annotationtransfer.java

编辑视频文件

/*
 * File:     AnnotationTransfer.java
 * Project:  MPI Linguistic Application
 * Date:     02 May 2007
 *
 * Copyright (C) 2001-2007  Max Planck Institute for Psycholinguistics
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package mpi.eudico.client.annotator.util;

import java.awt.Toolkit;
import java.awt.datatransfer.Transferable;


/**
 * Utility class with methods to check the accessibility of the Clipboard and the
 * type of contents on the clipboard.
 *
 * @author Han Sloetjes, MPI
 */
public class AnnotationTransfer implements ClientLogger {
    /**
     * Constructor.
     */
    AnnotationTransfer() {
        super();
    }

    /**
     * Checks the contents of the clipboard.
     *
     * @return true if there is valid contents on the clipboard
     * (TransferableAnnotation or TransferableAnnotationTree),
     * false otherwise
     */
    public static boolean validContentsOnClipboard() {
        if (canAccessSystemClipboard()) {
            try {
                // get Clipboard contents.
                Transferable ta = Toolkit.getDefaultToolkit()
                                         .getSystemClipboard().getContents(null);

                if (ta != null) {
                    try {
                        ta.getTransferData(AnnotationDataFlavor.getInstance());

                        return true;
                    } catch (Exception ee) {
                        try {
                            ta.getTransferData(AnnotationTreeDataFlavor.getInstance());

                            return true;
                        } catch (Exception eee) {
                        }
                    }
                }
            } catch (Exception ex) {
            }
        }

        return false;
    }

    /**
     * Performs a check on the accessibility of the system clipboard.
     *
     * @return true if the system clipboard is accessible, false otherwise
     */
    public static boolean canAccessSystemClipboard() {
        if (System.getSecurityManager() != null) {
            try {
                System.getSecurityManager().checkSystemClipboardAccess();

                return true;
            } catch (SecurityException se) {
                LOG.warning(se.getMessage());

                //se.printStackTrace();
                return false;
            }
        }

        return true;
    }
}