/*
 * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.java.accessibility.util;

import java.awt.*;
import java.util.EventListener;
import javax.accessibility.*;


The TopLevelWindowMulticaster class is used to maintain a list of
TopLevelWindowListener classes.  It is intended to be used primarily
for internal support in the EventQueueMonitor class, and is not intended
to be used by classes outside the Java Accessibility Utility package.
See Also:
EventQueueMonitor
EventQueueMonitor.addTopLevelWindowListener
EventQueueMonitor.removeTopLevelWindowListener/**
 * The TopLevelWindowMulticaster class is used to maintain a list of
 * TopLevelWindowListener classes.  It is intended to be used primarily
 * for internal support in the EventQueueMonitor class, and is not intended
 * to be used by classes outside the Java Accessibility Utility package.
 *
 * @see EventQueueMonitor
 * @see EventQueueMonitor#addTopLevelWindowListener
 * @see EventQueueMonitor#removeTopLevelWindowListener
 *
 */
class TopLevelWindowMulticaster
    extends AWTEventMulticaster implements TopLevelWindowListener
{
    protected TopLevelWindowMulticaster(EventListener a, EventListener b) {
        super(a, b);
    }

    public void topLevelWindowCreated(Window w) {
        ((TopLevelWindowListener)a).topLevelWindowCreated(w);
        ((TopLevelWindowListener)b).topLevelWindowCreated(w);
    }

    public void topLevelWindowDestroyed(Window w) {
        ((TopLevelWindowListener)a).topLevelWindowDestroyed(w);
        ((TopLevelWindowListener)b).topLevelWindowDestroyed(w);
    }

    public static TopLevelWindowListener add(TopLevelWindowListener a, TopLevelWindowListener b) {
        return (TopLevelWindowListener)addInternal(a, b);
    }

    public static TopLevelWindowListener remove(TopLevelWindowListener l, TopLevelWindowListener oldl) {
        return (TopLevelWindowListener)removeInternal(l, oldl);
    }

    protected static EventListener addInternal(EventListener a, EventListener b) {
        if (a == null)  return b;
        if (b == null)  return a;
        return new TopLevelWindowMulticaster(a, b);
    }

    protected static EventListener removeInternal(EventListener l, EventListener oldl) {
        if (l == oldl || l == null) {
            return null;
        } else if (l instanceof TopLevelWindowMulticaster) {
            return ((TopLevelWindowMulticaster)l).remove(oldl);
        } else {
            return l;           // it's not here
        }
    }

}