Initial version of completion plugin API

pkg/analysis_server/lib/src/plugin/server_plugin.dart

Index: pkg/analysis_server/lib/src/plugin/server_plugin.dart
diff --git a/pkg/analysis_server/lib/src/plugin/server_plugin.dart b/pkg/analysis_server/lib/src/plugin/server_plugin.dart
index 3d02551cada7fb264b9196ed5c5a526b164a2667..ddec2dca6ebb532ba2cde6843f96be54dca2b5ca 100644
--- a/pkg/analysis_server/lib/src/plugin/server_plugin.dart
+++ b/pkg/analysis_server/lib/src/plugin/server_plugin.dart
@@ -4,9 +4,11 @@
 
 library analysis_server.src.plugin.server_plugin;
 
+import 'package:analysis_server/completion/completion_core.dart';
 import 'package:analysis_server/edit/assist/assist_core.dart';
 import 'package:analysis_server/edit/fix/fix_core.dart';
 import 'package:analysis_server/plugin/assist.dart';
+//import 'package:analysis_server/plugin/completion.dart';
 import 'package:analysis_server/plugin/fix.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
@@ -39,6 +41,13 @@ class ServerPlugin implements Plugin {
 
   /**
    * The simple identifier of the extension point that allows plugins to
+   * register new completion contributors with the server.
+   */
+  static const String COMPLETION_CONTRIBUTOR_EXTENSION_POINT =
+      'completionContributor';
+
+  /**
+   * The simple identifier of the extension point that allows plugins to
    * register new domains with the server.
    */
   static const String DOMAIN_EXTENSION_POINT = 'domain';
@@ -61,6 +70,12 @@ class ServerPlugin implements Plugin {
   ExtensionPoint assistContributorExtensionPoint;
 
   /**
+   * The extension point that allows plugins to register new completion
+   * contributors with the server.
+   */
+  ExtensionPoint completionContributorExtensionPoint;
+
+  /**
    * The extension point that allows plugins to register new domains with the
    * server.
    */
@@ -77,15 +92,28 @@ class ServerPlugin implements Plugin {
    */
   ServerPlugin();
 
-  @override
-  String get uniqueIdentifier => UNIQUE_IDENTIFIER;
+  /**
+   * Return a list containing all of the assist contributors that were
+   * contributed.
+   */
+  List<AssistContributor> get assistContributors =>
+      assistContributorExtensionPoint.extensions;
+
+  /**
+   * Return a list containing all of the completion contributors that were
+   * contributed.
+   */
+  List<CompletionContributor> get completionContributors =>
+      completionContributorExtensionPoint.extensions;
 
   /**
    * Return a list containing all of the fix contributors that were contributed.
    */
-  List<AssistContributor> assistContributors() {
-    return assistContributorExtensionPoint.extensions;
-  }
+  List<FixContributor> get fixContributors =>
+      fixContributorExtensionPoint.extensions;
+
+  @override
+  String get uniqueIdentifier => UNIQUE_IDENTIFIER;
 
   /**
    * Use the given [server] to create all of the domains ([RequestHandler]'s)
@@ -100,18 +128,14 @@ class ServerPlugin implements Plugin {
         .toList();
   }
 
-  /**
-   * Return a list containing all of the fix contributors that were contributed.
-   */
-  List<FixContributor> fixContributors() {
-    return fixContributorExtensionPoint.extensions;
-  }
-
   @override
   void registerExtensionPoints(RegisterExtensionPoint registerExtensionPoint) {
     assistContributorExtensionPoint = registerExtensionPoint(
         ASSIST_CONTRIBUTOR_EXTENSION_POINT,
         _validateAssistContributorExtension);
+    completionContributorExtensionPoint = registerExtensionPoint(
+        COMPLETION_CONTRIBUTOR_EXTENSION_POINT,
+        _validateCompletionContributorExtension);
     domainExtensionPoint = registerExtensionPoint(
         DOMAIN_EXTENSION_POINT, _validateDomainExtension);
     fixContributorExtensionPoint = registerExtensionPoint(
@@ -126,6 +150,12 @@ class ServerPlugin implements Plugin {
     registerExtension(
         ASSIST_CONTRIBUTOR_EXTENSION_POINT_ID, new DefaultAssistContributor());
     //
+    // Register completion contributors.
+    //
+    // TODO(brianwilkerson) Register the completion contributors.
+//    registerExtension(
+//        COMPLETION_CONTRIBUTOR_EXTENSION_POINT_ID, ???);
+    //
     // Register domains.
     //
     String domainId = Plugin.join(UNIQUE_IDENTIFIER, DOMAIN_EXTENSION_POINT);
@@ -150,7 +180,7 @@ class ServerPlugin implements Plugin {
 
   /**
    * Validate the given extension by throwing an [ExtensionError] if it is not a
-   * valid fix contributor.
+   * valid assist contributor.
    */
   void _validateAssistContributorExtension(Object extension) {
     if (extension is! AssistContributor) {
@@ -162,6 +192,18 @@ class ServerPlugin implements Plugin {
 
   /**
    * Validate the given extension by throwing an [ExtensionError] if it is not a
+   * valid completion contributor.
+   */
+  void _validateCompletionContributorExtension(Object extension) {
+    if (extension is! CompletionContributor) {
+      String id = completionContributorExtensionPoint.uniqueIdentifier;
+      throw new ExtensionError(
+          'Extensions to $id must be an CompletionContributor');
+    }
+  }
+
+  /**
+   * Validate the given extension by throwing an [ExtensionError] if it is not a
    * valid domain.
    */
   void _validateDomainExtension(Object extension) {