extract InheritedReferenceContributor from imported reference contributor

pkg/analysis_server/lib/src/services/completion/dart/suggestion_builder.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library services.completion.dart.suggestion.builder;
 
 import 'package:analysis_server/src/protocol_server.dart' as protocol;
 import 'package:analysis_server/src/protocol_server.dart'
     hide Element, ElementKind;
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
@@ skipping 91 matching lines @@
 /**
  * Common mixin for sharing behavior
  */
 abstract class ElementSuggestionBuilder {
   /**
    * A collection of completion suggestions.
    */
   final List<CompletionSuggestion> suggestions = <CompletionSuggestion>[];
 
   /**
+   * A set of existing completions used to prevent duplicate suggestions.
+   */
+  final Set<String> _completions = new Set<String>();
+
+  /**
+   * A map of element names to suggestions for synthetic getters and setters.
+   */
+  final Map<String, CompletionSuggestion> _syntheticMap =
+      <String, CompletionSuggestion>{};
+
+  /**
    * Return the library in which the completion is requested.
    */
   LibraryElement get containingLibrary;
 
   /**
    * Return the kind of suggestions that should be built.
    */
   CompletionSuggestionKind get kind;
 
   /**
    * Add a suggestion based upon the given element.
    */
   void addSuggestion(Element element,
       {String prefix, int relevance: DART_RELEVANCE_DEFAULT}) {
     if (element.isPrivate) {
       if (element.library != containingLibrary) {
         return;
       }
     }
-    if (prefix == null && element.isSynthetic) {
-      if ((element is PropertyAccessorElement) ||
-          element is FieldElement && !_isSpecialEnumField(element)) {
-        return;
-      }
-    }
     String completion = element.displayName;
     if (prefix != null && prefix.length > 0) {
       if (completion == null || completion.length <= 0) {
         completion = prefix;
       } else {
         completion = '$prefix.$completion';
       }
     }
     if (completion == null || completion.length <= 0) {
       return;
     }
     CompletionSuggestion suggestion = createSuggestion(element,
         completion: completion, kind: kind, relevance: relevance);
     if (suggestion != null) {
-      suggestions.add(suggestion);
-    }
-  }
+      if (element.isSynthetic && element is PropertyAccessorElement) {
+        String cacheKey;
+        if (element.isGetter) {
+          cacheKey = element.name;
+        }
+        if (element.isSetter) {
+          cacheKey = element.name;
+          cacheKey = cacheKey.substring(0, cacheKey.length - 1);
+        }
+        if (cacheKey != null) {
+          CompletionSuggestion existingSuggestion = _syntheticMap[cacheKey];
 
-  /**
-   * Determine if the given element is one of the synthetic enum accessors
-   * for which we should generate a suggestion.
-   */
-  bool _isSpecialEnumField(FieldElement element) {
-    Element parent = element.enclosingElement;
-    if (parent is ClassElement && parent.isEnum) {
-      if (element.name == 'values') {
-        return true;
+          // Pair getter/setter by updating the existing suggestion
+          if (existingSuggestion != null) {
+            CompletionSuggestion getter =
+                element.isGetter ? suggestion : existingSuggestion;
+            protocol.ElementKind elemKind =
+                element.enclosingElement is ClassElement
+                    ? protocol.ElementKind.FIELD
+                    : protocol.ElementKind.TOP_LEVEL_VARIABLE;
+            existingSuggestion.element = new protocol.Element(
+                elemKind,
+                existingSuggestion.element.name,
+                existingSuggestion.element.flags,
+                location: getter.element.location,
+                typeParameters: getter.element.typeParameters,
+                parameters: null,
+                returnType: getter.returnType);
+            return;
+          }
+
+          // Cache lone getter/setter so that it can be paired
+          _syntheticMap[cacheKey] = suggestion;
+        }
+      }
+      if (_completions.add(suggestion.completion)) {
+        suggestions.add(suggestion);
       }
     }
-    return false;
   }
 }
 
 /**
  * This class visits elements in a library and provides suggestions based upon
  * the visible members in that library.
  */
 class LibraryElementSuggestionBuilder extends GeneralizingElementVisitor
     with ElementSuggestionBuilder {
   final LibraryElement containingLibrary;
@@ skipping 38 matching lines @@
   }
 
   @override
   visitElement(Element element) {
     // ignored
   }
 
   @override
   visitFunctionElement(FunctionElement element) {
     if (!typesOnly) {
-      addSuggestion(element);
+      int relevance = element.library == containingLibrary
+          ? DART_RELEVANCE_LOCAL_FUNCTION
+          : DART_RELEVANCE_DEFAULT;
+      addSuggestion(element, relevance: relevance);
     }
   }
 
   @override
   visitFunctionTypeAliasElement(FunctionTypeAliasElement element) {
     if (!instCreation) {
       addSuggestion(element);
     }
   }
 
   @override
   visitTopLevelVariableElement(TopLevelVariableElement element) {
     if (!typesOnly) {
-      addSuggestion(element);
+      int relevance = element.library == containingLibrary
+          ? DART_RELEVANCE_LOCAL_TOP_LEVEL_VARIABLE
+          : DART_RELEVANCE_DEFAULT;
+      addSuggestion(element, relevance: relevance);
     }
   }
 }