org.nightlabs.base.ui.util.SelectionUtil.java Source code

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Here is the source code for org.nightlabs.base.ui.util.SelectionUtil.java

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/* *****************************************************************************
 * org.nightlabs.base.ui - NightLabs Eclipse utilities                            *
 * Copyright (C) 2004-2005 NightLabs - http://NightLabs.org                    *
 *                                                                             *
 * This library is free software; you can redistribute it and/or               *
 * modify it under the terms of the GNU Lesser General Public                  *
 * License as published by the Free Software Foundation; either                *
 * version 2.1 of the License, or (at your option) any later version.          *
 *                                                                             *
 * This library 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           *
 * Lesser General Public License for more details.                             *
 *                                                                             *
 * You should have received a copy of the GNU Lesser General Public            *
 * License along with this library; if not, write to the                       *
 *     Free Software Foundation, Inc.,                                         *
 *     51 Franklin St, Fifth Floor,                                            *
 *     Boston, MA  02110-1301  USA                                             *
 *                                                                             *
 * Or get it online :                                                          *
 *     http://www.gnu.org/copyleft/lesser.html                                 *
 *                                                                             *
 *                                                                             *
 ******************************************************************************/

package org.nightlabs.base.ui.util;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.StructuredSelection;

public class SelectionUtil {
    public SelectionUtil() {
        super();
    }

    /**
     * 
     * @param selection the ISelection to check
     * @param clazz the Class which determines which entries are allowed
     * @return a StructuredSelection which contains only Objects from the given
     * selection of the given Class
     */
    @SuppressWarnings("unchecked") //$NON-NLS-1$
    public static StructuredSelection checkSelection(ISelection selection, Class clazz) {
        if (!selection.isEmpty() && selection instanceof StructuredSelection) {
            List<Object> list = new ArrayList<Object>();
            boolean containsOther = false;
            StructuredSelection s = (StructuredSelection) selection;
            for (Iterator it = s.iterator(); it.hasNext();) {
                Object o = it.next();
                if (clazz.isAssignableFrom(o.getClass())) {
                    list.add(o);
                } else {
                    containsOther = true;
                }
            }
            if (!containsOther)
                return s;
            else
                return new StructuredSelection(list);
        }
        return StructuredSelection.EMPTY;
    }

    /**
     * 
     * @param l the list to check
     * @param clazz the Class which determines which entries are allowed
     * @return a List which contains only Objects which are assignable from
     * the given Class and were contained in the given list
     */
    @SuppressWarnings("unchecked") //$NON-NLS-1$
    public static List checkList(List l, Class clazz) {
        List<Object> list = new ArrayList<Object>();
        boolean containsOther = false;
        for (Iterator it = list.iterator(); it.hasNext();) {
            Object o = it.next();
            if (clazz.isAssignableFrom(o.getClass())) {
                list.add(o);
            } else {
                containsOther = true;
            }
        }
        if (!containsOther)
            return l;
        else
            return list;
    }

}