001/*
002 * GWTEventService
003 * Copyright (c) 2011 and beyond, strawbill UG (haftungsbeschr?nkt)
004 *
005 * This is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU Lesser General Public License as
007 * published by the Free Software Foundation; either version 3 of
008 * the License, or (at your option) any later version.
009 * Other licensing for GWTEventService may also be possible on request.
010 * Please view the license.txt of the project for more information.
011 *
012 * This software is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this software; if not, write to the Free
019 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021 */
022package de.novanic.eventservice.client.command;
023
024import com.google.gwt.user.client.rpc.AsyncCallback;
025import de.novanic.eventservice.client.event.service.EventServiceAsync;
026
027/**
028 * A RemoteCommand can be used to execute a call from client to the server side. The possibility to queue RemoteCommands
029 * is one of the advantages.
030 *
031 * @author sstrohschein
032 * <br>Date: 06.06.2008
033 * <br>Time: 22:38:48
034 */
035public interface RemoteCommand<T>
036{
037    /**
038     * Initializes the RemoteCommand with a callback, which can also be used in the execute method
039     * {@link de.novanic.eventservice.client.command.RemoteCommand#execute(de.novanic.eventservice.client.event.service.EventServiceAsync)}
040     * @param aCallback callback
041     */
042    void init(AsyncCallback<T> aCallback);
043
044    /**
045     * Checks if the RemoteCommand is initialized with a callback.
046     * @return true when the init method ({@link de.novanic.eventservice.client.command.RemoteCommand#init(com.google.gwt.user.client.rpc.AsyncCallback)})
047     * was called with a callback, false when the RemoteCommand wasn't initialized with a callback.
048     */
049    boolean isInitialized();
050
051    /**
052     * This method executes the RemoteCommand. This method has access to {@link de.novanic.eventservice.client.event.service.EventService}
053     * and to the initialized callback ({@link de.novanic.eventservice.client.command.RemoteCommand#getCallback()}).
054     * @param anEventService {@link de.novanic.eventservice.client.event.service.EventService}
055     */
056    void execute(EventServiceAsync anEventService);
057
058    /**
059     * Returns the callback, which can be set with the link method
060     * ({@link de.novanic.eventservice.client.command.RemoteCommand#init(com.google.gwt.user.client.rpc.AsyncCallback)})
061     * @return callback
062     */
063    AsyncCallback<T> getCallback();
064}