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.connection.strategy.connector.streaming.specific;
023
024import com.google.gwt.dom.client.Element;
025import com.google.gwt.user.client.ui.Frame;
026import com.google.gwt.user.client.ui.RootPanel;
027import de.novanic.eventservice.client.connection.strategy.connector.streaming.GWTStreamingClientConnector;
028
029/**
030 * The {@link de.novanic.eventservice.client.connection.strategy.connector.ConnectionStrategyClientConnector} listens for occurred events ({@link de.novanic.eventservice.client.event.Event})
031 * of the server side and has the task to encode / process the transferred events at the client side.
032 *
033 * The {@link de.novanic.eventservice.client.connection.strategy.connector.streaming.specific.GWTStreamingClientConnectorGecko} is a
034 * Gecko / FF specific implementation of {@link de.novanic.eventservice.client.connection.strategy.connector.streaming.GWTStreamingClientConnector} which
035 * contains a special implementation to avoid loading messages / animations while streaming.
036 *
037 * @author sstrohschein
038 *         <br>Date: 07.05.2010
039 *         <br>Time: 23:29:33
040 */
041public class GWTStreamingClientConnectorGecko extends GWTStreamingClientConnector
042{
043    private static final Element DUMMY_FRAME_ELEMENT;
044
045    static {
046        DUMMY_FRAME_ELEMENT = createFrameElement();
047    }
048
049    private static Element createFrameElement() {
050        Frame theDummyFrame = new Frame();
051        theDummyFrame.setVisible(false);
052        final Element theDummyFrameElement = theDummyFrame.getElement();
053        theDummyFrameElement.setId("gwteventservice_dummy_frame");
054        return theDummyFrameElement;
055    }
056
057    /**
058     * That method can be used by a concrete implementation to sent received events. It de-serializes the event
059     * and notifies the callback and the {@link de.novanic.eventservice.client.event.listener.EventNotification} about the occurred
060     * event, itself. The callback is notified about events when the cycle ({@link de.novanic.eventservice.client.connection.strategy.connector.streaming.DefaultStreamingClientConnector#CYCLE_TAG})
061     * is triggered.
062     *
063     * That implementation creates a dummy frame to avoid loading messages / animation while streaming.
064     * @param anEvent event or cycle tag ({@link de.novanic.eventservice.client.connection.strategy.connector.streaming.DefaultStreamingClientConnector#CYCLE_TAG})
065     */
066    public void receiveEvent(String anEvent) {
067        //Gecko / FF hack start (avoid loading messages)
068                RootPanel.getBodyElement().appendChild(DUMMY_FRAME_ELEMENT);
069                RootPanel.getBodyElement().removeChild(DUMMY_FRAME_ELEMENT);
070        //Gecko / FF hack end (avoid loading messages)
071        super.receiveEvent(anEvent);
072    }
073}