gecko-dev/xpcom/components/nsIClassInfo.idl

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** 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 Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * 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):
 *   John Bandhauer <jband@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
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 * the provisions above, a recipient may use your version of this file under
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 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"

%{C++
/**
 * Calling QueryInterface with this special IID will return a null-terminated
 * table of QITableEntry's. Not all objects support this.
 * Note that this breaks XPCOM rules a bit (the table doesn't derive from
 * nsISupports).
 */
#define NS_THISPTROFFSETS_SID \
    { 0x23e017cc, 0x5d6f, 0x430c, \
      { 0xb3, 0xe6, 0x9d, 0x32, 0x65, 0x70, 0xd6, 0xb8 } }
%}

/**
 * Provides information about a specific implementation class
 */

[scriptable, uuid(986c11d0-f340-11d4-9075-0010a4e73d9a)]
interface nsIClassInfo : nsISupports
{
    /**
     * Get an ordered list of the interface ids that instances of the class 
     * promise to implement. Note that nsISupports is an implicit member 
     * of any such list and need not be included. 
     *
     * Should set *count = 0 and *array = null and return NS_OK if getting the 
     * list is not supported.
     */
    void getInterfaces(out PRUint32 count, 
                       [array, size_is(count), retval] out nsIIDPtr array);

    /**
     * Get a language mapping specific helper object that may assist in using
     * objects of this class in a specific lanaguage. For instance, if asked
     * for the helper for nsIProgrammingLanguage::JAVASCRIPT this might return 
     * an object that can be QI'd into the nsIXPCScriptable interface to assist 
     * XPConnect in supplying JavaScript specific behavior to callers of the 
     * instance object.
     *
     * see: nsIProgrammingLanguage.idl
     *
     * Should return null if no helper available for given language.
     */
    nsISupports getHelperForLanguage(in PRUint32 language);

    /**
     * A contract ID through which an instance of this class can be created
     * (or accessed as a service, if |flags & SINGLETON|), or null.
     */
    readonly attribute string   contractID;

    /**
     * A human readable string naming the class, or null.
     */
    readonly attribute string   classDescription;

    /**
     * A class ID through which an instance of this class can be created
     * (or accessed as a service, if |flags & SINGLETON|), or null.
     */
    readonly attribute nsCIDPtr classID;

    /**
     * Return language type from list in nsIProgrammingLanguage
     */

    readonly attribute PRUint32 implementationLanguage;

    /**
     * Bitflags for 'flags' attribute.
     */
    const PRUint32 SINGLETON            = 1 << 0;
    const PRUint32 THREADSAFE           = 1 << 1;
    const PRUint32 MAIN_THREAD_ONLY     = 1 << 2;
    const PRUint32 DOM_OBJECT           = 1 << 3;
    const PRUint32 PLUGIN_OBJECT        = 1 << 4;

    /**
     * 'flags' attribute bitflag: whether objects of this type implement
     * nsIContent.
     */
    const PRUint32 CONTENT_NODE         = 1 << 6;
    
    // The high order bit is RESERVED for consumers of these flags. 
    // No implementor of this interface should ever return flags 
    // with this bit set.
    const PRUint32 RESERVED             = 1 << 31;


    readonly attribute PRUint32 flags;

    /**
     * Also a class ID through which an instance of this class can be created
     * (or accessed as a service, if |flags & SINGLETON|).  If the class does
     * not have a CID, it should return NS_ERROR_NOT_AVAILABLE.  This attribute
     * exists so C++ callers can avoid allocating and freeing a CID, as would
     * happen if they used classID.
     */
    [notxpcom] readonly attribute nsCID classIDNoAlloc;

};