/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface nsILoadGroup;

/**
 * nsILoadGroupChild provides a hierarchy of load groups so that the
 * root load group can be used to conceptually tie a series of loading
 * operations into a logical whole while still leaving them separate
 * for the purposes of cancellation and status events.
 */

[builtinclass, scriptable, uuid(02efe8e2-fbbc-4718-a299-b8a09c60bf6b)]
interface nsILoadGroupChild : nsISupports
{
    /**
     * The parent of this load group. It is stored with
     * a nsIWeakReference/nsWeakPtr so there is no requirement for the
     * parentLoadGroup to out live the child, nor will the child keep a
     * reference count on the parent.
     */
    attribute nsILoadGroup parentLoadGroup;

    /**
     * The nsILoadGroup associated with this nsILoadGroupChild
     */
    readonly attribute nsILoadGroup childLoadGroup;

    /**
     * The rootLoadGroup is the recursive parent of this
     * load group where parent is defined as parentlLoadGroup if set
     * or childLoadGroup.loadGroup as a backup. (i.e. parentLoadGroup takes
     * precedence.) The nsILoadGroup child is the root if neither parent
     * nor loadgroup attribute is specified.
     */
    readonly attribute nsILoadGroup rootLoadGroup;
};