Port a missed piece to remove invalid reference to analysis_server

pkg/analyzer_plugin/lib/src/utilities/completion/element_suggestion_builder.dart

Index: pkg/analyzer_plugin/lib/src/utilities/completion/element_suggestion_builder.dart
diff --git a/pkg/analyzer_plugin/lib/src/utilities/completion/element_suggestion_builder.dart b/pkg/analyzer_plugin/lib/src/utilities/completion/element_suggestion_builder.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f45ec278417973d200d0dd451fa35db9257b7353
--- /dev/null
+++ b/pkg/analyzer_plugin/lib/src/utilities/completion/element_suggestion_builder.dart
@@ -0,0 +1,114 @@
+// Copyright (c) 2017, 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.
+
+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';
+import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer_plugin/src/utilities/completion/suggestion_builder.dart';
+
+/**
+ * Common mixin for sharing behavior.
+ */
+abstract class ElementSuggestionBuilder {
+  // Copied from analysis_server/lib/src/services/completion/dart/suggestion_builder.dart
+  /**
+   * 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;
+
+  /**
+   * Return the resource provider used to access the file system.
+   */
+  ResourceProvider get resourceProvider;
+
+  /**
+   * 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;
+      }
+    }
+    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;
+    }
+    SuggestionBuilderImpl builder = new SuggestionBuilderImpl(resourceProvider);
+    CompletionSuggestion suggestion = builder.forElement(element,
+        completion: completion, kind: kind, relevance: relevance);
+    if (suggestion != null) {
+      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];
+
+          // 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);
+      }
+    }
+  }
+}