001 /* ShortMessage.java -- A MIDI message no longer than 3 bytes 002 Copyright (C) 2005 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package javax.sound.midi; 040 041 /** 042 * A short MIDI message that is no longer than 3 bytes long. 043 * 044 * @author Anthony Green (green@redhat.com) 045 * @since 1.3 046 * 047 */ 048 public class ShortMessage extends MidiMessage 049 { 050 /** 051 * Status byte for Time Code message. 052 */ 053 public static final int MIDI_TIME_CODE = 0xF1; 054 055 /** 056 * Status byte for Song Position Pointer message. 057 */ 058 public static final int SONG_POSITION_POINTER = 0xF2; 059 060 /** 061 * Status byte for Song Select message. 062 */ 063 public static final int SONG_SELECT = 0xF3; 064 065 /** 066 * Status byte for Tune Request message. 067 */ 068 public static final int TUNE_REQUEST = 0xF6; 069 070 /** 071 * Status byte for End Of Exclusive message. 072 */ 073 public static final int END_OF_EXCLUSIVE = 0xF7; 074 075 /** 076 * Status byte for Timing Clock message. 077 */ 078 public static final int TIMING_CLOCK = 0xF8; 079 080 /** 081 * Status byte for Start message. 082 */ 083 public static final int START = 0xFA; 084 085 /** 086 * Status byte for Continue message. 087 */ 088 public static final int CONTINUE = 0xFB; 089 090 /** 091 * Status byte for Stop message. 092 */ 093 public static final int STOP = 0xFC; 094 095 /** 096 * Status byte for Active Sensing message. 097 */ 098 public static final int ACTIVE_SENSING = 0xFE; 099 100 /** 101 * Status byte for System Reset message. 102 */ 103 public static final int SYSTEM_RESET = 0xFF; 104 105 /** 106 * Status nibble for Note Off message. 107 */ 108 public static final int NOTE_OFF = 0x80; 109 110 /** 111 * Status nibble for Note On message. 112 */ 113 public static final int NOTE_ON = 0x90; 114 115 /** 116 * Status nibble for Poly Pressure message. 117 */ 118 public static final int POLY_PRESSURE = 0xA0; 119 120 /** 121 * Status nibble for Control Change message. 122 */ 123 public static final int CONTROL_CHANGE = 0xB0; 124 125 /** 126 * Status nibble for Program Change message. 127 */ 128 public static final int PROGRAM_CHANGE = 0xC0; 129 130 /** 131 * Statue nibble for Channel Pressure message. 132 */ 133 public static final int CHANNEL_PRESSURE = 0xD0; 134 135 /** 136 * Status nibble for Pitch Bend message. 137 */ 138 public static final int PITCH_BEND = 0xE0; 139 140 // Create and initialize a default, arbitrary message. 141 private static byte[] defaultMessage; 142 static 143 { 144 defaultMessage = new byte[1]; 145 defaultMessage[0] = (byte) STOP; 146 } 147 148 /** 149 * Create a short MIDI message. 150 * 151 * The spec requires that this represent a valid MIDI message, but doesn't 152 * specify what it should be. We've chosen the STOP message for our 153 * implementation. 154 */ 155 public ShortMessage() 156 { 157 this(defaultMessage); 158 } 159 160 /** 161 * Create a short MIDI message. 162 * 163 * The data argument should be a valid MIDI message. Unfortunately the spec 164 * does not allow us to throw an InvalidMidiDataException if data is invalid. 165 * 166 * @param data the message data 167 */ 168 protected ShortMessage(byte[] data) 169 { 170 super(data); 171 } 172 173 /** 174 * Set the MIDI message. 175 * 176 * @param status the status byte for this message 177 * @param data1 the first data byte for this message 178 * @param data2 the second data byte for this message 179 * @throws InvalidMidiDataException if status is bad, or data is out of range 180 */ 181 public void setMessage(int status, int data1, int data2) 182 throws InvalidMidiDataException 183 { 184 length = getDataLength(status); 185 length++; 186 if (data == null || data.length < length) 187 data = new byte[length]; 188 data[0] = (byte) status; 189 if (length > 1) 190 { 191 if (data1 < 0 || data1 > 127) 192 throw new InvalidMidiDataException("data1 (" + data1 193 + ") must be between 0 and 127."); 194 data[1] = (byte) data1; 195 if (length > 2) 196 { 197 if (data2 < 0 || data2 > 127) 198 throw new InvalidMidiDataException("data2 (" + data2 199 + ") must be between 0 and 127."); 200 data[2] = (byte) data2; 201 } 202 } 203 } 204 205 public void setMessage(int command, int channel, int data1, int data2) 206 throws InvalidMidiDataException 207 { 208 // TODO: This could probably stand some error checking. 209 // It currently assumes command and channel are valid values. 210 setMessage(command + channel, data1, data2); 211 } 212 213 /** 214 * Set the MIDI message to one that requires no data bytes. 215 * 216 * @param status the status byte for this message 217 * @throws InvalidMidiDataException if status is bad, or requires data 218 */ 219 public void setMessage(int status) throws InvalidMidiDataException 220 { 221 int length = getDataLength(status); 222 if (length != 0) 223 throw new InvalidMidiDataException("Status byte 0x" 224 + Integer.toHexString(status) 225 + " requires " 226 + length + " bytes of data."); 227 setMessage(status, 0, 0); 228 } 229 230 231 /** 232 * Return the number of data bytes needed for a given MIDI status byte. 233 * 234 * @param status the status byte for a short MIDI message 235 * @return the number of data bytes needed for this status byte 236 * @throws InvalidMidiDataException if status is an invalid status byte 237 */ 238 protected final int getDataLength(int status) throws InvalidMidiDataException 239 { 240 int originalStatus = status; 241 242 if ((status & 0xF0) != 0xF0) 243 status &= 0xF0; 244 245 switch (status) 246 { 247 case NOTE_OFF: 248 case NOTE_ON: 249 case POLY_PRESSURE: 250 case CONTROL_CHANGE: 251 case PITCH_BEND: 252 case SONG_POSITION_POINTER: 253 return 2; 254 255 case PROGRAM_CHANGE: 256 case CHANNEL_PRESSURE: 257 case SONG_SELECT: 258 case 0xF5: // FIXME: unofficial bus select. Not in spec?? 259 return 1; 260 261 case TUNE_REQUEST: 262 case END_OF_EXCLUSIVE: 263 case TIMING_CLOCK: 264 case START: 265 case CONTINUE: 266 case STOP: 267 case ACTIVE_SENSING: 268 case SYSTEM_RESET: 269 return 0; 270 271 default: 272 throw new InvalidMidiDataException("Invalid status: 0x" 273 + Integer.toHexString(originalStatus)); 274 } 275 } 276 277 /** 278 * Get the channel information from this MIDI message, assuming it is a 279 * MIDI channel message. 280 * 281 * @return the MIDI channel for this message 282 */ 283 public int getChannel() 284 { 285 return data[0] & 0x0F; 286 } 287 288 /** 289 * Get the command nibble from this MIDI message, assuming it is a MIDI 290 * channel message. 291 * 292 * @return the MIDI command for this message 293 */ 294 public int getCommand() 295 { 296 return data[0] & 0xF0; 297 } 298 299 /** 300 * Get the first data byte from this message, assuming it exists, and 301 * zero otherwise. 302 * 303 * @return the first data byte or zero if none exists. 304 */ 305 public int getData1() 306 { 307 if (length > 1) 308 return data[1]; 309 else 310 return 0; 311 } 312 313 /** 314 * Get the second data byte from this message, assuming it exists, and 315 * zero otherwise. 316 * 317 * @return the second date byte or zero if none exists. 318 */ 319 public int getData2() 320 { 321 if (length > 2) 322 return data[2]; 323 else 324 return 0; 325 } 326 327 /* Create a deep-copy clone of this object. 328 * @see java.lang.Object#clone() 329 */ 330 public Object clone() 331 { 332 byte message[] = new byte[length]; 333 System.arraycopy(data, 0, message, 0, length); 334 return new ShortMessage(message); 335 } 336 }