Initial version of completion plugin API

pkg/analysis_server/lib/completion/completion_core.dart

+// Copyright (c) 2015, 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 analysis_server.completion.completion_core;
+
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analysis_server/src/protocol.dart';
+import 'package:analyzer/src/generated/source.dart';
+
+abstract class CompletionContributor {
+  /**
+   * Compute a list of completion suggestions based on the given completion
+   * [request] and return a result that includes those suggestions. This method
+   * is called after specific phases of analysis until the contributor indicates
+   * computation is complete by setting [CompletionResult.isLast] to `true`.
+   */
+  CompletionResult computeSuggestions(CompletionRequest request);
+}
+
+/**
+ * The information about a requested list of completions.
+ */
+abstract class CompletionRequest {
+  /**
+   * Return the analysis context in which the completion is being requested.
+   */
+  AnalysisContext get context;
+
+  /**
+   * Return the results that were returned the last time the contributor was
+   * asked for results, or `null` if this is the first request for results at
+   * this location.
+   */
+  CompletionResult get previousResults;
+
+  /**
+   * Return the source in which the completion is being requested.
+   */
+  Source get source;
+
+  /**
+   * The offset within the source at which the completion is being requested.
+   */
+  int get offset;
+}
+
+abstract class CompletionResult {
+  /**
+   * Return `true` if this result contains suggestions that were not in the
+   * previously returned completion results. This should also be `true` if this
+   * is the first result produced for a given location.
+   */
+  bool get hasNewSuggestions;
+
+  /**
+   * Return `true` if the contributor has contributed all possible completion
+   * suggestions, or `false` if the contributor should be consulted again after
+   * more analysis has been completed.
+   */
+  bool get isLast;
+
+  /**
+   * Return the offset of the start of the text to be replaced. This will be
+   * different than the offset used to request the completion suggestions if
+   * there was a portion of text that needs to be replaced. For example, if a
+   * partial identifier is immediately before the original offset, in which case
+   * the replacementOffset will be the offset of the beginning of the
+   * identifier.
+   */
+  int get replacementOffset;
+
+  /**
+   * Return the length of the text to be replaced. This will be zero (0) if the
+   * suggestion is to be inserted, otherwise it will be greater than zero. For
+   * example, if the remainder of the identifier containing the cursor is to be
+   * replaced when the suggestion is applied, in which case the length will be
+   * the number of characters in the existing identifier.
+   */
+  int get replacementLength;
+
+  /**
+   * Return the list of suggestions being contributed by the contributor.
+   */
+  List<CompletionSuggestion> get suggestions;
+}