J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1999-2003 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 | import java.util.List; |
| 29 | |
| 30 | /** |
| 31 | * <code>MidiDevice</code> is the base interface for all MIDI devices. |
| 32 | * Common devices include synthesizers, sequencers, MIDI input ports, and MIDI |
| 33 | * output ports. |
| 34 | * |
| 35 | * <p>A <code>MidiDevice</code> can be a transmitter or a receiver of |
| 36 | * MIDI events, or both. Therefore, it can provide {@link Transmitter} |
| 37 | * or {@link Receiver} instances (or both). Typically, MIDI IN ports |
| 38 | * provide transmitters, MIDI OUT ports and synthesizers provide |
| 39 | * receivers. A Sequencer typically provides transmitters for playback |
| 40 | * and receivers for recording. |
| 41 | * |
| 42 | * <p>A <code>MidiDevice</code> can be opened and closed explicitly as |
| 43 | * well as implicitly. Explicit opening is accomplished by calling |
| 44 | * {@link #open}, explicit closing is done by calling {@link |
| 45 | * #close} on the <code>MidiDevice</code> instance. |
| 46 | * If an application opens a <code>MidiDevice</code> |
| 47 | * explicitly, it has to close it explicitly to free system resources |
| 48 | * and enable the application to exit cleanly. Implicit opening is |
| 49 | * done by calling {@link javax.sound.midi.MidiSystem#getReceiver |
| 50 | * MidiSystem.getReceiver} and {@link |
| 51 | * javax.sound.midi.MidiSystem#getTransmitter |
| 52 | * MidiSystem.getTransmitter}. The <code>MidiDevice</code> used by |
| 53 | * <code>MidiSystem.getReceiver</code> and |
| 54 | * <code>MidiSystem.getTransmitter</code> is implementation-dependant |
| 55 | * unless the properties <code>javax.sound.midi.Receiver</code> |
| 56 | * and <code>javax.sound.midi.Transmitter</code> are used (see the |
| 57 | * description of properties to select default providers in |
| 58 | * {@link javax.sound.midi.MidiSystem}). A <code>MidiDevice</code> |
| 59 | * that was opened implicitly, is closed implicitly by closing the |
| 60 | * <code>Receiver</code> or <code>Transmitter</code> that resulted in |
| 61 | * opening it. If more than one implicitly opening |
| 62 | * <code>Receiver</code> or <code>Transmitter</code> were obtained by |
| 63 | * the application, the decive is closed after the last |
| 64 | * <code>Receiver</code> or <code>Transmitter</code> has been |
| 65 | * closed. On the other hand, calling <code>getReceiver</code> or |
| 66 | * <code>getTransmitter</code> on the device instance directly does |
| 67 | * not open the device implicitly. Closing these |
| 68 | * <code>Transmitter</code>s and <code>Receiver</code>s does not close |
| 69 | * the device implicitly. To use a device with <code>Receiver</code>s |
| 70 | * or <code>Transmitter</code>s obtained this way, the device has to |
| 71 | * be opened and closed explicitly. |
| 72 | * |
| 73 | * <p>If implicit and explicit opening and closing are mixed on the |
| 74 | * same <code>MidiDevice</code> instance, the following rules apply: |
| 75 | * |
| 76 | * <ul> |
| 77 | * <li>After an explicit open (either before or after implicit |
| 78 | * opens), the device will not be closed by implicit closing. The only |
| 79 | * way to close an explicitly opened device is an explicit close.</li> |
| 80 | * |
| 81 | * <li>An explicit close always closes the device, even if it also has |
| 82 | * been opened implicitly. A subsequent implicit close has no further |
| 83 | * effect.</li> |
| 84 | * </ul> |
| 85 | * |
| 86 | * To detect if a MidiDevice represents a hardware MIDI port, the |
| 87 | * following programming technique can be used: |
| 88 | * |
| 89 | * <pre> |
| 90 | * MidiDevice device = ...; |
| 91 | * if ( ! (device instanceof Sequencer) && ! (device instanceof Synthesizer)) { |
| 92 | * // we're now sure that device represents a MIDI port |
| 93 | * // ... |
| 94 | * } |
| 95 | * </pre> |
| 96 | * |
| 97 | * <p> |
| 98 | * A <code>MidiDevice</code> includes a <code>{@link MidiDevice.Info}</code> object |
| 99 | * to provide manufacturer information and so on. |
| 100 | * |
| 101 | * @see Synthesizer |
| 102 | * @see Sequencer |
| 103 | * @see Receiver |
| 104 | * @see Transmitter |
| 105 | * |
| 106 | * @author Kara Kytle |
| 107 | * @author Florian Bomers |
| 108 | */ |
| 109 | |
| 110 | public interface MidiDevice { |
| 111 | |
| 112 | |
| 113 | /** |
| 114 | * Obtains information about the device, including its Java class and |
| 115 | * <code>Strings</code> containing its name, vendor, and description. |
| 116 | * |
| 117 | * @return device info |
| 118 | */ |
| 119 | public Info getDeviceInfo(); |
| 120 | |
| 121 | |
| 122 | /** |
| 123 | * Opens the device, indicating that it should now acquire any |
| 124 | * system resources it requires and become operational. |
| 125 | * |
| 126 | * <p>An application opening a device explicitly with this call |
| 127 | * has to close the device by calling {@link #close}. This is |
| 128 | * necessary to release system resources and allow applications to |
| 129 | * exit cleanly. |
| 130 | * |
| 131 | * <p> |
| 132 | * Note that some devices, once closed, cannot be reopened. Attempts |
| 133 | * to reopen such a device will always result in a MidiUnavailableException. |
| 134 | * |
| 135 | * @throws MidiUnavailableException thrown if the device cannot be |
| 136 | * opened due to resource restrictions. |
| 137 | * @throws SecurityException thrown if the device cannot be |
| 138 | * opened due to security restrictions. |
| 139 | * |
| 140 | * @see #close |
| 141 | * @see #isOpen |
| 142 | */ |
| 143 | public void open() throws MidiUnavailableException; |
| 144 | |
| 145 | |
| 146 | /** |
| 147 | * Closes the device, indicating that the device should now release |
| 148 | * any system resources it is using. |
| 149 | * |
| 150 | * <p>All <code>Receiver</code> and <code>Transmitter</code> instances |
| 151 | * open from this device are closed. This includes instances retrieved |
| 152 | * via <code>MidiSystem</code>. |
| 153 | * |
| 154 | * @see #open |
| 155 | * @see #isOpen |
| 156 | */ |
| 157 | public void close(); |
| 158 | |
| 159 | |
| 160 | /** |
| 161 | * Reports whether the device is open. |
| 162 | * |
| 163 | * @return <code>true</code> if the device is open, otherwise |
| 164 | * <code>false</code> |
| 165 | * @see #open |
| 166 | * @see #close |
| 167 | */ |
| 168 | public boolean isOpen(); |
| 169 | |
| 170 | |
| 171 | /** |
| 172 | * Obtains the current time-stamp of the device, in microseconds. |
| 173 | * If a device supports time-stamps, it should start counting at |
| 174 | * 0 when the device is opened and continue incrementing its |
| 175 | * time-stamp in microseconds until the device is closed. |
| 176 | * If it does not support time-stamps, it should always return |
| 177 | * -1. |
| 178 | * @return the current time-stamp of the device in microseconds, |
| 179 | * or -1 if time-stamping is not supported by the device. |
| 180 | */ |
| 181 | public long getMicrosecondPosition(); |
| 182 | |
| 183 | |
| 184 | /** |
| 185 | * Obtains the maximum number of MIDI IN connections available on this |
| 186 | * MIDI device for receiving MIDI data. |
| 187 | * @return maximum number of MIDI IN connections, |
| 188 | * or -1 if an unlimited number of connections is available. |
| 189 | */ |
| 190 | public int getMaxReceivers(); |
| 191 | |
| 192 | |
| 193 | /** |
| 194 | * Obtains the maximum number of MIDI OUT connections available on this |
| 195 | * MIDI device for transmitting MIDI data. |
| 196 | * @return maximum number of MIDI OUT connections, |
| 197 | * or -1 if an unlimited number of connections is available. |
| 198 | */ |
| 199 | public int getMaxTransmitters(); |
| 200 | |
| 201 | |
| 202 | /** |
| 203 | * Obtains a MIDI IN receiver through which the MIDI device may receive |
| 204 | * MIDI data. The returned receiver must be closed when the application |
| 205 | * has finished using it. |
| 206 | * |
| 207 | * <p>Obtaining a <code>Receiver</code> with this method does not |
| 208 | * open the device. To be able to use the device, it has to be |
| 209 | * opened explicitly by calling {@link #open}. Also, closing the |
| 210 | * <code>Receiver</code> does not close the device. It has to be |
| 211 | * closed explicitly by calling {@link #close}. |
| 212 | * |
| 213 | * @return a receiver for the device. |
| 214 | * @throws MidiUnavailableException thrown if a receiver is not available |
| 215 | * due to resource restrictions |
| 216 | * @see Receiver#close() |
| 217 | */ |
| 218 | public Receiver getReceiver() throws MidiUnavailableException; |
| 219 | |
| 220 | |
| 221 | /** |
| 222 | * Returns all currently active, non-closed receivers |
| 223 | * connected with this MidiDevice. |
| 224 | * A receiver can be removed |
| 225 | * from the device by closing it. |
| 226 | * @return an unmodifiable list of the open receivers |
| 227 | * @since 1.5 |
| 228 | */ |
| 229 | List<Receiver> getReceivers(); |
| 230 | |
| 231 | |
| 232 | /** |
| 233 | * Obtains a MIDI OUT connection from which the MIDI device will transmit |
| 234 | * MIDI data The returned transmitter must be closed when the application |
| 235 | * has finished using it. |
| 236 | * |
| 237 | * <p>Obtaining a <code>Transmitter</code> with this method does not |
| 238 | * open the device. To be able to use the device, it has to be |
| 239 | * opened explicitly by calling {@link #open}. Also, closing the |
| 240 | * <code>Transmitter</code> does not close the device. It has to be |
| 241 | * closed explicitly by calling {@link #close}. |
| 242 | * |
| 243 | * @return a MIDI OUT transmitter for the device. |
| 244 | * @throws MidiUnavailableException thrown if a transmitter is not available |
| 245 | * due to resource restrictions |
| 246 | * @see Transmitter#close() |
| 247 | */ |
| 248 | public Transmitter getTransmitter() throws MidiUnavailableException; |
| 249 | |
| 250 | |
| 251 | /** |
| 252 | * Returns all currently active, non-closed transmitters |
| 253 | * connected with this MidiDevice. |
| 254 | * A transmitter can be removed |
| 255 | * from the device by closing it. |
| 256 | * @return an unmodifiable list of the open transmitters |
| 257 | * @since 1.5 |
| 258 | */ |
| 259 | List<Transmitter> getTransmitters(); |
| 260 | |
| 261 | |
| 262 | |
| 263 | /** |
| 264 | * A <code>MidiDevice.Info</code> object contains assorted |
| 265 | * data about a <code>{@link MidiDevice}</code>, including its |
| 266 | * name, the company who created it, and descriptive text. |
| 267 | * |
| 268 | * @see MidiDevice#getDeviceInfo |
| 269 | */ |
| 270 | public static class Info { |
| 271 | |
| 272 | /** |
| 273 | * The device's name. |
| 274 | */ |
| 275 | private String name; |
| 276 | |
| 277 | /** |
| 278 | * The name of the company who provides the device. |
| 279 | */ |
| 280 | private String vendor; |
| 281 | |
| 282 | /** |
| 283 | * A description of the device. |
| 284 | */ |
| 285 | private String description; |
| 286 | |
| 287 | /** |
| 288 | * Device version. |
| 289 | */ |
| 290 | private String version; |
| 291 | |
| 292 | |
| 293 | /** |
| 294 | * Constructs a device info object. |
| 295 | * |
| 296 | * @param name the name of the device |
| 297 | * @param vendor the name of the company who provides the device |
| 298 | * @param description a description of the device |
| 299 | * @param version version information for the device |
| 300 | */ |
| 301 | protected Info(String name, String vendor, String description, String version) { |
| 302 | |
| 303 | this.name = name; |
| 304 | this.vendor = vendor; |
| 305 | this.description = description; |
| 306 | this.version = version; |
| 307 | } |
| 308 | |
| 309 | |
| 310 | /** |
| 311 | * Reports whether two objects are equal. |
| 312 | * Returns <code>true</code> if the objects are identical. |
| 313 | * @param obj the reference object with which to compare this |
| 314 | * object |
| 315 | * @return <code>true</code> if this object is the same as the |
| 316 | * <code>obj</code> argument; <code>false</code> otherwise |
| 317 | */ |
| 318 | public final boolean equals(Object obj) { |
| 319 | return super.equals(obj); |
| 320 | } |
| 321 | |
| 322 | |
| 323 | /** |
| 324 | * Finalizes the hashcode method. |
| 325 | */ |
| 326 | public final int hashCode() { |
| 327 | return super.hashCode(); |
| 328 | } |
| 329 | |
| 330 | |
| 331 | /** |
| 332 | * Obtains the name of the device. |
| 333 | * |
| 334 | * @return a string containing the device's name |
| 335 | */ |
| 336 | public final String getName() { |
| 337 | return name; |
| 338 | } |
| 339 | |
| 340 | |
| 341 | /** |
| 342 | * Obtains the name of the company who supplies the device. |
| 343 | * @return device the vendor's name |
| 344 | */ |
| 345 | public final String getVendor() { |
| 346 | return vendor; |
| 347 | } |
| 348 | |
| 349 | |
| 350 | /** |
| 351 | * Obtains the description of the device. |
| 352 | * @return a description of the device |
| 353 | */ |
| 354 | public final String getDescription() { |
| 355 | return description; |
| 356 | } |
| 357 | |
| 358 | |
| 359 | /** |
| 360 | * Obtains the version of the device. |
| 361 | * @return textual version information for the device. |
| 362 | */ |
| 363 | public final String getVersion() { |
| 364 | return version; |
| 365 | } |
| 366 | |
| 367 | |
| 368 | /** |
| 369 | * Provides a string representation of the device information. |
| 370 | |
| 371 | * @return a description of the info object |
| 372 | */ |
| 373 | public final String toString() { |
| 374 | return name; |
| 375 | } |
| 376 | } // class Info |
| 377 | |
| 378 | |
| 379 | } |