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 input device provider. 32 * 33 * @author Kara Kytle 34 * @author Florian Bomers 35 */ 36 public final class MidiInDeviceProvider 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 input 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 */ MidiInDeviceProvider()55 public MidiInDeviceProvider() { 56 } 57 58 // implementation of abstract methods in AbstractMidiDeviceProvider 59 60 @Override createInfo(int index)61 AbstractMidiDeviceProvider.Info createInfo(int index) { 62 if (!enabled) { 63 return null; 64 } 65 return new MidiInDeviceInfo(index, MidiInDeviceProvider.class); 66 } 67 68 @Override createDevice(AbstractMidiDeviceProvider.Info info)69 MidiDevice createDevice(AbstractMidiDeviceProvider.Info info) { 70 if (enabled && (info instanceof MidiInDeviceInfo)) { 71 return new MidiInDevice(info); 72 } 73 return null; 74 } 75 76 @Override getNumDevices()77 int getNumDevices() { 78 if (!enabled) { 79 return 0; 80 } 81 int numDevices = nGetNumDevices(); 82 return numDevices; 83 } 84 85 @Override getDeviceCache()86 MidiDevice[] getDeviceCache() { return devices; } 87 @Override setDeviceCache(MidiDevice[] devices)88 void setDeviceCache(MidiDevice[] devices) { MidiInDeviceProvider.devices = devices; } 89 @Override getInfoCache()90 Info[] getInfoCache() { return infos; } 91 @Override setInfoCache(Info[] infos)92 void setInfoCache(Info[] infos) { MidiInDeviceProvider.infos = infos; } 93 94 /** 95 * Info class for MidiInDevices. Adds the 96 * provider's Class to keep the provider class from being 97 * unloaded. Otherwise, at least on JDK1.1.7 and 1.1.8, 98 * the provider class can be unloaded. Then, then the provider 99 * is next invoked, the static block is executed again and a new 100 * instance of the device object is created. Even though the 101 * previous instance may still exist and be open / in use / etc., 102 * the new instance will not reflect that state... 103 */ 104 static final class MidiInDeviceInfo extends AbstractMidiDeviceProvider.Info { 105 private final Class<?> providerClass; 106 MidiInDeviceInfo(int index, Class<?> providerClass)107 private MidiInDeviceInfo(int index, Class<?> providerClass) { 108 super(nGetName(index), nGetVendor(index), nGetDescription(index), nGetVersion(index), index); 109 this.providerClass = providerClass; 110 } 111 112 } // class MidiInDeviceInfo 113 nGetNumDevices()114 private static native int nGetNumDevices(); nGetName(int index)115 private static native String nGetName(int index); nGetVendor(int index)116 private static native String nGetVendor(int index); nGetDescription(int index)117 private static native String nGetDescription(int index); nGetVersion(int index)118 private static native String nGetVersion(int index); 119 } 120