/*

 * Copyright (c) 2008, 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 sun.awt;

import java.awt.AWTEvent;

import java.awt.EventQueue;

public class EventQueueDelegate {

    private static final Object EVENT_QUEUE_DELEGATE_KEY =

        new StringBuilder("EventQueueDelegate.Delegate");

    public static void setDelegate(Delegate delegate) {

        AppContext.getAppContext().put(EVENT_QUEUE_DELEGATE_KEY, delegate);

    }

    public static Delegate getDelegate() {

        return

          (Delegate) AppContext.getAppContext().get(EVENT_QUEUE_DELEGATE_KEY);

    }

    public interface Delegate {

        /**

         * This method allows for changing {@code EventQueue} events order.

         *

         * @param eventQueue current {@code EventQueue}

         * @return next {@code event} for the {@code EventDispatchThread}

         */

        public AWTEvent getNextEvent(EventQueue eventQueue) throws InterruptedException;

        /**

         * Notifies delegate before EventQueue.dispatch method.

         *

         * Note: this method may mutate the event

         *

         * @param event  to be dispatched by {@code dispatch} method

         * @return handle to be passed to {@code afterDispatch} method

         */

        public Object beforeDispatch(AWTEvent event) throws InterruptedException;

        /**

         * Notifies delegate after EventQueue.dispatch method.

         *

         * @param event {@code event} dispatched by the {@code dispatch} method

         * @param handle object which came from {@code beforeDispatch} method

         */

        public void afterDispatch(AWTEvent event, Object handle) throws InterruptedException;

    }

}