win/idl/nsIInterfaceRequestor.idl

/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * 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 the Mozilla browser.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications, Inc.
 * Portions created by the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Travis Bogard <travis@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of 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 MPL, 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 MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"

/**
 * The nsIInterfaceRequestor interface defines a generic interface for 
 * requesting interfaces that a given object might provide access to.
 * This is very similar to QueryInterface found in nsISupports.  
 * The main difference is that interfaces returned from GetInterface()
 * are not required to provide a way back to the object implementing this 
 * interface.  The semantics of QI() dictate that given an interface A that 
 * you QI() on to get to interface B, you must be able to QI on B to get back 
 * to A.  This interface however allows you to obtain an interface C from A 
 * that may or most likely will not have the ability to get back to A. 
 *
 * @status FROZEN
 */

[scriptable, uuid(033A1470-8B2A-11d3-AF88-00A024FFC08C)]
interface nsIInterfaceRequestor : nsISupports
{
   /**
    * Retrieves the specified interface pointer.
    *
    * @param uuid The IID of the interface being requested.
    * @param result [out] The interface pointer to be filled in if
    *               the interface is accessible.
    * @return NS_OK - interface was successfully returned.
    *         NS_NOINTERFACE - interface not accessible.
    *         NS_ERROR* - method failure.
    */
	void getInterface(in nsIIDRef uuid, 
                      [iid_is(uuid),retval] out nsQIResult result);
};