audio - Detecting whether a headset is plugged into an Android device or not.

Question

How can I determine whether a headset is plugged into an Android device or not?

Answer 1

You can use the broadcast receiver.

So, You might write this code in "AndroidManifest.xml"

<receiver android:name="com.juno.brheadset.HeadsetStateReceiver">
    <intent-filter>
        <action android:name="android.intent.action.HEADSET_PLUG"/>
    </intent-filter>
</receiver>-->

But, This doesn't work. When OS send this "HEADSET_PLUG" intent, OS set the flag "Intent.FLAG_RECEIVER_REGISTERED_ONLY" So, You should write the code like below in Activity or Service class instead of "AndroidManifest" things.

public class BRHeadsetActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    IntentFilter receiverFilter = new IntentFilter(Intent.ACTION_HEADSET_PLUG);
    HeadsetStateReceiver receiver = new HeadsetStateReceiver();
    registerReceiver( receiver, receiverFilter );


}

I hope this article help you. Bye!

This is the part of "HeadsetObserver.java", Android SDK Source.

private final void sendIntent(int headset, int headsetState, int prevHeadsetState, String headsetName) {
    if ((headsetState & headset) != (prevHeadsetState & headset)) {
        //  Pack up the values and broadcast them to everyone
        Intent intent = new Intent(Intent.ACTION_HEADSET_PLUG);

        **intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);**

        int state = 0;
        int microphone = 0;

        if ((headset & HEADSETS_WITH_MIC) != 0) {
            microphone = 1;
        }
        if ((headsetState & headset) != 0) {
            state = 1;
        }
        intent.putExtra("state", state);
        intent.putExtra("name", headsetName);
        intent.putExtra("microphone", microphone);

        if (LOG) Slog.v(TAG, "Intent.ACTION_HEADSET_PLUG: state: "+state+" name: "+headsetName+" mic: "+microphone);
        // TODO: Should we require a permission?
        ActivityManagerNative.broadcastStickyIntent(intent, null);
    }
}