/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

/**
 * The interface for the callback invoked when there is an error.
 */
[scriptable, function, uuid(5DAEDDC3-FC94-4880-8A4F-26D910B92662)]
interface nsINativeFileWatcherErrorCallback: nsISupports
{
  /**
   * @param xpcomError The XPCOM error code.
   * @param osError The native OS error (errno under Unix, GetLastError under Windows).
   */
  void complete(in nsresult xpcomError, in long osError);
};

/**
 * The interface for the callback invoked when a change on a watched
 * resource is detected.
 */
[scriptable, function, uuid(FE4D86C9-243F-4195-B544-AECE3DF4B86A)]
interface nsINativeFileWatcherCallback: nsISupports
{
  /**
   * @param resourcePath
   *        The path of the changed resource. If there were too many changes,
   *        the string "*" is passed.
   * @param flags Reserved for future uses, not currently used.
   */
  void changed(in AString resourcePath, in int32_t flags);
};

/**
 * The interface for the callback invoked when a file watcher operation
 * successfully completes.
 */
[scriptable, function, uuid(C3D7F542-681B-4ABD-9D65-9D799B29A42B)]
interface nsINativeFileWatcherSuccessCallback: nsISupports
{
  /**
   * @param resourcePath
   *        The path of the resource for which the operation completes.
   */
  void complete(in AString resourcePath);
};

/**
 * A service providing native implementations of path changes notification.
 */
[scriptable, builtinclass, uuid(B3A4E8D8-7DC8-47DB-A8B4-83736D7AC1AA)]
interface nsINativeFileWatcherService: nsISupports
{
  /**
   * Watches the passed path for changes. If it's a directory, every file
   * it contains is watched. Recursively watches subdirectories. If the
   * resource is already being watched, does nothing. If the passed path
   * is a file, the behaviour is not specified.
   *
   * @param pathToWatch The path to watch for changes.
   * @param onChange
   *        The callback invoked whenever a change on a watched
   *        resource is detected.
   * @param onError
   *        The optional callback invoked whenever an error occurs.
   * @param onSuccess
   *        The optional callback invoked when the file watcher starts
   *        watching the resource for changes.
   */
  void addPath(in AString pathToWatch,
               in nsINativeFileWatcherCallback onChange,
               [optional] in nsINativeFileWatcherErrorCallback onError,
               [optional] in nsINativeFileWatcherSuccessCallback onSuccess);

  /**
   * Removes the provided path from the watched resources. If the path
   * was not being watched or the callbacks were not registered, silently
   * ignores the request.
   * Please note that the file watcher only considers the onChange callbacks
   * when deciding to close a watch on a resource. If there are no more onChange
   * callbacks associated to the watch, it gets closed (even though it still has
   * some error callbacks associated).
   *
   * @param pathToUnwatch The path to un-watch.
   * @param onChange
   *        The registered callback invoked whenever a change on a watched
   *        resource is detected.
   * @param onError
   *        The optionally registered callback invoked whenever an error
   *        occurs.
   * @param onSuccess
   *        The optional callback invoked when the file watcher stops
   *        watching the resource for changes.
   */
  void removePath(in AString pathToUnwatch,
                  in nsINativeFileWatcherCallback onChange,
                  [optional] in nsINativeFileWatcherErrorCallback onError,
                  [optional] in nsINativeFileWatcherSuccessCallback onSuccess);
};


%{ C++

#define NATIVE_FILEWATCHER_SERVICE_CID {0x6F488507, 0x469D, 0x4350, {0xA6, 0x8D, 0x99, 0xC8, 0x7, 0xBE, 0xA, 0x78}}
#define NATIVE_FILEWATCHER_SERVICE_CONTRACTID "@mozilla.org/toolkit/filewatcher/native-file-watcher;1"

%}
