/* -*- Mode: C++; tab-width: 2; 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 Mozilla.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications.  Portions created by Netscape Communications are
 * Copyright (C) 2001 by Netscape Communications.  All
 * Rights Reserved.
 * 
 * Contributor(s): 
 *   Vidur Apparao <vidur@netscape.com> (original author)
 */

#include "nsISupports.idl"

interface nsIDocument;
interface nsIDOMHTMLScriptElement;
interface nsIScriptLoaderObserver;

[scriptable, uuid(501209d3-7edf-437d-9948-3c6d1c08ef7a)]
interface nsIScriptLoader : nsISupports {
  /**
   * Initialize loader with a document. The container of this document
   * will be used for getting script evaluation information, including
   * the context in which to do the evaluation. The loader maintains a 
   * strong reference to the document.
   *
   * @param aDocument The document to use as the basis for script
   *        processing.
   */
  void init(in nsIDocument aDocument);

  /**
   * The loader maintains a strong reference to the document with
   * which it is initialized. This call forces the reference to
   * be dropped.
   */
  void dropDocumentReference();

  /**
   * Add an observer for all scripts loaded through this loader.
   *
   * @param aObserver observer for all script processing.
   */
  void addObserver(in nsIScriptLoaderObserver aObserver);

  /**
   * Remove an observer.
   *
   * @param aObserver observer to be removed
   */
  void removeObserver(in nsIScriptLoaderObserver aObserver);
  
  /**
   * Process a script element. This will include both loading the 
   * source of the element if it is not inline and evaluating
   * the script itself.
   *
   * @param aElement The element representing the script to be loaded and
   *        evaluated.
   * @param aObserver An observer for this script load only
   *
   */
  void processScriptElement(in nsIDOMHTMLScriptElement aElement,
                            in nsIScriptLoaderObserver aObserver);

  /**
   * Suspend processing of new script elements. Any call to 
   * processScriptElement() will fail with a return code of
   * NS_ERROR_NOT_AVAILABLE. Note that this DOES NOT suspend
   * currently loading or executing scripts. All calls to 
   * suspend() must be matched with an equal number of calls 
   * to resume() before processing of new script elements 
   * continues. 
   */
  void suspend();

  /**
   * Resume processing of new script elements. 
   */
  void resume();
};