suggest prefixed constructors - fixes #23210

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

Index: pkg/analysis_server/lib/src/services/completion/suggestion_builder.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/suggestion_builder.dart b/pkg/analysis_server/lib/src/services/completion/suggestion_builder.dart
index c6e376a2c91ab8f453522dda00d922885d6bbed8..a2379acc4128c523e9f859c73451565cbecc2002 100644
--- a/pkg/analysis_server/lib/src/services/completion/suggestion_builder.dart
+++ b/pkg/analysis_server/lib/src/services/completion/suggestion_builder.dart
@@ -25,14 +25,16 @@ const String DYNAMIC = 'dynamic';
  * If the suggestion is not currently in scope, then specify
  * importForSource as the source to which an import should be added.
  */
-CompletionSuggestion createSuggestion(Element element,
-    {CompletionSuggestionKind kind: CompletionSuggestionKind.INVOCATION,
+CompletionSuggestion createSuggestion(Element element, {String completion,
+    CompletionSuggestionKind kind: CompletionSuggestionKind.INVOCATION,
     int relevance: DART_RELEVANCE_DEFAULT, Source importForSource}) {
   if (element is ExecutableElement && element.isOperator) {
     // Do not include operators in suggestions
     return null;
   }
-  String completion = element.displayName;
+  if (completion == null) {
+    completion = element.displayName;
+  }
   bool isDeprecated = element.isDeprecated;
   CompletionSuggestion suggestion = new CompletionSuggestion(kind,
       isDeprecated ? DART_RELEVANCE_LOW : relevance, completion,
@@ -189,7 +191,8 @@ abstract class ElementSuggestionBuilder {
   /**
    * Add a suggestion based upon the given element.
    */
-  void addSuggestion(Element element, {int relevance: DART_RELEVANCE_DEFAULT}) {
+  void addSuggestion(Element element,
+      {String prefix, int relevance: DART_RELEVANCE_DEFAULT}) {
     if (element.isPrivate) {
       LibraryElement elementLibrary = element.library;
       CompilationUnitElement unitElem = request.unit.element;
@@ -201,18 +204,25 @@ abstract class ElementSuggestionBuilder {
         return;
       }
     }
-    if (element.isSynthetic) {
+    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, kind: kind, relevance: relevance);
+    CompletionSuggestion suggestion = createSuggestion(element,
+        completion: completion, kind: kind, relevance: relevance);
     if (suggestion != null) {
       request.addSuggestion(suggestion);
     }
@@ -440,12 +450,18 @@ class LibraryElementSuggestionBuilder extends GeneralizingElementVisitor
   final DartCompletionRequest request;
   final CompletionSuggestionKind kind;
   final bool typesOnly;
+  final bool instCreation;
 
-  LibraryElementSuggestionBuilder(this.request, this.kind, this.typesOnly);
+  LibraryElementSuggestionBuilder(
+      this.request, this.kind, this.typesOnly, this.instCreation);
 
   @override
   visitClassElement(ClassElement element) {
-    addSuggestion(element);
+    if (instCreation) {
+      element.visitChildren(this);
+    } else {
+      addSuggestion(element);
+    }
   }
 
   @override
@@ -460,6 +476,19 @@ class LibraryElementSuggestionBuilder extends GeneralizingElementVisitor
   }
 
   @override
+  visitConstructorElement(ConstructorElement element) {
+    if (instCreation) {
+      ClassElement classElem = element.enclosingElement;
+      if (classElem != null) {
+        String prefix = classElem.name;
+        if (prefix != null && prefix.length > 0) {
+          addSuggestion(element, prefix: prefix);
+        }
+      }
+    }
+  }
+
+  @override
   visitElement(Element element) {
     // ignored
   }
@@ -473,7 +502,9 @@ class LibraryElementSuggestionBuilder extends GeneralizingElementVisitor
 
   @override
   visitFunctionTypeAliasElement(FunctionTypeAliasElement element) {
-    addSuggestion(element);
+    if (!instCreation) {
+      addSuggestion(element);
+    }
   }
 
   @override
@@ -487,10 +518,11 @@ class LibraryElementSuggestionBuilder extends GeneralizingElementVisitor
    * Add suggestions for the visible members in the given library
    */
   static void suggestionsFor(DartCompletionRequest request,
-      CompletionSuggestionKind kind, LibraryElement library, bool typesOnly) {
+      CompletionSuggestionKind kind, LibraryElement library, bool typesOnly,
+      bool instCreation) {
     if (library != null) {
-      library.visitChildren(
-          new LibraryElementSuggestionBuilder(request, kind, typesOnly));
+      library.visitChildren(new LibraryElementSuggestionBuilder(
+          request, kind, typesOnly, instCreation));
     }
   }
 }