michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsISupports.idl"
michael@0: #include "nsIRDFResource.idl"
michael@0: #include "nsIRDFNode.idl"
michael@0: 
michael@0: interface nsIRDFDataSource;
michael@0: 
michael@0: // An nsIRDFObserver object is an observer that will be notified
michael@0: // when assertions are made or removed from a datasource
michael@0: [scriptable, uuid(3CC75360-484A-11D2-BC16-00805F912FE7)]
michael@0: interface nsIRDFObserver : nsISupports {
michael@0:     /**
michael@0:      * This method is called whenever a new assertion is made
michael@0:      * in the data source
michael@0:      * @param aDataSource the datasource that is issuing
michael@0:      *   the notification.
michael@0:      * @param aSource the subject of the assertion
michael@0:      * @param aProperty the predicate of the assertion
michael@0:      * @param aTarget the object of the assertion
michael@0:      */
michael@0:     void onAssert(in nsIRDFDataSource aDataSource,
michael@0:                   in nsIRDFResource aSource,
michael@0:                   in nsIRDFResource aProperty,
michael@0:                   in nsIRDFNode     aTarget);
michael@0: 
michael@0:     /**
michael@0:      * This method is called whenever an assertion is removed
michael@0:      * from the data source
michael@0:      * @param aDataSource the datasource that is issuing
michael@0:      *   the notification.
michael@0:      * @param aSource the subject of the assertion
michael@0:      * @param aProperty the predicate of the assertion
michael@0:      * @param aTarget the object of the assertion
michael@0:      */
michael@0:     void onUnassert(in nsIRDFDataSource aDataSource,
michael@0:                     in nsIRDFResource aSource,
michael@0:                     in nsIRDFResource aProperty,
michael@0:                     in nsIRDFNode     aTarget);
michael@0: 
michael@0:     /**
michael@0:      * This method is called when the object of an assertion
michael@0:      * changes from one value to another.
michael@0:      * @param aDataSource the datasource that is issuing
michael@0:      *   the notification.
michael@0:      * @param aSource the subject of the assertion
michael@0:      * @param aProperty the predicate of the assertion
michael@0:      * @param aOldTarget the old object of the assertion
michael@0:      * @param aNewTarget the new object of the assertion
michael@0:      */
michael@0:     void onChange(in nsIRDFDataSource aDataSource,
michael@0:                   in nsIRDFResource aSource,
michael@0:                   in nsIRDFResource aProperty,
michael@0:                   in nsIRDFNode     aOldTarget,
michael@0:                   in nsIRDFNode     aNewTarget);
michael@0: 
michael@0:     /**
michael@0:      * This method is called when the subject of an assertion
michael@0:      * changes from one value to another.
michael@0:      * @param aDataSource the datasource that is issuing
michael@0:      *   the notification.
michael@0:      * @param aOldSource the old subject of the assertion
michael@0:      * @param aNewSource the new subject of the assertion
michael@0:      * @param aProperty the predicate of the assertion
michael@0:      * @param aTarget the object of the assertion
michael@0:      */
michael@0:     void onMove(in nsIRDFDataSource aDataSource,
michael@0:                 in nsIRDFResource aOldSource,
michael@0:                 in nsIRDFResource aNewSource,
michael@0:                 in nsIRDFResource aProperty,
michael@0:                 in nsIRDFNode     aTarget);
michael@0: 
michael@0:     /**
michael@0:      * This method is called when a datasource is about to
michael@0:      * send several notifications at once. The observer can
michael@0:      * use this as a cue to optimize its behavior. The observer
michael@0:      * can expect the datasource to call endUpdateBatch() when
michael@0:      * the group of notifications has completed.
michael@0:      * @param aDataSource the datasource that is going to
michael@0:      *   be issuing the notifications.
michael@0:      */
michael@0:     void onBeginUpdateBatch(in nsIRDFDataSource aDataSource);
michael@0: 
michael@0:     /**
michael@0:      * This method is called when a datasource has completed
michael@0:      * issuing a notification group.
michael@0:      * @param aDataSource the datasource that has finished
michael@0:      *   issuing a group of notifications
michael@0:      */
michael@0:     void onEndUpdateBatch(in nsIRDFDataSource aDataSource);
michael@0: };