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/*
 * AbstractReadButton.java 0.0.4 30th December 2000
 *
 * Copyright (C) 2000 Adam Kirby
 *
 * 
 *
 * 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 jm.util;

import jm.midi.SMF;
import jm.music.data.Score;

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.*;

/**
 * A abstract button class which handles reading of MIDI and jMusic files.
 * 
 * This is designed for user interfaces.  If exceptions occur a dialog box is
 * created and displayed detailing the problem.
 * 
 * If you want the errors to be transparent to your user, or you want to
 * manage exception-handling try using the {@link jm.util.Read} class instead.
 *
 * @author Adam Kirby
 * @version 1.0, Sun Feb 25 18:43:56  2001
 */
public abstract class AbstractReadButton extends Button {
    /**
     * The owner whose control is to be suspended when an error dialog or
     * FileDialog appears.
     */
    protected Frame owner = null;

    /**
     * Checks to see whether the file specified is a valid JM or MIDI and if so
     * returns its data as a Score.  If an error is encountered a dialog box is
     * displayed describing the error, and the method returns null.
     *
     * @param directoryName String describing the directory structure of the
     *                      file to be read
     * @param fileName      String describing the full name of the file to be
     *                      read
     * @return {@link Score} describing the music data in the file,
     * or null if an error was encountered.
     */
    public Score readFile(final String directoryName, final String fileName) {
        if (directoryName == null || fileName == null) {
            return null;
        }

        Score score = null;
        String message = null;

        /** Attempt to read file */
        try {
            SMF smf = new SMF();
            score = new Score(fileName);
            InputStream is = new FileInputStream(directoryName + fileName);
            smf.read(is);
            jm.midi.MidiParser.SMFToScore(score, smf);
        } catch (IOException e1) {
            message = e1.getMessage();
            if (message == null) {
                message = "Unknown IO Exception";
            } else if (message.equals("Track Started in wrong place!!!!"
                    + "  ABORTING")) {
                message = "The MIDI file corrupted.  Track data started in the"
                        + " wrong place.";
            } else if (message.equals("This is NOT a MIDI file !!!")) {
                try {
                    FileInputStream fis = new FileInputStream(directoryName
                            + fileName);
                    ObjectInputStream ois = new ObjectInputStream(fis);
                    score = (Score) ois.readObject();
                    ois.close();
                    fis.close();
                } catch (SecurityException e2) {
                    message = "Read access not allowed to " + fileName;
                } catch (ClassNotFoundException e2) {
                    message = "The file " + fileName
                            + " is neither a jm or MIDI file";
                } catch (ClassCastException e2) {
                    message = "The file " + fileName
                            + " is neither a jm or MIDI file";
                } catch (StreamCorruptedException e2) {
                    message = "The file " + fileName
                            + " is neither a jm or MIDI file";
                } catch (IOException e2) {
                    message = e2.getMessage();
                    if (message == null) {
                        message = "Unknown Exception";
                    }
                }
            }
        }

        /** Display error if any */
        if (message != null) {
            final String finalMessage = message;
            new Dialog(owner, "Not a valid MIDI or jMusic File", true) {
                {
                    add(new Label(finalMessage));
                    addWindowListener(new WindowAdapter() {
                                          public void windowClosing(WindowEvent evt) {
                                              dispose();
                                          }
                                      }
                    );
                    pack();
                }
            }.show();
        }

        return score;
    }
}