nsiuricontentlistener.idl

linux下的一款播放器

/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape 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/NPL/
 *
 * 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.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or 
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the NPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/**
 * nsIURIContentListener is an interface used by components which
 * want to know (and have a chance to handle) a particular content type.
 * Typical usage scenarios will include running applications which register
 * a nsIURIContentListener for each of its content windows with the uri
 * dispatcher service. 
 *
 * @status FROZEN
 */

#include "nsISupports.idl"

interface nsIRequest;
interface nsIStreamListener;
interface nsIURI;

[scriptable, uuid(94928AB3-8B63-11d3-989D-001083010E9B)]
interface nsIURIContentListener : nsISupports
{
 /**
  * Gives the original content listener first crack at stopping a load before
  * it happens.
  *
  * @param aURI   URI that is being opened.
  *
  * @return       <code>true</code> if the load can continue;
  *               <code>false</code> if the open should be aborted.
  */
  boolean onStartURIOpen(in nsIURI aURI);

 /**
  * Notifies the content listener to hook up an nsIStreamListener capable of
  * consuming the data stream.
  *
  * @param aContentType         Content type of the data.
  * @param aIsContentPreferred  Indicates whether the content should be
  *                             preferred by this listener.
  * @param aRequest             Request that is providing the data.
  * @param aContentHandler      nsIStreamListener that will consume the data.
  *                             This should be set to <code>nsnull</code> if
  *                             no consumer can handle the content type.
  *
  * @return                     <code>true</code> if the consumer wants to
  *                             handle the load completely by itself.  This
  *                             causes the URI Loader do nothing else...
  *                             <code>false</code> if the URI Loader should
  *                             continue handling the load.
  */
  boolean doContent(in string aContentType,
                    in boolean aIsContentPreferred,
                    in nsIRequest aRequest,
                    out nsIStreamListener aContentHandler);

 /*
  * When given a uri to dispatch, if the URI is specified as 'preferred 
  * content' then the uri loader tries to find a preferred content handler
  * for the content type. The thought is that many content listeners may
  * be able to handle the same content type if they have to. i.e. the mail
  * content window can handle text/html just like a browser window content
  * listener. However, if the user clicks on a link with text/html content,
  * then the browser window should handle that content and not the mail
  * window where the user may have clicked the link.  This is the difference
  * between isPreferred and canHandleContent.
  *
  * @param aContentType         Content type of the data.
  * @param aDesiredContentType  Indicates that aContentType must be converted
  *                             to aDesiredContentType before processing the
  *                             data.  This causes a stream converted to be
  *                             inserted into the nsIStreamListener chain.
  *                             This argument can be <code>nsnull</code> if
  *                             the content should be consumed directly as
  *                             aContentType.
  *
  * @return                     <code>true</code> if this is a preferred
  *                             content handler for aContentType;
  *                             <code>false<code> otherwise.
  */
  boolean isPreferred(in string aContentType, out string aDesiredContentType);

 /**
  * When given a uri to dispatch, if the URI is not specified as 'preferred
  * content' then the uri loader calls canHandleContent to see if the content
  * listener is capable of handling the content.
  *
  * @param aContentType         Content type of the data.
  * @param aIsContentPreferred  Indicates whether the content should be
  *                             preferred by this listener.
  * @param aDesiredContentType  Indicates that aContentType must be converted
  *                             to aDesiredContentType before processing the
  *                             data.  This causes a stream converted to be
  *                             inserted into the nsIStreamListener chain.
  *                             This argument can be <code>nsnull</code> if
  *                             the content should be consumed directly as
  *                             aContentType.
  *
  * @return                     <code>true</code> if the data can be consumed.
  *                             <code>false</code> otherwise.
  *
  * Note: I really envision canHandleContent as a method implemented
  * by the docshell as the implementation is generic to all doc
  * shells. The isPreferred decision is a decision made by a top level
  * application content listener that sits at the top of the docshell
  * hiearchy.
  */
  boolean canHandleContent(in string aContentType, 
                           in boolean aIsContentPreferred, 
                           out string aDesiredContentType);

 /**
  * The load context associated with a particular content listener.
  * The URI Loader stores and accesses this value as needed.
  */
  attribute nsISupports loadCookie;

 /**
  * The parent content listener if this particular listener is part of a chain
  * of content listeners (i.e. a docshell!)
  */
  attribute nsIURIContentListener parentContentListener;
};