001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library 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 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.ui.client;
029
030import org.opencms.ui.components.CmsPanel;
031
032import com.google.gwt.user.client.Timer;
033import com.vaadin.client.ApplicationConnection;
034import com.vaadin.client.UIDL;
035import com.vaadin.client.ui.panel.PanelConnector;
036import com.vaadin.shared.ui.Connect;
037
038/**
039 * Connector for the CmsPanel widget.<p>
040 *
041 * Contains a workaround for a glitch where the scroll position is sometimes reset after an RPC call.<p>
042 */
043@Connect(CmsPanel.class)
044public class CmsPanelConnector extends PanelConnector {
045
046    /** Version id. */
047    private static final long serialVersionUID = 1L;
048
049    /** Saved scrollTop value. */
050    Integer m_scrollTop;
051
052    /**
053     * @see com.vaadin.client.ui.panel.PanelConnector#postLayout()
054     */
055    @Override
056    public void postLayout() {
057
058        super.postLayout();
059
060        if (m_scrollTop != null) {
061            final int newScrollTop = m_scrollTop.intValue();
062            Timer timer = new Timer() {
063
064                @Override
065                public void run() {
066
067                    getWidget().contentNode.setScrollTop(newScrollTop);
068                    m_scrollTop = null;
069                }
070            };
071            timer.schedule(50);
072        }
073    }
074
075    /**
076     * @see com.vaadin.client.ui.panel.PanelConnector#updateFromUIDL(com.vaadin.client.UIDL, com.vaadin.client.ApplicationConnection)
077     */
078    @SuppressWarnings("deprecation")
079    @Override
080    public void updateFromUIDL(UIDL uidl, ApplicationConnection client) {
081
082        super.updateFromUIDL(uidl, client);
083        if (isRealUpdate(uidl)) {
084            m_scrollTop = Integer.valueOf(getState().scrollTop);
085        }
086    }
087
088}