Add hierarchy utils and use them in search.

pkg/analysis_services/lib/search/hierarchy.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.
+
+// This code was auto-generated, is not intended to be edited, and is subject to
+// significant change. Please see the README file for more information.
+
+library services.hierarchy;
+
+import 'dart:async';
+import 'dart:collection';
+
+import 'package:analysis_services/search/search_engine.dart';
+import 'package:analyzer/src/generated/element.dart';
+
+
+/**
+ * Returns direct children of [parent].
+ */
+List<Element> getChildren(Element parent, [String name]) {
+  List<Element> children = <Element>[];
+  parent.visitChildren(new _ElementVisitorAdapter((Element element) {
+    if (name == null || element.displayName == name) {
+      children.add(element);
+    }
+  }));
+  return children;
+}
+
+
+/**
+ * Returns direct non-synthetic children of the given [ClassElement].
+ *
+ * Includes: fields, accessors and methods.
+ * Excludes: constructors and synthetic elements.
+ */
+List<Element> getClassMembers(ClassElement clazz, [String name]) {
+  List<Element> members = <Element>[];
+  clazz.visitChildren(new _ElementVisitorAdapter((Element element) {
+    if (element.isSynthetic) {
+      return;
+    }
+    if (element is ConstructorElement) {
+      return;
+    }
+    if (name != null && element.displayName != name) {
+      return;
+    }
+    if (element is ExecutableElement) {
+      members.add(element);
+    }
+    if (element is FieldElement) {
+      members.add(element);
+    }
+  }));
+  return members;
+}
+
+
+/**
+ * Returns a [Set] with direct subclasses of [seed].
+ */
+Future<Set<ClassElement>> getDirectSubClasses(SearchEngine searchEngine,
+    ClassElement seed) {
+  return searchEngine.searchSubtypes(seed).then((List<SearchMatch> matches) {
+    Set<ClassElement> subClasses = new HashSet<ClassElement>();
+    for (SearchMatch match in matches) {
+      ClassElement subClass = match.element;
+      if (subClass.context == seed.context) {
+        subClasses.add(subClass);
+      }
+    }
+    return subClasses;
+  });
+}
+
+
+/**
+ * @return all implementations of the given {@link ClassMemberElement} is its superclasses and
+ *         their subclasses.
+ */
+Future<Set<ClassMemberElement>> getHierarchyMembers(SearchEngine searchEngine,
+    ClassMemberElement member) {
+  Set<ClassMemberElement> result = new HashSet<ClassMemberElement>();
+  // constructor
+  if (member is ConstructorElement) {
+    result.add(member);
+    return new Future.value(result);
+  }
+  // method, field, etc
+  String name = member.displayName;
+  ClassElement memberClass = member.enclosingElement;
+  List<Future> futures = <Future>[];
+  Set<ClassElement> searchClasses = getSuperClasses(memberClass);
+  searchClasses.add(memberClass);
+  for (ClassElement superClass in searchClasses) {
+    // ignore if super- class does not declare member
+    if (getClassMembers(superClass, name).isEmpty) {
+      continue;
+    }
+    // check all sub- classes
+    var subClassFuture = getSubClasses(searchEngine, superClass);
+    var membersFuture = subClassFuture.then((Set<ClassElement> subClasses) {
+      subClasses.add(superClass);
+      for (ClassElement subClass in subClasses) {
+        List<Element> subClassMembers = getChildren(subClass, name);
+        for (Element member in subClassMembers) {
+          if (member is ClassMemberElement) {
+            result.add(member);
+          }
+        }
+      }
+    });
+    futures.add(membersFuture);
+  }
+  return Future.wait(futures).then((_) {
+    return result;
+  });
+}
+
+
+/**
+ * Returns a [Set] with all direct and indirect subclasses of [seed].
+ */
+Future<Set<ClassElement>> getSubClasses(SearchEngine searchEngine,
+    ClassElement seed) {
+  Set<ClassElement> subs = new HashSet<ClassElement>();
+  // prepare queue
+  List<ClassElement> queue = new List<ClassElement>();
+  queue.add(seed);
+  // schedule subclasss search
+  addSubClasses() {
+    // add direct subclasses of the next class
+    while (queue.isNotEmpty) {
+      ClassElement clazz = queue.removeLast();
+      if (subs.add(clazz)) {
+        return getDirectSubClasses(searchEngine, clazz).then((directSubs) {
+          queue.addAll(directSubs);
+          return new Future(addSubClasses);
+        });
+      }
+    }
+    // done
+    subs.remove(seed);
+    return subs;
+  }
+  return new Future(addSubClasses);
+}
+
+
+/**
+ * Returns a [Set] with all direct and indirect superclasses of [seed].
+ */
+Set<ClassElement> getSuperClasses(ClassElement seed) {
+  Set<ClassElement> result = new HashSet<ClassElement>();
+  // prepare queue
+  List<ClassElement> queue = new List<ClassElement>();
+  queue.add(seed);
+  // process queue
+  while (!queue.isEmpty) {
+    ClassElement current = queue.removeLast();
+    // add if not checked already
+    if (!result.add(current)) {
+      continue;
+    }
+    // append supertype
+    {
+      InterfaceType superType = current.supertype;
+      if (superType != null) {
+        queue.add(superType.element);
+      }
+    }
+    // append interfaces
+    for (InterfaceType intf in current.interfaces) {
+      queue.add(intf.element);
+    }
+  }
+  // we don't need "seed" itself
+  result.remove(seed);
+  return result;
+}
+
+
+typedef void ElementProcessor(Element element);
+
+/**
+ * A [GeneralizingElementVisitor] adapter for [ElementProcessor].
+ */
+class _ElementVisitorAdapter extends GeneralizingElementVisitor {
+  final ElementProcessor processor;
+
+  _ElementVisitorAdapter(this.processor);
+
+  @override
+  void visitElement(Element element) {
+    processor(element);
+  }
+}