J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1998-2002 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.sound.midi; |
| 27 | |
| 28 | /** |
| 29 | * A <code>SysexMessage</code> object represents a MIDI system exclusive message. |
| 30 | * <p> |
| 31 | * When a system exclusive message is read from a MIDI file, it always has |
| 32 | * a defined length. Data from a system exclusive message from a MIDI file |
| 33 | * should be stored in the data array of a <code>SysexMessage</code> as |
| 34 | * follows: the system exclusive message status byte (0xF0 or 0xF7), all |
| 35 | * message data bytes, and finally the end-of-exclusive flag (0xF7). |
| 36 | * The length reported by the <code>SysexMessage</code> object is therefore |
| 37 | * the length of the system exclusive data plus two: one byte for the status |
| 38 | * byte and one for the end-of-exclusive flag. |
| 39 | * <p> |
| 40 | * As dictated by the Standard MIDI Files specification, two status byte values are legal |
| 41 | * for a <code>SysexMessage</code> read from a MIDI file: |
| 42 | * <ul> |
| 43 | * <li>0xF0: System Exclusive message (same as in MIDI wire protocol)</li> |
| 44 | * <li>0xF7: Special System Exclusive message</li> |
| 45 | * </ul> |
| 46 | * <p> |
| 47 | * When Java Sound is used to handle system exclusive data that is being received |
| 48 | * using MIDI wire protocol, it should place the data in one or more |
| 49 | * <code>SysexMessages</code>. In this case, the length of the system exclusive data |
| 50 | * is not known in advance; the end of the system exclusive data is marked by an |
| 51 | * end-of-exclusive flag (0xF7) in the MIDI wire byte stream. |
| 52 | * <ul> |
| 53 | * <li>0xF0: System Exclusive message (same as in MIDI wire protocol)</li> |
| 54 | * <li>0xF7: End of Exclusive (EOX)</li> |
| 55 | * </ul> |
| 56 | * The first <code>SysexMessage</code> object containing data for a particular system |
| 57 | * exclusive message should have the status value 0xF0. If this message contains all |
| 58 | * the system exclusive data |
| 59 | * for the message, it should end with the status byte 0xF7 (EOX). |
| 60 | * Otherwise, additional system exclusive data should be sent in one or more |
| 61 | * <code>SysexMessages</code> with a status value of 0xF7. The <code>SysexMessage</code> |
| 62 | * containing the last of the data for the system exclusive message should end with the |
| 63 | * value 0xF7 (EOX) to mark the end of the system exclusive message. |
| 64 | * <p> |
| 65 | * If system exclusive data from <code>SysexMessages</code> objects is being transmitted |
| 66 | * using MIDI wire protocol, only the initial 0xF0 status byte, the system exclusive |
| 67 | * data itself, and the final 0xF7 (EOX) byte should be propagated; any 0xF7 status |
| 68 | * bytes used to indicate that a <code>SysexMessage</code> contains continuing system |
| 69 | * exclusive data should not be propagated via MIDI wire protocol. |
| 70 | * |
| 71 | * @author David Rivas |
| 72 | * @author Kara Kytle |
| 73 | * @author Florian Bomers |
| 74 | */ |
| 75 | public class SysexMessage extends MidiMessage { |
| 76 | |
| 77 | |
| 78 | // Status byte defines |
| 79 | |
| 80 | |
| 81 | /** |
| 82 | * Status byte for System Exclusive message (0xF0, or 240). |
| 83 | * @see MidiMessage#getStatus |
| 84 | */ |
| 85 | public static final int SYSTEM_EXCLUSIVE = 0xF0; // 240 |
| 86 | |
| 87 | |
| 88 | /** |
| 89 | * Status byte for Special System Exclusive message (0xF7, or 247), which is used |
| 90 | * in MIDI files. It has the same value as END_OF_EXCLUSIVE, which |
| 91 | * is used in the real-time "MIDI wire" protocol. |
| 92 | * @see MidiMessage#getStatus |
| 93 | */ |
| 94 | public static final int SPECIAL_SYSTEM_EXCLUSIVE = 0xF7; // 247 |
| 95 | |
| 96 | |
| 97 | // Instance variables |
| 98 | |
| 99 | |
| 100 | /* |
| 101 | * The data bytes for this system exclusive message. These are |
| 102 | * initialized to <code>null</code> and are set explicitly |
| 103 | * by {@link #setMessage(int, byte[], int, long) setMessage}. |
| 104 | */ |
| 105 | //protected byte[] data = null; |
| 106 | |
| 107 | |
| 108 | /** |
| 109 | * Constructs a new <code>SysexMessage</code>. The |
| 110 | * contents of the new message are guaranteed to specify |
| 111 | * a valid MIDI message. Subsequently, you may set the |
| 112 | * contents of the message using one of the <code>setMessage</code> |
| 113 | * methods. |
| 114 | * @see #setMessage |
| 115 | */ |
| 116 | public SysexMessage() { |
| 117 | this(new byte[2]); |
| 118 | // Default sysex message data: SOX followed by EOX |
| 119 | data[0] = (byte) (SYSTEM_EXCLUSIVE & 0xFF); |
| 120 | data[1] = (byte) (ShortMessage.END_OF_EXCLUSIVE & 0xFF); |
| 121 | } |
| 122 | |
| 123 | |
| 124 | /** |
| 125 | * Constructs a new <code>SysexMessage</code>. |
| 126 | * @param data an array of bytes containing the complete message. |
| 127 | * The message data may be changed using the <code>setMessage</code> |
| 128 | * method. |
| 129 | * @see #setMessage |
| 130 | */ |
| 131 | protected SysexMessage(byte[] data) { |
| 132 | super(data); |
| 133 | } |
| 134 | |
| 135 | |
| 136 | /** |
| 137 | * Sets the data for the system exclusive message. The |
| 138 | * first byte of the data array must be a valid system |
| 139 | * exclusive status byte (0xF0 or 0xF7). |
| 140 | * @param data the system exclusive message data |
| 141 | * @param length the length of the valid message data in |
| 142 | * the array, including the status byte. |
| 143 | */ |
| 144 | public void setMessage(byte[] data, int length) throws InvalidMidiDataException { |
| 145 | int status = (data[0] & 0xFF); |
| 146 | if ((status != 0xF0) && (status != 0xF7)) { |
| 147 | throw new InvalidMidiDataException("Invalid status byte for sysex message: 0x" + Integer.toHexString(status)); |
| 148 | } |
| 149 | super.setMessage(data, length); |
| 150 | } |
| 151 | |
| 152 | |
| 153 | /** |
| 154 | * Sets the data for the system exclusive message. |
| 155 | * @param status the status byte for the message (0xF0 or 0xF7) |
| 156 | * @param data the system exclusive message data |
| 157 | * @param length the length of the valid message data in |
| 158 | * the array |
| 159 | */ |
| 160 | public void setMessage(int status, byte[] data, int length) throws InvalidMidiDataException { |
| 161 | if ( (status != 0xF0) && (status != 0xF7) ) { |
| 162 | throw new InvalidMidiDataException("Invalid status byte for sysex message: 0x" + Integer.toHexString(status)); |
| 163 | } |
| 164 | if (length < 0 || length > data.length) { |
| 165 | throw new IndexOutOfBoundsException("length out of bounds: "+length); |
| 166 | } |
| 167 | this.length = length + 1; |
| 168 | |
| 169 | if (this.data==null || this.data.length < this.length) { |
| 170 | this.data = new byte[this.length]; |
| 171 | } |
| 172 | |
| 173 | this.data[0] = (byte) (status & 0xFF); |
| 174 | if (length > 0) { |
| 175 | System.arraycopy(data, 0, this.data, 1, length); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | |
| 180 | /** |
| 181 | * Obtains a copy of the data for the system exclusive message. |
| 182 | * The returned array of bytes does not include the status byte. |
| 183 | * @return array containing the system exclusive message data. |
| 184 | */ |
| 185 | public byte[] getData() { |
| 186 | byte[] returnedArray = new byte[length - 1]; |
| 187 | System.arraycopy(data, 1, returnedArray, 0, (length - 1)); |
| 188 | return returnedArray; |
| 189 | } |
| 190 | |
| 191 | |
| 192 | /** |
| 193 | * Creates a new object of the same class and with the same contents |
| 194 | * as this object. |
| 195 | * @return a clone of this instance |
| 196 | */ |
| 197 | public Object clone() { |
| 198 | byte[] newData = new byte[length]; |
| 199 | System.arraycopy(data, 0, newData, 0, newData.length); |
| 200 | SysexMessage event = new SysexMessage(newData); |
| 201 | return event; |
| 202 | } |
| 203 | } |