/* * Copyright (c) 1999, 2010, Oracle and/or its affiliates. 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.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ 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 extends AutoCloseable {      /**     * 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>Usually the returned receiver implements     * the {@code MidiDeviceReceiver} interface.     *     * <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.     *     * <p>Usually the returned receivers implement     * the {@code MidiDeviceReceiver} interface.     *     * @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>Usually the returned transmitter implements     * the {@code MidiDeviceTransmitter} interface.     *     * <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.     *     * <p>Usually the returned transmitters implement     * the {@code MidiDeviceTransmitter} interface.     *     * @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  }