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 input device provider.
32 *
33 * @author Kara Kytle
34 * @author Florian Bomers
35 */
36public 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
48        Platform.initialize();
49        enabled = Platform.isMidiIOEnabled();
50    }
51
52    /**
53     * Required public no-arg constructor.
54     */
55    public MidiInDeviceProvider() {
56        if (Printer.trace) Printer.trace("MidiInDeviceProvider: constructor");
57    }
58
59    // implementation of abstract methods in AbstractMidiDeviceProvider
60
61    @Override
62    AbstractMidiDeviceProvider.Info createInfo(int index) {
63        if (!enabled) {
64            return null;
65        }
66        return new MidiInDeviceInfo(index, MidiInDeviceProvider.class);
67    }
68
69    @Override
70    MidiDevice createDevice(AbstractMidiDeviceProvider.Info info) {
71        if (enabled && (info instanceof MidiInDeviceInfo)) {
72            return new MidiInDevice(info);
73        }
74        return null;
75    }
76
77    @Override
78    int getNumDevices() {
79        if (!enabled) {
80            if (Printer.debug)Printer.debug("MidiInDevice not enabled, returning 0 devices");
81            return 0;
82        }
83        int numDevices = nGetNumDevices();
84        if (Printer.debug)Printer.debug("MidiInDeviceProvider.getNumDevices(): devices: " + numDevices);
85        return numDevices;
86    }
87
88    @Override
89    MidiDevice[] getDeviceCache() { return devices; }
90    @Override
91    void setDeviceCache(MidiDevice[] devices) { MidiInDeviceProvider.devices = devices; }
92    @Override
93    Info[] getInfoCache() { return infos; }
94    @Override
95    void setInfoCache(Info[] infos) { MidiInDeviceProvider.infos = infos; }
96
97    /**
98     * Info class for MidiInDevices.  Adds the
99     * provider's Class to keep the provider class from being
100     * unloaded.  Otherwise, at least on JDK1.1.7 and 1.1.8,
101     * the provider class can be unloaded.  Then, then the provider
102     * is next invoked, the static block is executed again and a new
103     * instance of the device object is created.  Even though the
104     * previous instance may still exist and be open / in use / etc.,
105     * the new instance will not reflect that state...
106     */
107    static final class MidiInDeviceInfo extends AbstractMidiDeviceProvider.Info {
108        private final Class<?> providerClass;
109
110        private MidiInDeviceInfo(int index, Class<?> providerClass) {
111            super(nGetName(index), nGetVendor(index), nGetDescription(index), nGetVersion(index), index);
112            this.providerClass = providerClass;
113        }
114
115    } // class MidiInDeviceInfo
116
117    private static native int nGetNumDevices();
118    private static native String nGetName(int index);
119    private static native String nGetVendor(int index);
120    private static native String nGetDescription(int index);
121    private static native String nGetVersion(int index);
122}
123