nsichannel.idl

linux下的一款播放器

/* -*- Mode: C++; tab-width: 4; 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 "nsIRequest.idl"

interface nsIURI;
interface nsIInterfaceRequestor;
interface nsIInputStream;
interface nsIStreamListener;

/**
 * The nsIChannel interface allows clients to construct "GET" requests for
 * specific protocols, and manage them in a uniform way.  Once a channel is
 * created (via nsIIOService::newChannel), parameters for that request may
 * be set by using the channel attributes, or by QI'ing to a subclass of
 * nsIChannel for protocol-specific parameters.  Then, the URI can be fetched
 * by calling nsIChannel::open or nsIChannel::asyncOpen.
 *
 * After a request has been completed, the channel is still valid for accessing
 * protocol-specific results.  For example, QI'ing to nsIHttpChannel allows
 * response headers to be retrieved for the corresponding http transaction. 
 *
 * @status FROZEN
 */
[scriptable, uuid(c63a055a-a676-4e71-bf3c-6cfa11082018)]
interface nsIChannel : nsIRequest
{
    /**
     * The original URI used to construct the channel. This is used in the case
     * of a redirect or URI "resolution" (e.g. resolving a resource: URI to a
     * file: URI) so that the original pre-redirect URI can still be obtained. 
     *
     * NOTE: this is distinctly different from the http Referer (referring URI),
     * which is typically the page that contained the original URI (accessible
     * from nsIHttpChannel).
     */
    attribute nsIURI originalURI;

    /**
     * The URI corresponding to the channel.  Its value is immutable.
     */
    readonly attribute nsIURI URI;

    /**
     * The owner, corresponding to the entity that is responsible for this
     * channel.  Used by the security manager to grant or deny privileges to
     * mobile code loaded from this channel.
     *
     * NOTE: this is a strong reference to the owner, so if the owner is also
     * holding a strong reference to the channel, care must be taken to 
     * explicitly drop its reference to the channel.
     */
    attribute nsISupports owner;

    /**
     * The notification callbacks for the channel.  This is set by clients, who
     * wish to provide a means to receive progress, status and protocol-specific 
     * notifications.  If this value is NULL, the channel implementation may use
     * the notification callbacks from its load group.
     * 
     * Interfaces commonly requested include: nsIProgressEventSink, nsIPrompt,
     * and nsIAuthPrompt.
     */
    attribute nsIInterfaceRequestor notificationCallbacks;

    /**
     * Transport-level security information (if any) corresponding to the channel.
     */
    readonly attribute nsISupports securityInfo;

    /**
     * The MIME type of the channel's content if available. 
     * 
     * NOTE: the content type can often be wrongly specified (e.g., wrong file
     * extension, wrong MIME type, wrong document type stored on a server, etc.),
     * and the caller most likely wants to verify with the actual data. 
     */
    attribute ACString contentType;

    /**
     * The character set of the channel's content if available and if applicable.
     * This attribute only applies to textual data.
     */
    attribute ACString contentCharset;

    /**
     * The length of the data associated with the channel if available.  A value
     * of -1 indicates that the content length is unknown.
     */
    attribute long contentLength;

    /**
     * Synchronously open the channel.
     *
     * @return blocking input stream to the channel's data.
     *
     * NOTE: nsIChannel implementations are not required to implement this
     * method.  Moreover, since this method may block the calling thread, it
     * should not be called on a thread that processes UI events.
     */
    nsIInputStream open();

    /**
     * Asynchronously open this channel.  Data is fed to the specified stream
     * listener as it becomes available.
     *
     * @param aListener the nsIStreamListener implementation
     * @param aContext an opaque parameter forwarded to aListener's methods
     */
    void asyncOpen(in nsIStreamListener aListener, in nsISupports aContext);

    /**************************************************************************
     * Channel specific load flags:
     *
     * Bits 20-31 are reserved for future use by this interface or one of its
     * derivatives (e.g., see nsICachingChannel).
     */

    /**
     * Set (e.g., by the docshell) to indicate whether or not the channel
     * corresponds to a document URI.
     */
    const unsigned long LOAD_DOCUMENT_URI = 1 << 16;

    /** 
     * If the end consumer for this load has been retargeted after discovering 
     * it's content, this flag will be set:
     */
    const unsigned long LOAD_RETARGETED_DOCUMENT_URI = 1 << 17;

    /**
     * This flag is set to indicate that onStopRequest may be followed by
     * another onStartRequest/onStopRequest pair.  This flag is, for example,
     * used by the multipart/replace stream converter.
     */
	const unsigned long LOAD_REPLACE = 1 << 18;

    /**
     * Set (e.g., by the docshell) to indicate whether or not the channel
     * corresponds to an initial document URI load (e.g., link click).
     */
    const unsigned long LOAD_INITIAL_DOCUMENT_URI = 1 << 19;
};