add inherited_computer.dart (TBR)

pkg/analysis_server/lib/src/services/completion/inherited_computer.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/completion/completion_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/services/completion/dart_completion_manager.dart'
+    show DART_RELEVANCE_HIGH;
+import 'package:analysis_server/utilities/change_builder_dart.dart';
+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.newElement_fromEngine(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;
+  }
+}