step toward new completion API

pkg/analysis_server/lib/src/services/completion/inherited_contributor.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 services.completion.computer.dart.invocation;
-
-import 'package:analysis_server/plugin/edit/utilities/change_builder_dart.dart';
-import 'package:analysis_server/src/protocol_server.dart'
-    show CompletionSuggestion, CompletionSuggestionKind, SourceChange;
-import 'package:analysis_server/src/protocol_server.dart' as protocol
-    hide CompletionSuggestion, CompletionSuggestionKind;
-import 'package:analysis_server/src/provisional/completion/completion_dart.dart';
-import 'package:analysis_server/src/services/completion/dart_completion_manager.dart'
-    show DART_RELEVANCE_HIGH;
-import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/element.dart';
-import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/resolver.dart';
-import 'package:analyzer/src/generated/source.dart';
-
-/**
- * A completion contributor used to suggest replacing partial identifiers inside
- * a class declaration with templates for inherited members.
- */
-class InheritedContributor extends DartCompletionContributor {
-  @override
-  List<CompletionSuggestion> internalComputeSuggestions(
-      DartCompletionRequest request) {
-    if (!request.isResolved) {
-      return null;
-    }
-    AstNode node = new NodeLocator(request.offset).searchWithin(request.unit);
-    if (node == null || !_isMemberLevelIdentifier(node)) {
-      return null;
-    }
-    ClassDeclaration classDeclaration =
-        node.getAncestor((AstNode node) => node is ClassDeclaration);
-    if (classDeclaration != null) {
-      ClassElement element = classDeclaration.element;
-      if (element == null) {
-        return null;
-      }
-      return _suggestInheritedMembers(request, node, element);
-    }
-    return null;
-  }
-
-  /**
-   * Return a template for an override of the given [element] in the given
-   * [source]. If selected, the template will replace the given [identifier].
-   */
-  String _buildRepacementText(
-      Source source, SimpleIdentifier identifier, Element element) {
-    AnalysisContext context = element.context;
-    DartChangeBuilder builder = new DartChangeBuilder(context);
-    builder.addFileEdit(source, context.getModificationStamp(source),
-        (DartFileEditBuilder builder) {
-      builder.addReplacement(identifier.offset, identifier.length,
-          (DartEditBuilder builder) {
-        builder.writeOverrideOfInheritedMember(element);
-      });
-    });
-    return builder.sourceChange.edits[0].edits[0].replacement.trim();
-  }
-
-  /**
-   * Build a suggestion to replace the partial [identifier] in the given
-   * [source] with an override of the given [element].
-   */
-  CompletionSuggestion _buildSuggestion(
-      Source source, SimpleIdentifier identifier, Element element) {
-    String completion = _buildRepacementText(source, identifier, element);
-    CompletionSuggestion suggestion = new CompletionSuggestion(
-        CompletionSuggestionKind.IDENTIFIER,
-        DART_RELEVANCE_HIGH,
-        completion,
-        identifier.offset,
-        0,
-        element.isDeprecated,
-        false);
-    suggestion.element = protocol.convertElement(element);
-    return suggestion;
-  }
-
-  /**
-   * Return a list containing the names of all of the inherited by not
-   * implemented members of the class represented by the given [element] that
-   * start with the given [prefix]. The [map] is used to find all of the members
-   * that are inherited.
-   */
-  List<String> _computeMemberNames(
-      MemberMap map, ClassElement element, String prefix) {
-    List<String> memberNames = <String>[];
-    int count = map.size;
-    for (int i = 0; i < count; i++) {
-      String memberName = map.getKey(i);
-      if (memberName.startsWith(prefix) && !_hasMember(element, memberName)) {
-        memberNames.add(memberName);
-      }
-    }
-    return memberNames;
-  }
-
-  /**
-   * Return `true` if the given [classElement] directly declares a member with
-   * the given [memberName].
-   */
-  bool _hasMember(ClassElement classElement, String memberName) {
-    return classElement.getField(memberName) != null ||
-        classElement.getGetter(memberName) != null ||
-        classElement.getMethod(memberName) != null ||
-        classElement.getSetter(memberName) != null;
-  }
-
-  /**
-   * Return `true` if the given [node] looks like a partial identifier inside a
-   * class declaration.
-   */
-  bool _isMemberLevelIdentifier(AstNode node) {
-    if (node is SimpleIdentifier) {
-      AstNode parent1 = node.parent;
-      if (parent1 is TypeName) {
-        AstNode parent2 = parent1.parent;
-        if (parent2 is VariableDeclarationList) {
-          AstNode parent3 = parent2.parent;
-          if (parent3 is FieldDeclaration) {
-            NodeList<VariableDeclaration> variables = parent2.variables;
-            return variables.length == 1 && variables[0].name.name.isEmpty;
-          }
-        }
-      }
-    }
-    return false;
-  }
-
-  /**
-   * Add any suggestions that are appropriate to the given [request], using the
-   * given [element] to find inherited members whose name has the given
-   * [identifier] as a prefix.
-   */
-  List<CompletionSuggestion> _suggestInheritedMembers(
-      DartCompletionRequest request,
-      SimpleIdentifier identifier,
-      ClassElement element) {
-    String name = identifier.name;
-    InheritanceManager manager = new InheritanceManager(element.library);
-    MemberMap map = manager.getMapOfMembersInheritedFromInterfaces(element);
-    List<String> memberNames = _computeMemberNames(map, element, name);
-    memberNames.sort();
-    List<CompletionSuggestion> suggestions = <CompletionSuggestion>[];
-    for (String memberName in memberNames) {
-      CompletionSuggestion suggestion =
-          _buildSuggestion(request.source, identifier, map.get(memberName));
-      if (suggestion != null) {
-        suggestions.add(suggestion);
-      }
-    }
-    return suggestions;
-  }
-}