/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 *
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 * Version 1.1 (the "License"); you may not use this file except in
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 *
 * 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.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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#include "nsISupports.idl"

interface nsIURIContentListener;
interface nsIURI;
interface nsILoadGroup;
interface nsIDocumentLoader;
interface nsIProgressEventSink;
interface nsIChannel;
interface nsIRequest;
interface nsIStreamListener;
interface nsIInputStream;

/**
 * The uri dispatcher is responsible for taking uri's, determining
 * the content and routing the opened url to the correct content 
 * handler. 
 *
 * When you encounter a url you want to open, you typically call 
 * openURI, passing it the content listener for the window the uri is 
 * originating from. The uri dispatcher opens the url to discover the 
 * content type. It then gives the content listener first crack at 
 * handling the content. If it doesn't want it, the dispatcher tries
 * to hand it off one of the registered content listeners. This allows
 * running applications the chance to jump in and handle the content.
 *
 * If that also fails, then the uri dispatcher goes to the registry
 * looking for the preferred content handler for the content type
 * of the uri. The content handler may create an app instance
 * or it may hand the contents off to a platform specific plugin
 * or helper app. Or it may hand the url off to an OS registered 
 * application. 
 */
[scriptable, uuid(40AECB53-8B65-11d3-989D-001083010E9B)]
interface nsIURILoader : nsISupports
{
  /**
   * As applications such as messenger and the browser are instantiated,
   * they register content listener's with the uri dispatcher corresponding
   * to content windows within that application. 
   *
   * Note to self: we may want to optimize things a bit more by requiring
   * the content types the registered content listener cares about.
   *
   * @param aContentListener the listener to register
   *
   * @see the nsIURILoader class description
   */
  void registerContentListener   (in nsIURIContentListener aContentListener);
  void unRegisterContentListener (in nsIURIContentListener aContentListener);

  /**
   * OpenURI requires the following parameters.....
   * @param aChannel
   *        The channel that should be opened. This must not be asyncOpen'd yet!
   * @param aIsContentPreferred
   *        Should the content be displayed in a container that prefers the
   *        content-type, or will any container do.
   * @param aWindowContext
   *        If you are running the url from a doc shell or a web shell, this is
   *        your window context. If you have a content listener you want to
   *        give first crack to, the uri loader needs to be able to get it
   *        from the window context (we'll use nsIInterfaceRequestor). We will
   *        also be using nsIInterfaceRequestor to get at the progress event
   *        sink interface.
   */ 
  void openURI(in nsIChannel aChannel,
               in boolean aIsContentPreferred,
               in nsISupports aWindowContext);


  /**
   * Stops an in progress load
   */
  void stop(in nsISupports aLoadCookie);
  
  /**
   * dirty little back door for sneaking the load group out in case you need 
   * it to create the channel before calling openURI
   */
  nsILoadGroup getLoadGroupForContext(in nsISupports aWindowContext);
  nsIDocumentLoader getDocumentLoaderForContext (in nsISupports aWindowContext);
};