MIDI docs: use getPorts()

<p>The Android MIDI package allows users to:</p>

<p>The Android MIDI package allows users to:</p>

<ul>

<ul>

  <li> Connect a MIDI keyboard to Android to play a synthesizer or drive music apps.

  <li> Connect a MIDI keyboard to Android to play a synthesizer or drive music apps.</li>

  <li> Connect alternative MIDI controllers to Android.

  <li> Connect alternative MIDI controllers to Android.</li>

  <li> Drive external MIDI synths from Android.

  <li> Drive external MIDI synths from Android.</li>

  <li> Drive external peripherals, lights, show control, etc from Android.

  <li> Drive external peripherals, lights, show control, etc from Android.</li>

  <li> Generate music dynamically from games or music creation apps.

  <li> Generate music dynamically from games or music creation apps.</li>

  <li> Generate MIDI messages in one app and send them to a second app.

  <li> Generate MIDI messages in one app and send them to a second app.</li>

  <li> Use an Android device running in <em>peripheral mode</em> as a multitouch controller connected to a laptop.

  <li> Use an Android device running in <em>peripheral mode</em> as a multitouch controller

  connected to a laptop.</li>

</ul>

</ul>

<h2 id=the_api_features_include>The API features include:</h2>

<h2 id=the_api_features_include>The API features include:</h2>

<ul>

<ul>

  <li> Enumeration of currently available devices. Information includes name, vendor,

  <li> Enumeration of currently available devices. Information includes name, vendor,

capabilities, etc.

capabilities, etc.</li>

  <li> Provide notification when MIDI devices are plugged in or unplugged.

  <li> Provide notification when MIDI devices are plugged in or unplugged.</li>

  <li> Support efficient transmission of single or multiple short 1-3 byte MIDI

  <li> Support efficient transmission of single or multiple short 1-3 byte MIDI messages.</li>

messages.

  <li> Support transmission of arbitrary length data for SysEx, etc.</li>

  <li> Support transmission of arbitrary length data for SysEx, etc.

  <li> Timestamps to avoid jitter.</li>

  <li> Timestamps to avoid jitter.

  <li> Support creation of <em>virtual MIDI devices</em> that can be connected to other devices.

  <li> Support direction connection or &ldquo;patching&rdquo; of devices for lower latency.

  An example might be a synthesizer app that can be controlled by a composing app.</li>

  <li> Support direction connection or &ldquo;patching&rdquo; of devices for lower latency.</li>

</ul>

</ul>

<h2 id=transports_supported>Transports Supported</h2>

<h2 id=transports_supported>Transports Supported</h2>

<h1 id=writing_a_midi_application>Writing a MIDI Application</h1>

<h1 id=writing_a_midi_application>Writing a MIDI Application</h1>

<h2 id=manifest_feature>Declare Feature in Manifest</h2>

<p>An app that requires the MIDI API should declare that in the AndroidManifest.xml file.

Then the app will not appear in the Play Store for old devices that do not support the MIDI API.</p>

<pre class=prettyprint>

<uses-feature android:name="android.software.midi" android:required="true"/>

</pre>

<h2 id=the_midimanager>The MidiManager</h2>

<h2 id=the_midimanager>The MidiManager</h2>

<p>Other properties include PROPERTY_PRODUCT, PROPERTY_NAME,

<p>Other properties include PROPERTY_PRODUCT, PROPERTY_NAME,

PROPERTY_SERIAL_NUMBER</p>

PROPERTY_SERIAL_NUMBER</p>

<p>You can get the names of the ports from a PortInfo object.</p>

<p>You can get the names and types of the ports from a PortInfo object.

The type will be either TYPE_INPUT or TYPE_OUTPUT.</p>

<pre class=prettyprint>

<pre class=prettyprint>

PortInfo portInfo = info.getInputPortInfo(i);

MidiDeviceInfo.PortInfo[] portInfos = info.getPorts();

String portName = portInfo.getName();

String portName = portInfos[0].getName();

if (portInfos[0].getType() == MidiDeviceInfo.PortInfo.TYPE_INPUT) {

    ...

}

</pre>

</pre>

<p>Here we send a message with a timestamp 2 seconds in the future.</p>

<p>Here we send a message with a timestamp 2 seconds in the future.</p>

<pre class=prettyprint>

<pre class=prettyprint>

final long NANOS_PER_SECOND = 1000000000L;

long now = System.nanoTime();

long now = System.nanoTime();

long future = now + (2 * 1000000000);

long future = now + (2 * NANOS_PER_SECOND);

inputPort.send(buffer, offset, numBytes, future);

inputPort.send(buffer, offset, numBytes, future);

</pre>

</pre>

<p>The details of the resource in this example is stored in

<p>The details of the resource in this example is stored in

&ldquo;res/xml/synth_device_info.xml&rdquo;.</p>

“res/xml/synth_device_info.xml”. The port names that you

declare in this file will be available from PortInfo.getName().</p>

<pre class=prettyprint>

<pre class=prettyprint>

<devices>

<devices>

public class MidiSynthDeviceService extends MidiDeviceService {

public class MidiSynthDeviceService extends MidiDeviceService {

    private static final String TAG = "MidiSynthDeviceService";

    private static final String TAG = "MidiSynthDeviceService";

    private MySynthEngine mSynthEngine = new MySynthEngine();

    private MySynthEngine mSynthEngine = new MySynthEngine();

    private boolean synthStarted = false;

    @Override

    @Override

    public void onCreate() {

    public void onCreate() {

        super.onCreate();

        super.onCreate();

     */

     */

    @Override

    @Override

    public void onDeviceStatusChanged(MidiDeviceStatus status) {

    public void onDeviceStatusChanged(MidiDeviceStatus status) {

        if (status.isInputPortOpen(0)) {

        if (status.isInputPortOpen(0) && !synthStarted) {

            mSynthEngine.start();

            mSynthEngine.start();

        } else {

            synthStarted = true;

        } else if (!status.isInputPortOpen(0) && synthStarted){

            mSynthEngine.stop();

            mSynthEngine.stop();

            synthStarted = false;

        }

        }

    }

    }

}

}