/* -*- Mode: C++; tab-width: 4; 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.org code.
 *
 * 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): 
 */

#include "nsISupports.idl"
#include "nsIRDFDataSource.idl"
#include "nsIRDFResource.idl"
#include "nsIRDFNode.idl"
#include "nsIEnumerator.idl"

// A wrapper for manipulating RDF containers
[scriptable, uuid(D4214E90-FB94-11D2-BDD8-00104BDE6048)]
interface nsIRDFContainer : nsISupports {
    readonly attribute nsIRDFDataSource DataSource;
    readonly attribute nsIRDFResource   Resource;

    /**
     * Initialize the container wrapper to the specified resource
     * using the specified datasource for context.
     */
    void Init(in nsIRDFDataSource aDataSource, in nsIRDFResource aContainer);

    /**
     * Return the number of elements in the container. Note that this
     * may not always be accurate due to aggregation.
     */
    long GetCount();

    /**
     * Return an enumerator that can be used to enumerate the contents
     * of the container in ascending order.
     */
    nsISimpleEnumerator GetElements();

    /**
     * Append an element to the container, assigning it the next
     * available ordinal.
     */
    void AppendElement(in nsIRDFNode aElement);

    /**
     * Remove the first occurence of the specified element from the
     * container. If aRenumber is 'true'
     */
    void RemoveElement(in nsIRDFNode aElement, in boolean aRenumber);

    /**
     * Insert aElement at the specified index. If aRenumber is 'true', then
     * the underlying RDF graph will be 're-numbered' to accomodate the new
     * element.
     */
    void InsertElementAt(in nsIRDFNode aElement, in long aIndex, in boolean aRenumber);

    /**
     * Remove the element at the specified index. If aRenumber is 'true', then
     * the underlying RDF graph will be 're-numbered' to accomodate the new
     * element.
     *
     * @return the element that was removed.
     */
    nsIRDFNode RemoveElementAt(in long aIndex, in boolean aRenumber);

    /**
     * Determine the index of an element in the container.
     *
     * @return The index of the specified element in the container. If
     * the element is not contained in the container, this function
     * returns '-1'.
     */
    long IndexOf(in nsIRDFNode aElement);
};

%{C++
nsresult
NS_NewRDFContainer(nsIRDFContainer** aResult);

nsresult
NS_NewRDFContainer(nsIRDFDataSource* aDataSource,
                   nsIRDFResource* aResource,
                   nsIRDFContainer** aResult);

/**
 * Create a cursor on a container that enumerates its contents in
 * order
 */
nsresult
NS_NewContainerEnumerator(nsIRDFDataSource* aDataSource,
                          nsIRDFResource* aContainer,
                          nsISimpleEnumerator** aResult);


%}