1/*
2 * Copyright (c) 1999, 2014, 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
26package com.sun.media.sound;
27
28import javax.sound.midi.MidiDevice;
29
30/**
31 * MIDI output device provider.
32 *
33 * @author Kara Kytle
34 * @author Florian Bomers
35 */
36public 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
48        Platform.initialize();
49        enabled = Platform.isMidiIOEnabled();
50    }
51
52    /**
53     * Required public no-arg constructor.
54     */
55    public MidiOutDeviceProvider() {
56        if (Printer.trace) Printer.trace("MidiOutDeviceProvider: constructor");
57    }
58
59    @Override
60    AbstractMidiDeviceProvider.Info createInfo(int index) {
61        if (!enabled) {
62            return null;
63        }
64        return new MidiOutDeviceInfo(index, MidiOutDeviceProvider.class);
65    }
66
67    @Override
68    MidiDevice createDevice(AbstractMidiDeviceProvider.Info info) {
69        if (enabled && (info instanceof MidiOutDeviceInfo)) {
70            return new MidiOutDevice(info);
71        }
72        return null;
73    }
74
75    @Override
76    int getNumDevices() {
77        if (!enabled) {
78            if (Printer.debug)Printer.debug("MidiOutDevice not enabled, returning 0 devices");
79            return 0;
80        }
81        return nGetNumDevices();
82    }
83
84    @Override
85    MidiDevice[] getDeviceCache() { return devices; }
86    @Override
87    void setDeviceCache(MidiDevice[] devices) { MidiOutDeviceProvider.devices = devices; }
88    @Override
89    Info[] getInfoCache() { return infos; }
90    @Override
91    void setInfoCache(Info[] infos) { MidiOutDeviceProvider.infos = infos; }
92
93    /**
94     * Info class for MidiOutDevices.  Adds the
95     * provider's Class to keep the provider class from being
96     * unloaded.  Otherwise, at least on JDK1.1.7 and 1.1.8,
97     * the provider class can be unloaded.  Then, then the provider
98     * is next invoked, the static block is executed again and a new
99     * instance of the device object is created.  Even though the
100     * previous instance may still exist and be open / in use / etc.,
101     * the new instance will not reflect that state...
102     */
103    static final class MidiOutDeviceInfo extends AbstractMidiDeviceProvider.Info {
104        private final Class<?> providerClass;
105
106        private MidiOutDeviceInfo(int index, Class<?> providerClass) {
107            super(nGetName(index), nGetVendor(index), nGetDescription(index), nGetVersion(index), index);
108            this.providerClass = providerClass;
109        }
110
111    } // class MidiOutDeviceInfo
112
113    private static native int nGetNumDevices();
114    private static native String nGetName(int index);
115    private static native String nGetVendor(int index);
116    private static native String nGetDescription(int index);
117    private static native String nGetVersion(int index);
118}
119