xpcom/base/nsIInterfaceRequestor.idl

   1 /* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is the Mozilla browser.
  17  *
  18  * The Initial Developer of the Original Code is
  19  * Netscape Communications, Inc.
  20  * Portions created by the Initial Developer are Copyright (C) 1999
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *   Travis Bogard <travis@netscape.com>
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either of the GNU General Public License Version 2 or later (the "GPL"),
  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
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  34  * and other provisions required by the GPL or the LGPL. If you do not delete
  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #include "nsISupports.idl"
  41
  42 /**
  43  * The nsIInterfaceRequestor interface defines a generic interface for
  44  * requesting interfaces that a given object might provide access to.
  45  * This is very similar to QueryInterface found in nsISupports.
  46  * The main difference is that interfaces returned from GetInterface()
  47  * are not required to provide a way back to the object implementing this
  48  * interface.  The semantics of QI() dictate that given an interface A that
  49  * you QI() on to get to interface B, you must be able to QI on B to get back
  50  * to A.  This interface however allows you to obtain an interface C from A
  51  * that may or most likely will not have the ability to get back to A.
  52  */
  53
  54 [scriptable, uuid(033A1470-8B2A-11d3-AF88-00A024FFC08C)]
  55 interface nsIInterfaceRequestor : nsISupports
  56 {
  57    /**
  58     * Retrieves the specified interface pointer.
  59     *
  60     * @param uuid The IID of the interface being requested.
  61     * @param result [out] The interface pointer to be filled in if
  62     *               the interface is accessible.
  63     * @return NS_OK - interface was successfully returned.
  64     *         NS_NOINTERFACE - interface not accessible.
  65     *         NS_ERROR* - method failure.
  66     */
  67         void getInterface(in nsIIDRef uuid,
  68                       [iid_is(uuid),retval] out nsQIResult result);
  69 };
  70