use CompletionTarget for replacement offset/length

pkg/analysis_server/lib/src/services/completion/dart_completion_manager.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.dart;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/arglist_computer.dart';
 import 'package:analysis_server/src/services/completion/combinator_computer.dart';
 import 'package:analysis_server/src/services/completion/completion_manager.dart';
 import 'package:analysis_server/src/services/completion/completion_target.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_cache.dart';
 import 'package:analysis_server/src/services/completion/imported_computer.dart';
 import 'package:analysis_server/src/services/completion/invocation_computer.dart';
 import 'package:analysis_server/src/services/completion/keyword_computer.dart';
 import 'package:analysis_server/src/services/completion/local_computer.dart';
 import 'package:analysis_server/src/services/completion/optype.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/generated/scanner.dart';
 
 // TODO (danrubel) these are temporary constants as we transition completion
 // relevance from CompletionRelevance.LOW/DEFAULT/HIGH to int.
 // These should be removed in a subsequent CL
 const int COMPLETION_RELEVANCE_LOW = 500;
 const int COMPLETION_RELEVANCE_DEFAULT = 1000;
 const int COMPLETION_RELEVANCE_HIGH = 2000;
 
 /**
  * The base class for computing code completion suggestions.
@@ skipping 20 matching lines @@
 
 /**
  * Manages code completion for a given Dart file completion request.
  */
 class DartCompletionManager extends CompletionManager {
   final SearchEngine searchEngine;
   final DartCompletionCache cache;
   List<DartCompletionComputer> computers;
 
   DartCompletionManager(AnalysisContext context, this.searchEngine,
-      Source source, this.cache)
-      : super(context, source),
-        computers = [
+      Source source, this.cache, [this.computers])
+      : super(context, source) {
+    if (computers == null) {
+      computers = [
           new KeywordComputer(),
           new LocalComputer(),
           new ArgListComputer(),
           new CombinatorComputer(),
           new ImportedComputer(),
           new InvocationComputer()];
+    }
+  }
 
   /**
    * Create a new initialized Dart source completion manager
    */
   factory DartCompletionManager.create(AnalysisContext context,
       SearchEngine searchEngine, Source source) {
     return new DartCompletionManager(
         context,
         searchEngine,
         source,
@@ skipping 14 matching lines @@
   /**
    * Compute suggestions based upon cached information only
    * then send an initial response to the client.
    * Return a list of computers for which [computeFull] should be called
    */
   List<DartCompletionComputer> computeFast(DartCompletionRequest request) {
     return request.performance.logElapseTime('computeFast', () {
       CompilationUnit unit = context.parseCompilationUnit(source);
       request.unit = unit;
       request.node = new NodeLocator.con1(request.offset).searchWithin(unit);
-      request.node.accept(new _ReplacementOffsetBuilder(request));
       request.target = new CompletionTarget.forOffset(unit, request.offset);
+
+      request.replacementOffset = request.offset;
+      request.replacementLength = 0;
+      var entity = request.target.entity;
+      Token token = entity is AstNode ? entity.beginToken : entity;
+      if (token != null &&
+          token.offset <= request.offset &&
+          (token.type == TokenType.KEYWORD || token.type == TokenType.IDENTIFIER)) {
+        request.replacementOffset = token.offset;
+        request.replacementLength = token.length;
+      }
+
       List<DartCompletionComputer> todo = new List.from(computers);
       todo.removeWhere((DartCompletionComputer c) {
         return request.performance.logElapseTime(
             'computeFast ${c.runtimeType}',
             () {
           return c.computeFast(request);
         });
       });
       sendResults(request, todo.isEmpty);
       return todo;
     });
   }
 
   /**
    * If there is remaining work to be done, then wait for the unit to be
    * resolved and request that each remaining computer finish their work.
+   * Return a [Future] that completes when the last notification has been sent.
    */
-  void computeFull(DartCompletionRequest request,
+  Future computeFull(DartCompletionRequest request,
       List<DartCompletionComputer> todo) {
     request.performance.logStartTime('waitForAnalysis');
-    waitForAnalysis().then((CompilationUnit unit) {
+    return waitForAnalysis().then((CompilationUnit unit) {
       if (controller.isClosed) {
         return;
       }
       request.performance.logElapseTime('waitForAnalysis');
       if (unit == null) {
         sendResults(request, true);
         return;
       }
       request.performance.logElapseTime('computeFull', () {
         request.unit = unit;
@@ skipping 34 matching lines @@
       if (!todo.isEmpty) {
         computeFull(request, todo);
       }
     });
   }
 
   /**
    * Send the current list of suggestions to the client.
    */
   void sendResults(DartCompletionRequest request, bool last) {
-    if (controller.isClosed) {
+    if (controller == null || controller.isClosed) {
       return;
     }
     controller.add(
         new CompletionResult(
             request.replacementOffset,
             request.replacementLength,
             request.suggestions,
             last));
     if (last) {
       controller.close();
@@ skipping 113 matching lines @@
    * Information about the types of suggestions that should be included.
    * The [target] must be set first.
    */
   OpType get optype {
     if (_optype == null) {
       _optype = new OpType.forCompletion(target, offset);
     }
     return _optype;
   }
 }
-
-/**
- * Visitor used to determine the replacement offset and length
- * based upon the cursor location.
- */
-class _ReplacementOffsetBuilder extends SimpleAstVisitor {
-  final DartCompletionRequest request;
-
-  _ReplacementOffsetBuilder(this.request) {
-    request.replacementOffset = request.offset;
-    request.replacementLength = 0;
-  }
-
-  visitSimpleIdentifier(SimpleIdentifier node) {
-    request.replacementOffset = node.offset;
-    request.replacementLength = node.length;
-  }
-}