/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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) 1998
 * 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 ***** */

#include "nsISupports.idl"

interface nsIURI;
interface nsIRequest;

/**
 * nsIProgressEventSink
 *
 * This interface is used to asynchronously convey channel status and progress
 * information that is generally not critical to the processing of the channel.
 * The information is intended to be displayed to the user in some meaningful
 * way.
 *
 * An implementation of this interface can be passed to a channel via the
 * channel's notificationCallbacks attribute.  See nsIChannel for more info.
 *
 * The channel will begin passing notifications to the progress event sink
 * after its asyncOpen method has been called.  Notifications will cease once
 * the channel calls its listener's onStopRequest method or once the channel
 * is canceled (via nsIRequest::cancel).
 *
 * NOTE: This interface is actually not specific to channels and may be used
 * with other implementations of nsIRequest.
 *
 * @status UNDER_REVIEW
 */
[scriptable, uuid(dd47ee00-18c2-11d3-9337-00104ba0fd40)]
interface nsIProgressEventSink : nsISupports
{
    /**
     * Called to notify the event sink that progress has occurred for the
     * given request.
     *
     * @param aRequest
     *        the request being observed (may QI to nsIChannel).
     * @param aContext
     *        if aRequest is a channel, then this parameter is the listener
     *        context passed to nsIChannel::asyncOpen.
     * @param aProgress
     *        numeric value in the range 0 to aProgressMax indicating the
     *        number of bytes transfered thus far.
     * @param aProgressMax
     *        numeric value indicating maximum number of bytes that will be
     *        transfered (or 0xFFFFFFFF if total is unknown).
     */
    void onProgress(in nsIRequest aRequest,
                    in nsISupports aContext,
                    in unsigned long aProgress,
                    in unsigned long aProgressMax);

    /**
     * Called to notify the event sink with a status message for the given
     * request.
     *
     * @param aRequest
     *        the request being observed (may QI to nsIChannel).
     * @param aContext
     *        if aRequest is a channel, then this parameter is the listener
     *        context passed to nsIChannel::asyncOpen.
     * @param aStatus
     *        status code (not necessarily an error code) indicating the
     *        state of the channel (usually the state of the underlying
     *        transport).  see nsISocketTransport for socket specific status
     *        codes.
     * @param aStatusArg
     *        status code argument to be used with the string bundle service
     *        to convert the status message into localized, human readable
     *        text.  the meaning of this parameter is specific to the value
     *        of the status code.  for socket status codes, this parameter
     *        indicates the host:port associated with the status code.
     */
    void onStatus(in nsIRequest aRequest,
                  in nsISupports aContext,
                  in nsresult aStatus,
                  in wstring aStatusArg);

};
