first incomplete cut at invocation/accessor suggestions

pkg/analysis_services/lib/src/completion/invocation_computer.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.computer.dart.invocation;
+
+import 'dart:async';
+
+import 'package:analysis_services/completion/completion_computer.dart';
+import 'package:analysis_services/completion/completion_suggestion.dart';
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/element.dart';
+
+/**
+ * A computer for calculating invocation / access suggestions
+ * `completion.getSuggestions` request results.
+ */
+class InvocationComputer extends CompletionComputer {
+
+  @override
+  bool computeFast(CompilationUnit unit, AstNode node,
+      List<CompletionSuggestion> suggestions) {
+    // TODO: implement computeFast
+    return false;
+  }
+
+  @override
+  Future<bool> computeFull(CompilationUnit unit, AstNode node,
+      List<CompletionSuggestion> suggestions) {
+    return node.accept(new _InvocationAstVisitor(unit, offset, suggestions));
+  }
+}
+
+/**
+ * An [AstNode] vistor for determining the appropriate invocation/access
+ * suggestions based upon the node in which the completion is requested.
+ */
+class _InvocationAstVisitor extends GeneralizingAstVisitor<Future<bool>> {
+  final CompilationUnit unit;
+  final int offset;
+  final List<CompletionSuggestion> suggestions;
+  AstNode completionNode;
+
+  _InvocationAstVisitor(this.unit, this.offset, this.suggestions);
+
+  Future<bool> visitNode(AstNode node) {
+    return new Future.value(false);
+  }
+
+  Future<bool> visitPrefixedIdentifier(PrefixedIdentifier node) {
+    if (node.identifier == completionNode) {
+      return _addSuggestions(node.prefix.bestElement);
+    }
+    return super.visitPrefixedIdentifier(node);
+  }
+
+  Future<bool> visitSimpleIdentifier(SimpleIdentifier node) {
+    completionNode = node;
+    return node.parent.accept(this);
+  }
+
+  /**
+   * Add invocation / access suggestions for the given element.
+   */
+  Future<bool> _addSuggestions(Element element) {
+    if (element != null) {
+      return element.accept(new _InvocationElementVisitor(suggestions));
+    }
+    return new Future.value(false);
+  }
+}
+
+/**
+ * An [Element] visitor for determining the appropriate invocation/access
+ * suggestions based upon the element for which the completion is requested.
+ */
+class _InvocationElementVisitor extends GeneralizingElementVisitor<Future<bool>>
+    {
+  final List<CompletionSuggestion> suggestions;
+
+  _InvocationElementVisitor(this.suggestions);
+
+  Future<bool> visitElement(Element element) {
+    return new Future.value(false);
+  }
+
+  Future<bool> visitVariableElement(VariableElement element) {
+    return _addSuggestions(element.type);
+  }
+
+  Future<bool> _addSuggestions(DartType type) {
+    if (type != null && type.element != null) {
+      type.element.accept(new _SuggestionBuilderVisitor(suggestions));
+      return new Future.value(true);
+    }
+    return new Future.value(false);
+  }
+}
+
+/**
+ * An [Element] visitor that builds suggestions by recursively visiting
+ * elements in a type hierarchy.
+ */
+class _SuggestionBuilderVisitor extends GeneralizingElementVisitor {
+  final List<CompletionSuggestion> suggestions;
+
+  _SuggestionBuilderVisitor(this.suggestions);
+
+  visitClassElement(ClassElement element) {
+    //TODO (danrubel): filter private members if not in the same library
+    element.visitChildren(this);
+  }
+
+  visitElement(Element element) {
+    // ignored
+  }
+
+  visitFieldElement(FieldElement element) {
+    if (!element.isSynthetic) {
+      _addSuggestion(element, CompletionSuggestionKind.FIELD);
+    }
+  }
+
+  visitMethodElement(MethodElement element) {
+    if (!element.isSynthetic) {
+      _addSuggestion(element, CompletionSuggestionKind.METHOD);
+    }
+  }
+
+  visitPropertyAccessorElement(PropertyAccessorElement element) {
+    if (!element.isSynthetic) {
+      if (element.isGetter) {
+        _addSuggestion(element, CompletionSuggestionKind.GETTER);
+      } else if (element.isSetter) {
+        _addSuggestion(
+            element,
+            CompletionSuggestionKind.SETTER,
+            element.displayName);
+      }
+    }
+  }
+
+  void _addSuggestion(Element element, CompletionSuggestionKind kind,
+      [String completion = null]) {
+    if (completion == null) {
+      completion = element.name;
+    }
+    if (completion != null && completion.length > 0) {
+      suggestions.add(
+          new CompletionSuggestion(
+              kind,
+              CompletionRelevance.DEFAULT,
+              completion,
+              completion.length,
+              0,
+              element.isDeprecated,
+              false /* isPotential */));
+    }
+  }
+}