Revert "Rename blahHandler to onBlah throughout dart:io."

runtime/bin/directory_impl.dart

 // Copyright (c) 2012, 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.
 
 
 // Used for holding error code and error message for failed OS system calls.
 class _OSStatus {
   int _errorCode;
   String _errorMessage;
 }
 
 
 class _Directory implements Directory {
   static final kCreateRequest = 0;
   static final kDeleteRequest = 1;
   static final kExistsRequest = 2;
   static final kCreateTempRequest = 3;
   static final kListRequest = 4;
 
   _Directory(String this._path);
 
   static String _createTemp(String template,
                             _OSStatus status) native "Directory_CreateTemp";
   static int _exists(String path) native "Directory_Exists";
   static bool _create(String path) native "Directory_Create";
   static bool _delete(String path, bool recursive) native "Directory_Delete";
   static SendPort _newServicePort() native "Directory_NewServicePort";
 
-  void exists(void callback(bool exists)) {
+  void exists() {
     if (_directoryService == null) {
       _directoryService = _newServicePort();
     }
     List request = new List(2);
     request[0] = kExistsRequest;
     request[1] = _path;
     _directoryService.call(request).receive((result, replyTo) {
+      var handler =
+          (_existsHandler != null) ? _existsHandler : (result) => null;
       if (result < 0) {
-        if (_onError != null) {
-          _onError("Diretory exists test failed: $_path");
+        if (_errorHandler != null) {
+          _errorHandler("Diretory exists test failed: $_path");
         }
       } else {
-        callback(result == 1);
+        handler(result == 1);
       }
     });
   }
 
   bool existsSync() {
     int exists = _exists(_path);
     if (exists < 0) {
       throw new DirectoryException("Diretory exists test failed: $_path");
     }
     return (exists == 1);
   }
 
-  void create(void callback()) {
+  void create() {
     if (_directoryService == null) {
       _directoryService = _newServicePort();
     }
     List request = new List(2);
     request[0] = kCreateRequest;
     request[1] = _path;
     _directoryService.call(request).receive((result, replyTo) {
       if (result) {
-        callback();
-      } else if (_onError != null) {
-        _onError("Directory creation failed: $_path");
+        if (_createHandler != null) _createHandler();
+      } else if (_errorHandler != null) {
+        _errorHandler("Directory creation failed: $_path");
       }
     });
   }
 
   void createSync() {
     if (!_create(_path)) {
       throw new DirectoryException("Directory creation failed: $_path");
     }
   }
 
-  void createTemp(void callback()) {
+  void createTemp() {
     if (_directoryService == null) {
       _directoryService = _newServicePort();
     }
     List request = new List(2);
     request[0] = kCreateTempRequest;
     request[1] = _path;
     _directoryService.call(request).receive((result, replyTo) {
       if (result is !List) {
         _path = result;
-        callback();
-      } else if (_onError != null) {
-        _onError("Could not create temporary directory [$_path]: " +
-                 "${result[1]}");
+        if (_createTempHandler != null) _createTempHandler();
+      } else if (_errorHandler != null) {
+        _errorHandler("Could not create temporary directory [$_path]: " +
+                      "${result[1]}");
       }
     });
   }
 
   void createTempSync() {
     var status = new _OSStatus();
     var result = _createTemp(path, status);
     if (result != null) {
       _path = result;
     } else {
       throw new DirectoryException(
           "Could not create temporary directory [$_path]: " +
           "${status._errorMessage}",
           status._errorCode);
     }
   }
 
-  void _deleteHelper(bool recursive, String errorMsg, void callback()) {
+  void delete([bool recursive = false]) {
     if (_directoryService == null) {
       _directoryService = _newServicePort();
     }
     List request = new List(3);
     request[0] = kDeleteRequest;
     request[1] = _path;
     request[2] = recursive;
     _directoryService.call(request).receive((result, replyTo) {
       if (result) {
-        callback();
-      } else if (_onError != null) {
-        _onError("${errorMsg}: $_path");
+        if (_deleteHandler != null) _deleteHandler();
+      } else if (_errorHandler != null) {
+        if (recursive) {
+          _errorHandler("Recursive directory deletion failed: $_path");
+        } else {
+          _errorHandler("Non-recursive directory deletion failed: $_path");
+        }
       }
     });
   }
 
-  void delete(void callback()) {
-    _deleteHelper(false, "Directory deletion failed", callback);
-  }
-
-  void deleteRecursively(void callback()) {
-    _deleteHelper(true, "Recursive directory deletion failed", callback);
-  }
-
-  void deleteSync() {
-    bool recursive = false;
+  void deleteSync([bool recursive = false]) {
     if (!_delete(_path, recursive)) {
       throw new DirectoryException("Directory deletion failed: $_path");
     }
   }
 
-  void deleteRecursivelySync() {
-    bool recursive = true;
-    if (!_delete(_path, recursive)) {
-      throw new DirectoryException(
-          "Recursive directory deletion failed: $_path");
-    }
-  }
-
   void list([bool recursive = false]) {
     final int kListDirectory = 0;
     final int kListFile = 1;
     final int kListError = 2;
     final int kListDone = 3;
 
     List request = new List(3);
     request[0] = kListRequest;
     request[1] = _path;
     request[2] = recursive;
     ReceivePort responsePort = new ReceivePort();
     // Use a separate directory service port for each listing as
     // listing operations on the same directory can run in parallel.
     _newServicePort().send(request, responsePort.toSendPort());
     responsePort.receive((message, replyTo) {
       if (message is !List || message[0] is !int) {
         responsePort.close();
-        if (_onError != null) _onError("Internal error");
+        if (_errorHandler != null) _errorHandler("Internal error");
         return;
       }
       switch (message[0]) {
         case kListDirectory:
-          if (_onDir != null) _onDir(message[1]);
+          if (_dirHandler != null) _dirHandler(message[1]);
           break;
         case kListFile:
-          if (_onFile != null) _onFile(message[1]);
+          if (_fileHandler != null) _fileHandler(message[1]);
           break;
         case kListError:
-          if (_onError != null) _onError(message[1]);
+          if (_errorHandler != null) _errorHandler(message[1]);
           break;
         case kListDone:
           responsePort.close();
-          if (_onDone != null) _onDone(message[1]);
+          if (_doneHandler != null) _doneHandler(message[1]);
           break;
       }
     });
   }
 
-  void set onDir(void onDir(String dir)) {
-    _onDir = onDir;
+  void set dirHandler(void dirHandler(String dir)) {
+    _dirHandler = dirHandler;
   }
 
-  void set onFile(void onFile(String file)) {
-    _onFile = onFile;
+  void set fileHandler(void fileHandler(String file)) {
+    _fileHandler = fileHandler;
   }
 
-  void set onDone(void onDone(bool completed)) {
-    _onDone = onDone;
+  void set doneHandler(void doneHandler(bool completed)) {
+    _doneHandler = doneHandler;
   }
 
-  void set onError(void onError(String error)) {
-    _onError = onError;
+  void set existsHandler(void existsHandler(bool exists)) {
+    _existsHandler = existsHandler;
+  }
+
+  void set createHandler(void createHandler()) {
+    _createHandler = createHandler;
+  }
+
+  void set createTempHandler(void createTempHandler()) {
+    _createTempHandler = createTempHandler;
+  }
+
+  void set deleteHandler(void deleteHandler()) {
+    _deleteHandler = deleteHandler;
+  }
+
+  void set errorHandler(void errorHandler(String error)) {
+    _errorHandler = errorHandler;
   }
 
   void _closePort(ReceivePort port) {
     if (port !== null) {
       port.close();
     }
   }
 
   String get path() { return _path; }
 
-  var _onDir;
-  var _onFile;
-  var _onDone;
-  var _onError;
+  var _dirHandler;
+  var _fileHandler;
+  var _doneHandler;
+  var _existsHandler;
+  var _createHandler;
+  var _createTempHandler;
+  var _deleteHandler;
+  var _errorHandler;
 
   String _path;
   SendPort _directoryService;
 }