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.gwt.client.ui.tree;
029
030import com.google.gwt.event.logical.shared.OpenEvent;
031
032/**
033 * Two levels deep lazy list tree open handler abstract implementation.<p>
034 *
035 * @param <I> the specific lazy tree item implementation
036 *
037 * @since 8.0.0
038 *
039 * @see org.opencms.gwt.client.ui.tree.CmsLazyTree
040 * @see org.opencms.gwt.client.ui.tree.CmsLazyTreeItem
041 * @see org.opencms.gwt.client.ui.tree.I_CmsLazyOpenHandler
042 */
043public abstract class A_CmsDeepLazyOpenHandler<I extends CmsLazyTreeItem> extends A_CmsLazyOpenHandler<I> {
044
045    /**
046     * @see org.opencms.gwt.client.ui.tree.I_CmsLazyOpenHandler#onOpen(com.google.gwt.event.logical.shared.OpenEvent)
047     */
048    @Override
049    @SuppressWarnings("unchecked")
050    public void onOpen(OpenEvent<I> event) {
051
052        I target = event.getTarget();
053        if (target.getLoadState() == CmsLazyTreeItem.LoadState.UNLOADED) {
054            // in case the first level is not yet loaded
055            super.onOpen(event);
056        } else if (target.getChildCount() > 0) {
057            // load second level
058            int c = target.getChildCount();
059            for (int i = 0; i < c; i++) {
060                I child = (I)target.getChild(i);
061                if (child.getLoadState() != CmsLazyTreeItem.LoadState.UNLOADED) {
062                    continue;
063                }
064                child.onStartLoading();
065                child.setOpen(false);
066                load(child, null);
067            }
068        }
069    }
070}