rev 57600 : 8236980: toString() cleanup in JavaSound
Reviewed-by: XXX

   1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
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  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).
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  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
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  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.sound.midi;
  27 
  28 import java.util.List;
  29 
  30 /**
  31  * {@code MidiDevice} is the base interface for all MIDI devices. Common devices
  32  * include synthesizers, sequencers, MIDI input ports, and MIDI output ports.
  33  * <p>
  34  * A {@code MidiDevice} can be a transmitter or a receiver of MIDI events, or
  35  * both. Therefore, it can provide {@link Transmitter} or {@link Receiver}
  36  * instances (or both). Typically, MIDI IN ports provide transmitters, MIDI OUT
  37  * ports and synthesizers provide receivers. A Sequencer typically provides
  38  * transmitters for playback and receivers for recording.
  39  * <p>
  40  * A {@code MidiDevice} can be opened and closed explicitly as well as
  41  * implicitly. Explicit opening is accomplished by calling {@link #open},
  42  * explicit closing is done by calling {@link #close} on the {@code MidiDevice}
  43  * instance. If an application opens a {@code MidiDevice} explicitly, it has to
  44  * close it explicitly to free system resources and enable the application to
  45  * exit cleanly. Implicit opening is done by calling
  46  * {@link MidiSystem#getReceiver} and {@link MidiSystem#getTransmitter}. The
  47  * {@code MidiDevice} used by {@code MidiSystem.getReceiver} and
  48  * {@code MidiSystem.getTransmitter} is implementation-dependent unless the
  49  * properties {@code javax.sound.midi.Receiver} and
  50  * {@code javax.sound.midi.Transmitter} are used (see the description of
  51  * properties to select default providers in {@link MidiSystem}). A
  52  * {@code MidiDevice} that was opened implicitly, is closed implicitly by
  53  * closing the {@code Receiver} or {@code Transmitter} that resulted in opening
  54  * it. If more than one implicitly opening {@code Receiver} or
  55  * {@code Transmitter} were obtained by the application, the device is closed
  56  * after the last {@code Receiver} or {@code Transmitter} has been closed. On
  57  * the other hand, calling {@code getReceiver} or {@code getTransmitter} on the
  58  * device instance directly does not open the device implicitly. Closing these
  59  * {@code Transmitter}s and {@code Receiver}s does not close the device
  60  * implicitly. To use a device with {@code Receiver}s or {@code Transmitter}s
  61  * obtained this way, the device has to be opened and closed explicitly.
  62  * <p>
  63  * If implicit and explicit opening and closing are mixed on the same
  64  * {@code MidiDevice} instance, the following rules apply:
  65  *
  66  * <ul>
  67  *   <li>After an explicit open (either before or after implicit opens), the
  68  *   device will not be closed by implicit closing. The only way to close an
  69  *   explicitly opened device is an explicit close.
  70  *   <li>An explicit close always closes the device, even if it also has been
  71  *   opened implicitly. A subsequent implicit close has no further effect.
  72  * </ul>
  73  *
  74  * To detect if a MidiDevice represents a hardware MIDI port, the following
  75  * programming technique can be used:
  76  *
  77  * <pre>{@code
  78  * MidiDevice device = ...;
  79  * if (!(device instanceof Sequencer) && !(device instanceof Synthesizer)) {
  80  *   // we're now sure that device represents a MIDI port
  81  *   // ...
  82  * }
  83  * }</pre>
  84  *
  85  * <p>
  86  * A {@code MidiDevice} includes a {@link Info} object to provide manufacturer
  87  * information and so on.
  88  *
  89  * @author Kara Kytle
  90  * @author Florian Bomers
  91  * @see Synthesizer
  92  * @see Sequencer
  93  * @see Receiver
  94  * @see Transmitter
  95  */
  96 public interface MidiDevice extends AutoCloseable {
  97 
  98     /**
  99      * Obtains information about the device, including its Java class and
 100      * {@code Strings} containing its name, vendor, and description.
 101      *
 102      * @return device info
 103      */
 104     Info getDeviceInfo();
 105 
 106     /**
 107      * Opens the device, indicating that it should now acquire any system
 108      * resources it requires and become operational.
 109      * <p>
 110      * An application opening a device explicitly with this call has to close
 111      * the device by calling {@link #close}. This is necessary to release system
 112      * resources and allow applications to exit cleanly.
 113      * <p>
 114      * Note that some devices, once closed, cannot be reopened. Attempts to
 115      * reopen such a device will always result in a
 116      * {@code MidiUnavailableException}.
 117      *
 118      * @throws MidiUnavailableException thrown if the device cannot be opened
 119      *         due to resource restrictions
 120      * @throws SecurityException thrown if the device cannot be opened due to
 121      *         security restrictions
 122      * @see #close
 123      * @see #isOpen
 124      */
 125     void open() throws MidiUnavailableException;
 126 
 127     /**
 128      * Closes the device, indicating that the device should now release any
 129      * system resources it is using.
 130      * <p>
 131      * All {@code Receiver} and {@code Transmitter} instances open from this
 132      * device are closed. This includes instances retrieved via
 133      * {@code MidiSystem}.
 134      *
 135      * @see #open
 136      * @see #isOpen
 137      */
 138     @Override
 139     void close();
 140 
 141     /**
 142      * Reports whether the device is open.
 143      *
 144      * @return {@code true} if the device is open, otherwise {@code false}
 145      * @see #open
 146      * @see #close
 147      */
 148     boolean isOpen();
 149 
 150     /**
 151      * Obtains the current time-stamp of the device, in microseconds. If a
 152      * device supports time-stamps, it should start counting at 0 when the
 153      * device is opened and continue incrementing its time-stamp in microseconds
 154      * until the device is closed. If it does not support time-stamps, it should
 155      * always return -1.
 156      *
 157      * @return the current time-stamp of the device in microseconds, or -1 if
 158      *         time-stamping is not supported by the device
 159      */
 160     long getMicrosecondPosition();
 161 
 162     /**
 163      * Obtains the maximum number of MIDI IN connections available on this MIDI
 164      * device for receiving MIDI data.
 165      *
 166      * @return maximum number of MIDI IN connections, or -1 if an unlimited
 167      *         number of connections is available
 168      */
 169     int getMaxReceivers();
 170 
 171     /**
 172      * Obtains the maximum number of MIDI OUT connections available on this MIDI
 173      * device for transmitting MIDI data.
 174      *
 175      * @return maximum number of MIDI OUT connections, or -1 if an unlimited
 176      *         number of connections is available
 177      */
 178     int getMaxTransmitters();
 179 
 180     /**
 181      * Obtains a MIDI IN receiver through which the MIDI device may receive MIDI
 182      * data. The returned receiver must be closed when the application has
 183      * finished using it.
 184      * <p>
 185      * Usually the returned receiver implements the {@code MidiDeviceReceiver}
 186      * interface.
 187      * <p>
 188      * Obtaining a {@code Receiver} with this method does not open the device.
 189      * To be able to use the device, it has to be opened explicitly by calling
 190      * {@link #open}. Also, closing the {@code Receiver} does not close the
 191      * device. It has to be closed explicitly by calling {@link #close}.
 192      *
 193      * @return a receiver for the device
 194      * @throws MidiUnavailableException thrown if a receiver is not available
 195      *         due to resource restrictions
 196      * @see Receiver#close()
 197      */
 198     Receiver getReceiver() throws MidiUnavailableException;
 199 
 200     /**
 201      * Returns all currently active, non-closed receivers connected with this
 202      * {@code MidiDevice}. A receiver can be removed from the device by closing
 203      * it.
 204      * <p>
 205      * Usually the returned receivers implement the {@code MidiDeviceReceiver}
 206      * interface.
 207      *
 208      * @return an unmodifiable list of the open receivers
 209      * @since 1.5
 210      */
 211     List<Receiver> getReceivers();
 212 
 213     /**
 214      * Obtains a MIDI OUT connection from which the MIDI device will transmit
 215      * MIDI data. The returned transmitter must be closed when the application
 216      * has finished using it.
 217      * <p>
 218      * Usually the returned transmitter implements the
 219      * {@code MidiDeviceTransmitter} interface.
 220      * <p>
 221      * Obtaining a {@code Transmitter} with this method does not open the
 222      * device. To be able to use the device, it has to be opened explicitly by
 223      * calling {@link #open}. Also, closing the {@code Transmitter} does not
 224      * close the device. It has to be closed explicitly by calling
 225      * {@link #close}.
 226      *
 227      * @return a MIDI OUT transmitter for the device
 228      * @throws MidiUnavailableException thrown if a transmitter is not available
 229      *         due to resource restrictions
 230      * @see Transmitter#close()
 231      */
 232     Transmitter getTransmitter() throws MidiUnavailableException;
 233 
 234     /**
 235      * Returns all currently active, non-closed transmitters connected with this
 236      * {@code MidiDevice}. A transmitter can be removed from the device by
 237      * closing it.
 238      * <p>
 239      * Usually the returned transmitters implement the
 240      * {@code MidiDeviceTransmitter} interface.
 241      *
 242      * @return an unmodifiable list of the open transmitters
 243      * @since 1.5
 244      */
 245     List<Transmitter> getTransmitters();
 246 
 247     /**
 248      * A {@code MidiDevice.Info} object contains assorted data about a
 249      * {@link MidiDevice}, including its name, the company who created it, and
 250      * descriptive text.
 251      *
 252      * @see MidiDevice#getDeviceInfo
 253      */
 254     class Info {
 255 
 256         /**
 257          * The device's name.
 258          */
 259         private final String name;
 260 
 261         /**
 262          * The name of the company who provides the device.
 263          */
 264         private final String vendor;
 265 
 266         /**
 267          * A description of the device.
 268          */
 269         private final String description;
 270 
 271         /**
 272          * Device version.
 273          */
 274         private final String version;
 275 
 276         /**
 277          * Constructs a device info object.
 278          *
 279          * @param  name the name of the device
 280          * @param  vendor the name of the company who provides the device
 281          * @param  description a description of the device
 282          * @param  version version information for the device
 283          */
 284         protected Info(String name, String vendor, String description,
 285                        String version) {
 286 
 287             this.name = name;
 288             this.vendor = vendor;
 289             this.description = description;
 290             this.version = version;
 291         }
 292 
 293         /**
 294          * Indicates whether the specified object is equal to this info object,
 295          * returning {@code true} if the objects are the same.
 296          *
 297          * @param  obj the reference object with which to compare
 298          * @return {@code true} if the specified object is equal to this info
 299          *         object; {@code false} otherwise
 300          */
 301         @Override
 302         public final boolean equals(Object obj) {
 303             return super.equals(obj);
 304         }
 305 
 306         /**
 307          * Returns a hash code value for this info object.
 308          *
 309          * @return a hash code value for this info object
 310          */
 311         @Override
 312         public final int hashCode() {
 313             return super.hashCode();
 314         }
 315 
 316         /**
 317          * Obtains the name of the device.
 318          *
 319          * @return a string containing the device's name
 320          */
 321         public final String getName() {
 322             return name;
 323         }
 324 
 325         /**
 326          * Obtains the name of the company who supplies the device.
 327          *
 328          * @return device the vendor's name
 329          */
 330         public final String getVendor() {
 331             return vendor;
 332         }
 333 
 334         /**
 335          * Obtains the description of the device.
 336          *
 337          * @return a description of the device
 338          */
 339         public final String getDescription() {
 340             return description;
 341         }
 342 
 343         /**
 344          * Obtains the version of the device.
 345          *
 346          * @return textual version information for the device
 347          */
 348         public final String getVersion() {
 349             return version;
 350         }
 351 
 352         /**
 353          * Provides a string representation of the device information.
 354          *
 355          * @return a description of the info object
 356          */
 357         @Override
 358         public final String toString() {
 359             return name;
 360         }
 361     }
 362 }
--- EOF ---