComputer extends CompletionComputer {
 
   @override
   bool computeFast(CompilationUnit unit,
       List<CompletionSuggestion> suggestions) {
     // TODO: implement computeFast
+    // - compute results based upon current search, then replace those results
+    // during the full compute phase
+    // - filter results based upon completion offset
     return false;
   }
 
@@ -31,17 +34,36 @@ class TopLevelComputer extends CompletionComputer {
     var future = searchEngine.searchTopLevelDeclarations('');
     return future.then((List<SearchMatch> matches) {
 
+      // Exclude elements from the local library
+      // which will be included by the LocalComputer
+
       // Compute the set of visible libraries to determine relevance
       var visibleLibraries = new Set<LibraryElement>();
+      var excludedLibraries = new Set<LibraryElement>();
       var unitLibrary = unit.element.library;
-      visibleLibraries.add(unitLibrary);
-      visibleLibraries.addAll(unitLibrary.importedLibraries);
+      excludedLibraries.add(unitLibrary);
+      unitLibrary.importedLibraries.forEach((LibraryElement library) {
+        if (library.isDartCore) {
+          visibleLibraries.add(library);
+        }
+      });
+      unit.directives.forEach((Directive directive) {
+        if (directive is ImportDirective) {
+          LibraryElement library = directive.element.importedLibrary;
+          if (directive.prefix == null) {
+            visibleLibraries.add(library);
+          } else {
+            excludedLibraries.add(library);
+          }
+        }
+      });
 
-      // Compute the set of possible classes and top level variables
+      // Compute the set of possible classes, functions, and top level variables
       matches.forEach((SearchMatch match) {
         if (match.kind == MatchKind.DECLARATION) {
           Element element = match.element;
-          if (element.isPublic || element.library == unitLibrary) {
+          if (element.isPublic &&
+              !excludedLibraries.contains(element.library)) {
             String completion = element.displayName;
             var relevance = visibleLibraries.contains(element.library) ?
                 CompletionRelevance.DEFAULT :