1 /* 2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. 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. 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. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.media.sound; 27 28 import javax.sound.midi.MidiDevice; 29 30 /** 31 * MIDI output device provider. 32 * 33 * @author Kara Kytle 34 * @author Florian Bomers 35 */ 36 public final class MidiOutDeviceProvider extends AbstractMidiDeviceProvider { 37 38 /** Cache of info objects for all MIDI output devices on the system. */ 39 private static Info[] infos = null; 40 41 /** Cache of open MIDI output devices on the system. */ 42 private static MidiDevice[] devices = null; 43 44 private static final boolean enabled; 45 46 static { 47 // initialize Platform.initialize()48 Platform.initialize(); 49 enabled = Platform.isMidiIOEnabled(); 50 } 51 52 /** 53 * Required public no-arg constructor. 54 */ MidiOutDeviceProvider()55 public MidiOutDeviceProvider() { 56 } 57 58 @Override createInfo(int index)59 AbstractMidiDeviceProvider.Info createInfo(int index) { 60 if (!enabled) { 61 return null; 62 } 63 return new MidiOutDeviceInfo(index, MidiOutDeviceProvider.class); 64 } 65 66 @Override createDevice(AbstractMidiDeviceProvider.Info info)67 MidiDevice createDevice(AbstractMidiDeviceProvider.Info info) { 68 if (enabled && (info instanceof MidiOutDeviceInfo)) { 69 return new MidiOutDevice(info); 70 } 71 return null; 72 } 73 74 @Override getNumDevices()75 int getNumDevices() { 76 if (!enabled) { 77 return 0; 78 } 79 return nGetNumDevices(); 80 } 81 82 @Override getDeviceCache()83 MidiDevice[] getDeviceCache() { return devices; } 84 @Override setDeviceCache(MidiDevice[] devices)85 void setDeviceCache(MidiDevice[] devices) { MidiOutDeviceProvider.devices = devices; } 86 @Override getInfoCache()87 Info[] getInfoCache() { return infos; } 88 @Override setInfoCache(Info[] infos)89 void setInfoCache(Info[] infos) { MidiOutDeviceProvider.infos = infos; } 90 91 /** 92 * Info class for MidiOutDevices. Adds the 93 * provider's Class to keep the provider class from being 94 * unloaded. Otherwise, at least on JDK1.1.7 and 1.1.8, 95 * the provider class can be unloaded. Then, then the provider 96 * is next invoked, the static block is executed again and a new 97 * instance of the device object is created. Even though the 98 * previous instance may still exist and be open / in use / etc., 99 * the new instance will not reflect that state... 100 */ 101 static final class MidiOutDeviceInfo extends AbstractMidiDeviceProvider.Info { 102 private final Class<?> providerClass; 103 MidiOutDeviceInfo(int index, Class<?> providerClass)104 private MidiOutDeviceInfo(int index, Class<?> providerClass) { 105 super(nGetName(index), nGetVendor(index), nGetDescription(index), nGetVersion(index), index); 106 this.providerClass = providerClass; 107 } 108 109 } // class MidiOutDeviceInfo 110 nGetNumDevices()111 private static native int nGetNumDevices(); nGetName(int index)112 private static native String nGetName(int index); nGetVendor(int index)113 private static native String nGetVendor(int index); nGetDescription(int index)114 private static native String nGetDescription(int index); nGetVersion(int index)115 private static native String nGetVersion(int index); 116 } 117