/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * 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 Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 *   John Bandhauer <jband@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU Public License (the "GPL"), in which case the
 * provisions of the GPL are applicable instead of those above.
 * If you wish to allow use of your version of this file only
 * under the terms of the GPL and not to allow others to use your
 * version of this file under the NPL, indicate your decision by
 * deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL.  If you do not delete
 * the provisions above, a recipient may use your version of this
 * file under either the NPL or the GPL.
 */

#include "nsISupports.idl"
#include "nsIProgrammingLanguage.idl"

/**
 * Provides information about a specific implementation class
 * @status FROZEN
 */

[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;
    const PRUint32 EAGER_CLASSINFO      = 1 << 5;
    /**
     * '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;

};
