/*
 * This file is part of the LibreOffice project.
 *
 * 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/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 .
 */

package ov;

import com.sun.star.accessibility.AccessibleEventObject;
import com.sun.star.accessibility.XAccessibleContext;
import com.sun.star.accessibility.XAccessibleEventBroadcaster;
import com.sun.star.accessibility.XAccessibleEventListener;
import com.sun.star.lang.EventObject;
import com.sun.star.uno.UnoRuntime;

/** Base class for object views that registers as accessibility event
    listener.
*/
abstract class ListeningObjectView
    extends ObjectView
    implements XAccessibleEventListener
{
    public ListeningObjectView (ObjectViewContainer aContainer)
    {
        super (aContainer);
    }

    /** Add this object as event listener at the broadcasting
        accessible object.
    */
    @Override
    public void SetObject (XAccessibleContext xContext)
    {
        super.SetObject (xContext);
        XAccessibleEventBroadcaster xBroadcaster =
            UnoRuntime.queryInterface(
            XAccessibleEventBroadcaster.class, xContext);
        if (xBroadcaster != null)
            xBroadcaster.addAccessibleEventListener (this);
    }


    /** Remove this object as event listener from the broadcasting
        accessible object.
    */
    @Override
    public void Destroy ()
    {
        super.Destroy ();
        XAccessibleEventBroadcaster xBroadcaster =
            UnoRuntime.queryInterface(
            XAccessibleEventBroadcaster.class, mxContext);
        if (xBroadcaster != null)
            xBroadcaster.removeAccessibleEventListener (this);
    }

    /** Derived classes have to implement this method to handle incoming
        events.
    */
    abstract public void notifyEvent (AccessibleEventObject aEvent);

    /** The disposing event is ignored per default.  If a derived class is
        interested it can overwrite this method.
    */
    public void disposing (EventObject aEvent)
    {
    }
}
