improve element parameter string returned by local suggestion computer

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

 // Copyright (c) 2014, 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.computer.dart.local;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart' as protocol show Element,
     ElementKind;
@@ skipping 278 matching lines @@
     });
   }
 
   void _addClassSuggestion(ClassDeclaration declaration) {
     CompletionSuggestion suggestion =
         _addSuggestion(declaration.name, CompletionSuggestionKind.CLASS, null, null);
     if (suggestion != null) {
       suggestion.element = _createElement(
           protocol.ElementKind.CLASS,
           declaration.name,
+          null,
           NO_RETURN_TYPE,
           declaration.isAbstract,
           _isDeprecated(declaration.metadata));
     }
   }
 
   void _addFieldSuggestions(ClassDeclaration node, FieldDeclaration fieldDecl) {
     if (typesOnly) {
       return;
     }
     bool isDeprecated = _isDeprecated(fieldDecl.metadata);
     fieldDecl.fields.variables.forEach((VariableDeclaration varDecl) {
       CompletionSuggestion suggestion = _addSuggestion(
           varDecl.name,
           CompletionSuggestionKind.GETTER,
           fieldDecl.fields.type,
           node);
       if (suggestion != null) {
         suggestion.element = _createElement(
             protocol.ElementKind.GETTER,
             varDecl.name,
+            '()',
             fieldDecl.fields.type,
             false,
             isDeprecated || _isDeprecated(varDecl.metadata));
       }
     });
   }
 
   void _addFunctionSuggestion(FunctionDeclaration declaration) {
     if (typesOnly) {
       return;
     }
     if (excludeVoidReturn && _isVoid(declaration.returnType)) {
       return;
     }
     CompletionSuggestion suggestion = _addSuggestion(
         declaration.name,
         CompletionSuggestionKind.FUNCTION,
         declaration.returnType,
         null);
     if (suggestion != null) {
       suggestion.element = _createElement(
           protocol.ElementKind.FUNCTION,
           declaration.name,
+          declaration.functionExpression.parameters.toSource(),
           declaration.returnType,
           false,
           _isDeprecated(declaration.metadata));
     }
   }
 
   void _addLocalVarSuggestion(SimpleIdentifier id, TypeName returnType) {
     if (typesOnly) {
       return;
     }
     CompletionSuggestion suggestion =
         _addSuggestion(id, CompletionSuggestionKind.LOCAL_VARIABLE, returnType, null);
     if (suggestion != null) {
       suggestion.element = _createElement(
           protocol.ElementKind.LOCAL_VARIABLE,
           id,
+          null,
           returnType,
           false,
           false);
     }
   }
 
   void _addMethodSuggestion(ClassDeclaration node, MethodDeclaration classMbr) {
     if (typesOnly) {
       return;
     }
     protocol.ElementKind kind;
     CompletionSuggestionKind csKind;
+    String parameters;
     if (classMbr.isGetter) {
       kind = protocol.ElementKind.GETTER;
       csKind = CompletionSuggestionKind.GETTER;
+      parameters = '()';
     } else if (classMbr.isSetter) {
       if (excludeVoidReturn) {
         return;
       }
       kind = protocol.ElementKind.SETTER;
       csKind = CompletionSuggestionKind.SETTER;
+      parameters = '(${classMbr.returnType.toSource()} value)';
     } else {
       if (excludeVoidReturn && _isVoid(classMbr.returnType)) {
         return;
       }
       kind = protocol.ElementKind.METHOD;
       csKind = CompletionSuggestionKind.METHOD;
+      parameters = classMbr.parameters.toSource();
     }
     CompletionSuggestion suggestion =
         _addSuggestion(classMbr.name, csKind, classMbr.returnType, node);
     if (suggestion != null) {
       suggestion.element = _createElement(
           kind,
           classMbr.name,
+          parameters,
           classMbr.returnType,
           classMbr.isAbstract,
           _isDeprecated(classMbr.metadata));
     }
   }
 
   void _addParamListSuggestions(FormalParameterList paramList) {
     if (typesOnly) {
       return;
     }
@@ skipping 18 matching lines @@
     }
   }
 
   void _addParamSuggestion(SimpleIdentifier identifier, TypeName type) {
     if (typesOnly) {
       return;
     }
     CompletionSuggestion suggestion =
         _addSuggestion(identifier, CompletionSuggestionKind.PARAMETER, type, null);
     if (suggestion != null) {
-      suggestion.element =
-          _createElement(protocol.ElementKind.PARAMETER, identifier, type, false, false);
+      suggestion.element = _createElement(
+          protocol.ElementKind.PARAMETER,
+          identifier,
+          null,
+          type,
+          false,
+          false);
     }
   }
 
   CompletionSuggestion _addSuggestion(SimpleIdentifier id,
       CompletionSuggestionKind kind, TypeName typeName, ClassDeclaration classDecl) {
     if (id != null) {
       String completion = id.name;
       if (completion != null && completion.length > 0 && completion != '_') {
         CompletionSuggestion suggestion = new CompletionSuggestion(
             kind,
@@ skipping 37 matching lines @@
       varList.variables.forEach((VariableDeclaration varDecl) {
         CompletionSuggestion suggestion = _addSuggestion(
             varDecl.name,
             CompletionSuggestionKind.TOP_LEVEL_VARIABLE,
             varList.type,
             null);
         if (suggestion != null) {
           suggestion.element = _createElement(
               protocol.ElementKind.TOP_LEVEL_VARIABLE,
               varDecl.name,
+              null,
               varList.type,
               false,
               isDeprecated || _isDeprecated(varDecl.metadata));
         }
       });
     }
   }
 
   bool _computeExcludeVoidReturn(AstNode node) {
     if (node is Block) {
       return false;
     } else if (node is SimpleIdentifier) {
       return node.parent is ExpressionStatement ? false : true;
     } else {
       return true;
     }
   }
 
   /**
    * Create a new protocol Element for inclusion in a completion suggestion.
    */
   protocol.Element _createElement(protocol.ElementKind kind,
-      SimpleIdentifier id, TypeName returnType, bool isAbstract, bool isDeprecated) {
+      SimpleIdentifier id, String parameters, TypeName returnType,
+      bool isAbstract, bool isDeprecated) {
     String name = id.name;
     int flags = protocol.Element.makeFlags(
         isAbstract: isAbstract,
         isDeprecated: isDeprecated,
         isPrivate: Identifier.isPrivateName(name));
     return new protocol.Element(
         kind,
         name,
         flags,
+        parameters: parameters,
         returnType: _nameForType(returnType));
   }
 
   /**
    * Return `true` if the @deprecated annotation is present
    */
   bool _isDeprecated(NodeList<Annotation> metadata) =>
       metadata != null &&
           metadata.any(
               (Annotation a) => a.name is SimpleIdentifier && a.name.name == 'deprecated');
@@ skipping 26 matching lines @@
     if (name == null || name.length <= 0) {
       return DYNAMIC;
     }
     TypeArgumentList typeArgs = type.typeArguments;
     if (typeArgs != null) {
       //TODO (danrubel) include type arguments
     }
     return name;
   }
 }