win/idl/nsIRDFObserver.idl

/* -*- Mode: C++; tab-width: 4; 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.org code.
 *
 * 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):
 *
 * 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
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

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

interface nsIRDFDataSource;

// An nsIRDFObserver object is an observer that will be notified
// when assertions are made or removed from a datasource
[scriptable, uuid(3CC75360-484A-11D2-BC16-00805F912FE7)]
interface nsIRDFObserver : nsISupports {
    /**
     * This method is called whenever a new assertion is made
     * in the data source
     * @param aDataSource the datasource that is issuing
     *   the notification.
     * @param aSource the subject of the assertion
     * @param aProperty the predicate of the assertion
     * @param aTarget the object of the assertion
     */
    void onAssert(in nsIRDFDataSource aDataSource,
                  in nsIRDFResource aSource,
                  in nsIRDFResource aProperty,
                  in nsIRDFNode     aTarget);

    /**
     * This method is called whenever an assertion is removed
     * from the data source
     * @param aDataSource the datasource that is issuing
     *   the notification.
     * @param aSource the subject of the assertion
     * @param aProperty the predicate of the assertion
     * @param aTarget the object of the assertion
     */
    void onUnassert(in nsIRDFDataSource aDataSource,
                    in nsIRDFResource aSource,
                    in nsIRDFResource aProperty,
                    in nsIRDFNode     aTarget);

    /**
     * This method is called when the object of an assertion
     * changes from one value to another.
     * @param aDataSource the datasource that is issuing
     *   the notification.
     * @param aSource the subject of the assertion
     * @param aProperty the predicate of the assertion
     * @param aOldTarget the old object of the assertion
     * @param aNewTarget the new object of the assertion
     */
    void onChange(in nsIRDFDataSource aDataSource,
                  in nsIRDFResource aSource,
                  in nsIRDFResource aProperty,
                  in nsIRDFNode     aOldTarget,
                  in nsIRDFNode     aNewTarget);

    /**
     * This method is called when the subject of an assertion
     * changes from one value to another.
     * @param aDataSource the datasource that is issuing
     *   the notification.
     * @param aOldSource the old subject of the assertion
     * @param aNewSource the new subject of the assertion
     * @param aProperty the predicate of the assertion
     * @param aTarget the object of the assertion
     */
    void onMove(in nsIRDFDataSource aDataSource,
                in nsIRDFResource aOldSource,
                in nsIRDFResource aNewSource,
                in nsIRDFResource aProperty,
                in nsIRDFNode     aTarget);

    /**
     * This method is called when a datasource is about to
     * send several notifications at once. The observer can
     * use this as a cue to optimize its behavior. The observer
     * can expect the datasource to call endUpdateBatch() when
     * the group of notifications has completed.
     * @param aDataSource the datasource that is going to
     *   be issuing the notifications.
     */
    void onBeginUpdateBatch(in nsIRDFDataSource aDataSource);

    /**
     * This method is called when a datasource has completed
     * issuing a notification group.
     * @param aDataSource the datasource that has finished
     *   issuing a group of notifications
     */
    void onEndUpdateBatch(in nsIRDFDataSource aDataSource);
};