'Rename Import Prefix' refactoring.

pkg/analysis_services/lib/src/refactoring/rename_import.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.src.refactoring.rename_import;
+
+import 'dart:async';
+
+import 'package:analysis_services/correction/change.dart';
+import 'package:analysis_services/correction/status.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/refactoring/naming_conventions.dart';
+import 'package:analysis_services/src/refactoring/rename.dart';
+import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/source.dart';
+
+
+/**
+ * A [Refactoring] for renaming [ImportElement]s.
+ */
+class RenameImportRefactoringImpl extends RenameRefactoringImpl {
+  RenameImportRefactoringImpl(SearchEngine searchEngine, ImportElement element)
+      : super(searchEngine, element);
+
+  @override
+  ImportElement get element => super.element as ImportElement;
+
+  @override
+  String get refactoringName {
+    return "Rename Import Prefix";
+  }
+
+  @override
+  Future<RefactoringStatus> checkFinalConditions() {
+    RefactoringStatus result = new RefactoringStatus();
+    return new Future.value(result);
+  }
+
+  @override
+  RefactoringStatus checkNewName() {
+    RefactoringStatus result = super.checkNewName();
+    result.addStatus(validateImportPrefixName(newName));
+    return result;
+  }
+
+  @override
+  Future<Change> createChange() {
+    Change change = new Change(refactoringName);
+    // update declaration
+    {
+      String file = getElementFile(element);
+      PrefixElement prefix = element.prefix;
+      Edit edit = null;
+      if (newName.isEmpty) {
+        int uriEnd = element.uriEnd;
+        int prefixEnd = element.prefixOffset + prefix.displayName.length;
+        SourceRange range = rangeStartEnd(uriEnd, prefixEnd);
+        edit = new Edit.range(range, "");
+      } else {
+        if (prefix == null) {
+          SourceRange range = rangeStartLength(element.uriEnd, 0);
+          edit = new Edit.range(range, " as ${newName}");
+        } else {
+          int offset = element.prefixOffset;
+          int length = prefix.displayName.length;
+          SourceRange range = rangeStartLength(offset, length);
+          edit = new Edit.range(range, newName);
+        }
+      }
+      if (edit != null) {
+        change.addEdit(file, edit);
+      }
+    }
+    // update references
+    return searchEngine.searchReferences(element).then((refMatches) {
+      List<SourceReference> references = getSourceReferences(refMatches);
+      for (SourceReference reference in references) {
+        Edit edit;
+        if (newName.isEmpty) {
+          edit = createReferenceEdit(reference, newName);
+        } else {
+          edit = createReferenceEdit(reference, "${newName}.");
+        }
+        change.addEdit(reference.file, edit);
+      }
+      return change;
+    });
+  }
+}