/*
 * File:     PreviousFrameCommand.java
 * Project:  MPI Linguistic Application
 * Date:     03 April 2006
 *
 * Copyright (C) 2001-2006  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.commands;

import mpi.eudico.client.annotator.player.ElanMediaPlayer;


/**
 * DOCUMENT ME!
 * $Id: PreviousFrameCommand.java,v 1.1 2005/08/03 14:59:51 hasloe Exp $
 * @author $Author: hasloe $
 * @version $Revision: 1.1 $
 */
public class PreviousFrameCommand implements Command {
    private String commandName;

    /**
     * Creates a new PreviousFrameCommand instance
     *
     * @param theName DOCUMENT ME!
     */
    public PreviousFrameCommand(String theName) {
        commandName = theName;
    }

    /**
     * DOCUMENT ME!
     *
     * @param receiver DOCUMENT ME!
     * @param arguments DOCUMENT ME!
     */
    public void execute(Object receiver, Object[] arguments) {
        // receiver is master ElanMediaPlayer
        if (receiver != null) {
            // replaced by nextFrame.
            // getMillisecondsPerSample returns a long so there are rounding errors for ntsc
            // further some media platforms support direct frame stepping that can handle dropped frames

            /*long msPerFrame = ((ElanMediaPlayer) receiver).getMilliSecondsPerSample();
            long frame = ((ElanMediaPlayer) receiver).getMediaTime() / msPerFrame;

            if (frame > 0) {
                ((ElanMediaPlayer) receiver).setMediaTime((frame - 1) * msPerFrame);
            }*/
            ((ElanMediaPlayer) receiver).previousFrame();
        }
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getName() {
        return commandName;
    }
}
