Formatter service API tweaks.

pkg/analysis_server/lib/src/edit/edit_domain.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 edit.domain;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/collections.dart';
@@ skipping 55 matching lines @@
       return new Response.formatInvalidFile(request);
     }
 
     Source source = server.getSource(file);
     engine.TimestampedData<String> contents;
     try {
       contents = context.getContents(source);
     } catch (e) {
       return new Response.formatInvalidFile(request);
     }
+
     String unformattedSource = contents.data;
 
+    int start = params.selectionOffset;
+    int length = params.selectionLength;
+
+    // No need to preserve 0,0 selection
+    if (start == 0 && length == 0) {
+      start = null;
+      length = null;
+    }
+
     SourceCode code = new SourceCode(
         unformattedSource,
         uri: null,
         isCompilationUnit: true,
-        selectionStart: params.selectionOffset,
-        selectionLength: params.selectionLength);
+        selectionStart: start,
+        selectionLength: length);
     DartFormatter formatter = new DartFormatter();
     SourceCode formattedResult = formatter.formatSource(code);
     String formattedSource = formattedResult.text;
 
     List<SourceEdit> edits = <SourceEdit>[];
 
     if (formattedSource != unformattedSource) {
       //TODO: replace full replacements with smaller, more targeted edits
       SourceEdit edit =
           new SourceEdit(0, unformattedSource.length, formattedSource);
@@ skipping 511 matching lines @@
     }
     if (refactoring is RenameRefactoring) {
       RenameRefactoring renameRefactoring = refactoring;
       RenameOptions renameOptions = params.options;
       renameRefactoring.newName = renameOptions.newName;
       return renameRefactoring.checkNewName();
     }
     return new RefactoringStatus();
   }
 }