Add Directory.createTemp() to asynchronously create a temporary directory.

runtime/bin/directory_impl.dart

 // Copyright (c) 2011, 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.
 
 
 class _DirectoryListingIsolate extends Isolate {
 
   _DirectoryListingIsolate() : super.heavy();
 
   void main() {
@@ skipping 11 matching lines @@
 
   bool _list(String dir,
              bool recursive,
              SendPort dirPort,
              SendPort filePort,
              SendPort donePort,
              SendPort errorPort) native "Directory_List";
 }
 
 
+class _DirectoryCreateTempIsolate extends Isolate {
+
+  _DirectoryCreateTempIsolate() : super.heavy();
+
+  void main() {
+    port.receive((path, replyTo) {
+      // Call function to get file name
+      replyTo.send(_createTemp(path, (Math.random() * 0x8000000).toInt()));
+      port.close();
+    });
+  }
+
+  String _createTemp(String template, int num) native "Directory_CreateTemp";
+}
+
+
 class _Directory implements Directory {
 
   _Directory(String this._path);
 
   bool existsSync() {
     int exists = _exists(_path);
     if (exists < 0) {
       throw new DirectoryException("Diretory exists test failed: $_path");
     }
     return (exists == 1);
   }
 
   void createSync() {
     if (!_create(_path)) {
       throw new DirectoryException("Directory creation failed: $_path");
     }
   }
 
+  void createTemp() {
+    new _DirectoryCreateTempIsolate().spawn().then((port) {
+      port.call(_path).receive((result, ignored) {
+        if (result != '') {
+          _path = result;
+          if (_createTempHandler !== null) {
+            _createTempHandler();
+          }
+        } else {
+          if (_errorHandler !== null) {
+            _errorHandler("Could not create temporary directory: $_path");
+          }
+        }
+      });
+    });
+  }
+
   void deleteSync() {
     if (!_delete(_path)) {
       throw new DirectoryException("Directory deletion failed: $_path");
     }
   }
 
   void list([bool recursive = false]) {
     new _DirectoryListingIsolate().spawn().then((port) {
       // Build a map of parameters to the directory listing isolate.
       Map listingParameters = new Map();
@@ skipping 62 matching lines @@
   }
 
   void set fileHandler(void fileHandler(String file)) {
     _fileHandler = fileHandler;
   }
 
   void set doneHandler(void doneHandler(bool completed)) {
     _doneHandler = doneHandler;
   }
 
+  void set createTempHandler(void createTempHandler()) {
+    _createTempHandler = createTempHandler;
+  }
+
   void set errorHandler(void errorHandler(String error)) {
     _errorHandler = errorHandler;
   }
 
   void _closePort(ReceivePort port) {
     if (port !== null) {
       port.close();
     }
   }
 
   String get path() { return _path; }
 
   int _exists(String path) native "Directory_Exists";
   bool _create(String path) native "Directory_Create";
   bool _delete(String path) native "Directory_Delete";
 
   var _dirHandler;
   var _fileHandler;
   var _doneHandler;
+  var _createTempHandler;
   var _errorHandler;
 
   String _path;
 }