/*
* Copyright 1999-2003 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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*/
package javax.sound.midi;
import java.util.List;
/**
* <code>MidiDevice</code> is the base interface for all MIDI devices.
* Common devices include synthesizers, sequencers, MIDI input ports, and MIDI
* output ports.
*
* <p>A <code>MidiDevice</code> can be a transmitter or a receiver of
* MIDI events, or both. Therefore, it can provide {@link Transmitter}
* or {@link Receiver} instances (or both). Typically, MIDI IN ports
* provide transmitters, MIDI OUT ports and synthesizers provide
* receivers. A Sequencer typically provides transmitters for playback
* and receivers for recording.
*
* <p>A <code>MidiDevice</code> can be opened and closed explicitly as
* well as implicitly. Explicit opening is accomplished by calling
* {@link #open}, explicit closing is done by calling {@link
* #close} on the <code>MidiDevice</code> instance.
* If an application opens a <code>MidiDevice</code>
* explicitly, it has to close it explicitly to free system resources
* and enable the application to exit cleanly. Implicit opening is
* done by calling {@link javax.sound.midi.MidiSystem#getReceiver
* MidiSystem.getReceiver} and {@link
* javax.sound.midi.MidiSystem#getTransmitter
* MidiSystem.getTransmitter}. The <code>MidiDevice</code> used by
* <code>MidiSystem.getReceiver</code> and
* <code>MidiSystem.getTransmitter</code> is implementation-dependant
* unless the properties <code>javax.sound.midi.Receiver</code>
* and <code>javax.sound.midi.Transmitter</code> are used (see the
* description of properties to select default providers in
* {@link javax.sound.midi.MidiSystem}). A <code>MidiDevice</code>
* that was opened implicitly, is closed implicitly by closing the
* <code>Receiver</code> or <code>Transmitter</code> that resulted in
* opening it. If more than one implicitly opening
* <code>Receiver</code> or <code>Transmitter</code> were obtained by
* the application, the decive is closed after the last
* <code>Receiver</code> or <code>Transmitter</code> has been
* closed. On the other hand, calling <code>getReceiver</code> or
* <code>getTransmitter</code> on the device instance directly does
* not open the device implicitly. Closing these
* <code>Transmitter</code>s and <code>Receiver</code>s does not close
* the device implicitly. To use a device with <code>Receiver</code>s
* or <code>Transmitter</code>s obtained this way, the device has to
* be opened and closed explicitly.
*
* <p>If implicit and explicit opening and closing are mixed on the
* same <code>MidiDevice</code> instance, the following rules apply:
*
* <ul>
* <li>After an explicit open (either before or after implicit
* opens), the device will not be closed by implicit closing. The only
* way to close an explicitly opened device is an explicit close.</li>
*
* <li>An explicit close always closes the device, even if it also has
* been opened implicitly. A subsequent implicit close has no further
* effect.</li>
* </ul>
*
* To detect if a MidiDevice represents a hardware MIDI port, the
* following programming technique can be used:
*
* <pre>
* MidiDevice device = ...;
* if ( ! (device instanceof Sequencer) && ! (device instanceof Synthesizer)) {
* // we're now sure that device represents a MIDI port
* // ...
* }
* </pre>
*
* <p>
* A <code>MidiDevice</code> includes a <code>{@link MidiDevice.Info}</code> object
* to provide manufacturer information and so on.
*
* @see Synthesizer
* @see Sequencer
* @see Receiver
* @see Transmitter
*
* @author Kara Kytle
* @author Florian Bomers
*/
public interface MidiDevice {
/**
* Obtains information about the device, including its Java class and
* <code>Strings</code> containing its name, vendor, and description.
*
* @return device info
*/
public Info getDeviceInfo();
/**
* Opens the device, indicating that it should now acquire any
* system resources it requires and become operational.
*
* <p>An application opening a device explicitly with this call
* has to close the device by calling {@link #close}. This is
* necessary to release system resources and allow applications to
* exit cleanly.
*
* <p>
* Note that some devices, once closed, cannot be reopened. Attempts
* to reopen such a device will always result in a MidiUnavailableException.
*
* @throws MidiUnavailableException thrown if the device cannot be
* opened due to resource restrictions.
* @throws SecurityException thrown if the device cannot be
* opened due to security restrictions.
*
* @see #close
* @see #isOpen
*/
public void open() throws MidiUnavailableException;
/**
* Closes the device, indicating that the device should now release
* any system resources it is using.
*
* <p>All <code>Receiver</code> and <code>Transmitter</code> instances
* open from this device are closed. This includes instances retrieved
* via <code>MidiSystem</code>.
*
* @see #open
* @see #isOpen
*/
public void close();
/**
* Reports whether the device is open.
*
* @return <code>true</code> if the device is open, otherwise
* <code>false</code>
* @see #open
* @see #close
*/
public boolean isOpen();
/**
* Obtains the current time-stamp of the device, in microseconds.
* If a device supports time-stamps, it should start counting at
* 0 when the device is opened and continue incrementing its
* time-stamp in microseconds until the device is closed.
* If it does not support time-stamps, it should always return
* -1.
* @return the current time-stamp of the device in microseconds,
* or -1 if time-stamping is not supported by the device.
*/
public long getMicrosecondPosition();
/**
* Obtains the maximum number of MIDI IN connections available on this
* MIDI device for receiving MIDI data.
* @return maximum number of MIDI IN connections,
* or -1 if an unlimited number of connections is available.
*/
public int getMaxReceivers();
/**
* Obtains the maximum number of MIDI OUT connections available on this
* MIDI device for transmitting MIDI data.
* @return maximum number of MIDI OUT connections,
* or -1 if an unlimited number of connections is available.
*/
public int getMaxTransmitters();
/**
* Obtains a MIDI IN receiver through which the MIDI device may receive
* MIDI data. The returned receiver must be closed when the application
* has finished using it.
*
* <p>Obtaining a <code>Receiver</code> with this method does not
* open the device. To be able to use the device, it has to be
* opened explicitly by calling {@link #open}. Also, closing the
* <code>Receiver</code> does not close the device. It has to be
* closed explicitly by calling {@link #close}.
*
* @return a receiver for the device.
* @throws MidiUnavailableException thrown if a receiver is not available
* due to resource restrictions
* @see Receiver#close()
*/
public Receiver getReceiver() throws MidiUnavailableException;
/**
* Returns all currently active, non-closed receivers
* connected with this MidiDevice.
* A receiver can be removed
* from the device by closing it.
* @return an unmodifiable list of the open receivers
* @since 1.5
*/
List<Receiver> getReceivers();
/**
* Obtains a MIDI OUT connection from which the MIDI device will transmit
* MIDI data The returned transmitter must be closed when the application
* has finished using it.
*
* <p>Obtaining a <code>Transmitter</code> with this method does not
* open the device. To be able to use the device, it has to be
* opened explicitly by calling {@link #open}. Also, closing the
* <code>Transmitter</code> does not close the device. It has to be
* closed explicitly by calling {@link #close}.
*
* @return a MIDI OUT transmitter for the device.
* @throws MidiUnavailableException thrown if a transmitter is not available
* due to resource restrictions
* @see Transmitter#close()
*/
public Transmitter getTransmitter() throws MidiUnavailableException;
/**
* Returns all currently active, non-closed transmitters
* connected with this MidiDevice.
* A transmitter can be removed
* from the device by closing it.
* @return an unmodifiable list of the open transmitters
* @since 1.5
*/
List<Transmitter> getTransmitters();
/**
* A <code>MidiDevice.Info</code> object contains assorted
* data about a <code>{@link MidiDevice}</code>, including its
* name, the company who created it, and descriptive text.
*
* @see MidiDevice#getDeviceInfo
*/
public static class Info {
/**
* The device's name.
*/
private String name;
/**
* The name of the company who provides the device.
*/
private String vendor;
/**
* A description of the device.
*/
private String description;
/**
* Device version.
*/
private String version;
/**
* Constructs a device info object.
*
* @param name the name of the device
* @param vendor the name of the company who provides the device
* @param description a description of the device
* @param version version information for the device
*/
protected Info(String name, String vendor, String description, String version) {
this.name = name;
this.vendor = vendor;
this.description = description;
this.version = version;
}
/**
* Reports whether two objects are equal.
* Returns <code>true</code> if the objects are identical.
* @param obj the reference object with which to compare this
* object
* @return <code>true</code> if this object is the same as the
* <code>obj</code> argument; <code>false</code> otherwise
*/
public final boolean equals(Object obj) {
return super.equals(obj);
}
/**
* Finalizes the hashcode method.
*/
public final int hashCode() {
return super.hashCode();
}
/**
* Obtains the name of the device.
*
* @return a string containing the device's name
*/
public final String getName() {
return name;
}
/**
* Obtains the name of the company who supplies the device.
* @return device the vendor's name
*/
public final String getVendor() {
return vendor;
}
/**
* Obtains the description of the device.
* @return a description of the device
*/
public final String getDescription() {
return description;
}
/**
* Obtains the version of the device.
* @return textual version information for the device.
*/
public final String getVersion() {
return version;
}
/**
* Provides a string representation of the device information.
* @return a description of the info object
*/
public final String toString() {
return name;
}
} // class Info
}