/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Mozilla browser.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications, Inc.  Portions created by Netscape are
 * Copyright (C) 1999, Mozilla.  All Rights Reserved.
 * 
 * Contributor(s):
 *   Travis Bogard <travis@netscape.com>
 */

#include "nsISupports.idl"

interface nsIDOMWindow;
interface nsIWebProgressListener;

/**
 * The nsIWebProgress interface is used to look at the progress of document
 * loading in a particular DOM Window.
 *
 * @status UNDER_REVIEW
 */

[scriptable, uuid(570F39D0-EFD0-11d3-B093-00A024FFC08C)]
interface nsIWebProgress : nsISupports
{
  /**
   * Registers a listener to be notified of Progress Events
   *
   * @param listener - The listener interface to be called when a progress
   *                   event occurs.
   *
   * @return  NS_OK - Listener was registered successfully.
   *          NS_INVALID_ARG - The listener passed in was either nsnull, 
   *                            or was already registered with this progress
   *                            interface.
   */
  void addProgressListener(in nsIWebProgressListener listener);

  /**
   * Removes a previously registered listener of Progress Events
   *
   * @param listener - The listener interface previously registered with 
   *                   AddListener().
   *
   * @return  NS_OK - Listener was successfully unregistered.
   *          NS_ERROR_INVALID_ARG - The listener was not previously
   *                                 registered listener.
   */
  void removeProgressListener(in nsIWebProgressListener listener);

  /**
   * The DOM Window associated with the WebProgress instance.
   */
  readonly attribute nsIDOMWindow DOMWindow;
};