Issue 28261. Add support for implementing generic methods in Quick Fix.

pkg/analysis_server/lib/src/services/correction/util.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.src.correction.util;
 
 import 'dart:math';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart'
     show SourceChange, SourceEdit;
@@ skipping 681 matching lines @@
 
 class CorrectionUtils {
   final CompilationUnit unit;
 
   /**
    * The [ClassElement] the generated code is inserted to, so we can decide if
    * a type parameter may or may not be used.
    */
   ClassElement targetClassElement;
 
+  ExecutableElement targetExecutableElement;
+
   LibraryElement _library;
   String _buffer;
   String _endOfLine;
 
   CorrectionUtils(this.unit) {
     CompilationUnitElement unitElement = unit.element;
     AnalysisContext context = unitElement.context;
     if (context == null) {
       throw new CancelCorrectionException();
     }
@@ skipping 781 matching lines @@
       return _invertCondition0(expression.unParenthesized);
     }
     DartType type = expression.bestType;
     if (type.displayName == "bool") {
       return _InvertedCondition._simple("!${getNodeText(expression)}");
     }
     return _InvertedCondition._simple(getNodeText(expression));
   }
 
   /**
-   * Checks if [type] is visible at [targetOffset].
+   * Checks if [type] is visible in [targetExecutableElement] or
+   * [targetClassElement].
    */
   bool _isTypeVisible(DartType type) {
     if (type is TypeParameterType) {
       TypeParameterElement parameterElement = type.element;
       Element parameterClassElement = parameterElement.enclosingElement;
-      return identical(parameterClassElement, targetClassElement);
+      return identical(parameterClassElement, targetExecutableElement) ||
+          identical(parameterClassElement, targetClassElement);
     }
     return true;
   }
 
   /**
    * @return <code>true</code> if "selection" covers "range" and there are any non-whitespace tokens
    *         between "selection" and "range" start/end.
    */
   bool _selectionIncludesNonWhitespaceOutsideRange(
       SourceRange selection, SourceRange range) {
@@ skipping 141 matching lines @@
       _InvertedCondition expr, int newOperatorPrecedence) {
     if (expr._precedence < newOperatorPrecedence) {
       return "(${expr._source})";
     }
     return expr._source;
   }
 
   static _InvertedCondition _simple(String source) =>
       new _InvertedCondition(2147483647, source);
 }