Initial work on refactorings.

pkg/analysis_services/lib/src/refactoring/rename.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.src.refactoring.rename;
+
+import 'package:analysis_services/correction/status.dart';
+import 'package:analysis_services/refactoring/progress_monitor.dart';
+import 'package:analysis_services/refactoring/refactoring.dart';
+import 'package:analysis_services/search/search_engine.dart';
+import 'package:analysis_services/src/correction/source_range.dart';
+import 'package:analysis_services/src/generated/change.dart';
+import 'package:analysis_services/src/refactoring/refactoring.dart';
+import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/source.dart';
+
+
+/**
+ * Returns the [Edit] to replace the given [SearchMatch] reference.
+ */
+Edit createReferenceEdit(SourceReference reference, String newText) {
+  return new Edit.range(reference.range, newText);
+}
+
+
+/**
+ * Returns `true` if two given [Element]s are [LocalElement]s and have
+ * intersecting with visibility ranges.
+ */
+bool haveIntersectingRanges(LocalElement localElement, Element element) {
+  if (element is! LocalElement) {
+    return false;
+  }
+  LocalElement localElement2 = element as LocalElement;
+  Source localSource = localElement.source;
+  Source localSource2 = localElement2.source;
+  SourceRange localRange = localElement.visibleRange;
+  SourceRange localRange2 = localElement2.visibleRange;
+  return localSource2 == localSource &&
+      localRange != null &&
+      localRange2 != null &&
+      localRange2.intersects(localRange);
+}
+
+
+/**
+ * Checks if the given [Element] is in the given [AnalysisContext].
+ */
+bool isInContext(Element element, AnalysisContext context) {
+  AnalysisContext elementContext = element.context;
+  if (elementContext == context) {
+    return true;
+  }
+  if (context is InstrumentedAnalysisContextImpl) {
+    return elementContext == context.basis;
+  }
+  return false;
+}
+
+
+/**
+ * Checks if the given [Element] is visible in the given [Source].
+ */
+bool isInTheSameLibrary(Element element, AnalysisContext context, Source source)

[Brian Wilkerson, 2014/08/11 16:27:47]

The comment and the name don't appear to correspond. And "in the same library"
as what?

[scheglov, 2014/08/11 18:06:25]

I've updated the comment.

+    {
+  // should be the same AnalysisContext
+  if (!isInContext(element, context)) {
+    return false;
+  }
+  // private elements are visible only in their library
+  List<Source> librarySourcesOfSource = context.getLibrariesContaining(source);
+  Source librarySourceOfElement = element.library.source;
+  return librarySourcesOfSource.contains(librarySourceOfElement);
+}
+
+
+/**
+ * Checks if the given [Element] is visible in the given [Source].
+ */
+bool isPublicOrInTheSameLibrary(Element element, AnalysisContext context,

[Brian Wilkerson, 2014/08/11 16:27:47]

This has the same comment as the previous function but clearly does something
different. The comments should make it clear what the difference is.

[scheglov, 2014/08/11 18:06:25]

I've updated the comment.

+    Source source) {
+  // should be the same AnalysisContext
+  if (!isInContext(element, context)) {
+    return false;
+  }
+  // public elements are always visible
+  if (element.isPublic) {
+    return true;
+  }
+  // private elements are visible only in their library
+  return isInTheSameLibrary(element, context, source);
+}
+
+
+/**
+ * Checks if the given unqualified [SearchMatch] intersects with visibility
+ * range of [localElement].
+ */
+bool isReferenceInLocalRange(LocalElement localElement, SearchMatch reference) {
+  if (reference.isQualified) {
+    return false;
+  }
+  Source localSource = localElement.source;
+  Source referenceSource = reference.element.source;
+  SourceRange localRange = localElement.visibleRange;
+  SourceRange referenceRange = reference.sourceRange;
+  return referenceSource == localSource &&
+      referenceRange.intersects(localRange);
+}
+
+
+/**
+ * An abstract implementation of [RenameRefactoring].
+ */
+abstract class RenameRefactoringImpl extends RefactoringImpl implements
+    RenameRefactoring {
+  final SearchEngine searchEngine;
+  final Element element;
+  AnalysisContext context;
+  String oldName;
+
+  String newName;
+
+  RenameRefactoringImpl(this.searchEngine, this.element) {
+    this.context = element.context;
+    this.oldName = _getDisplayName(element);
+  }
+
+  @override
+  String get currentName => element.displayName;

[Brian Wilkerson, 2014/08/11 16:27:47]

This seems strange. Should this be "oldName" so that imports are handled
correctly?

Is there a difference between "oldName" and "currentName"?

[scheglov, 2014/08/11 18:06:25]

The "currentName" field is gone now, "oldName" is used.

+
+  /**
+   * Adds the "Update declaration" [Edit] to [sourceChange].
+   */
+  void addDeclarationEdit(SourceChange sourceChange, Element element) {
+    Edit edit = new Edit.range(rangeElementName(element), newName);
+    addEdit(sourceChange, "Update declaration", edit);
+  }
+
+  /**
+   * Adds the [Edit] that replaces [oldName] in [sourceChange].
+   */
+  void addEdit(SourceChange sourceChange, String description, Edit edit) {

[Brian Wilkerson, 2014/08/11 16:27:47]

I don't understand the value of this method. Why is it better to write

  addEdit(sourceChange, description, edit)

rather than

  sourceChange.addEdit(edit, description)

[scheglov, 2014/08/11 18:06:25]

Done.

+    sourceChange.addEdit(edit, description);
+  }
+
+  /**
+   * Adds an "Update reference" [Edit] to [sourceChange].
+   */
+  void addReferenceEdit(SourceChange sourceChange, SourceReference reference) {
+    Edit edit = createReferenceEdit(reference, newName);

[Brian Wilkerson, 2014/08/11 16:27:47]

As far as I can see, this is the only use of "createReferenceEdit". Seems like
it would be better to in-line it.

[scheglov, 2014/08/11 18:06:25]

It will be used by other refactoring implementations.

+    addEdit(sourceChange, "Update reference", edit);
+  }
+
+  @override
+  RefactoringStatus checkInitialConditions(ProgressMonitor pm) {
+    return new RefactoringStatus();
+  }
+
+  @override
+  RefactoringStatus checkNewName(String newName) {
+    RefactoringStatus result = new RefactoringStatus();
+    if (newName == currentName) {
+      result.addFatalError("Choose another name.");

[Brian Wilkerson, 2014/08/11 16:27:47]

Is this user visible text? If so, perhaps something that explains why, such as
"The new name must be different than the current name."

[scheglov, 2014/08/11 18:06:25]

Done.

+    }
+    return result;
+  }
+
+  static String _getDisplayName(Element element) {
+    if (element is ImportElement) {
+      PrefixElement prefix = element.prefix;
+      if (prefix != null) {
+        return prefix.displayName;
+      }
+    }
+    return element.displayName;
+  }
+}
+
+
+/**
+ * The [SourceRange] in some [Source].
+ */
+class SourceReference {
+  final MatchKind kind;
+  final Source source;
+  final SourceRange range;
+
+  List<Element> elements = [];

[Brian Wilkerson, 2014/08/11 16:27:47]

This field isn't currently used (at least not in this class). Should it be
removed?

[scheglov, 2014/08/11 18:06:25]

Done.

+
+  SourceReference(this.kind, this.source, this.range);
+
+  @override
+  int get hashCode {
+    int hash = source.hashCode;
+    hash = ((hash << 16) & 0xFFFFFFFF) + range.hashCode;
+    return hash;
+  }
+
+  @override
+  bool operator ==(Object obj) {
+    if (identical(obj, this)) {
+      return true;
+    }
+    if (obj is! SourceReference) {
+      return false;
+    }
+    SourceReference other = obj as SourceReference;
+    return other.source == source && other.range == range;
+  }
+
+  @override
+  String toString() => '${source}@${range}';
+}