How to detect volume button long press in the background while the screen is off?

Question

I know highly similar questions have been asked, yet there are differences. Most questions want to detect single press. Some long press but with the screen enabled. I want to detect long presses in the background also while the screen is off. I want to use it when a media player is active so deep sleep or doze mode is not relevant.

I tried most answers from here: Listen to volume buttons in background service? All of them don't fulfil my requirements. I also tried to use the accessibilityservice, but that does not work when the screen is off.

I am 100% sure it is possible. There is an app on the play store that does it on my Pixel 2. I did some testing and it seems it only actually requires the NotificationListener

Answer 1

You can capture the event easily with a couple of snippets

Register a broadcast reciever

<receiver android:name=".VolumeButtonReceiver">
    <intent-filter>
        <action android:name="android.media.VOLUME_CHANGED_ACTION" />
    </intent-filter>
</receiver>

Bind the event

public class VolumeButtonReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction() != null && intent.getAction().equals("android.media.VOLUME_CHANGED_ACTION")) {
            // Handle volume key event here
        }
    }
}

Getting longpress usually needs some extra work the idea I like is to detect the keydown event and use a counter ( event.startTracking() ) to decide if it's a longpress.

described well in this answer:

onKeyDown and onKeyLongPress

(a very old answer but seems to keep on working with every android update)

This gist is that you starting by tracking the onKeyDown event, set a flag when the longpress event is hit, set a flag to determine if it was longpressed or not, and read that flag in the onKeyUp event.

Additionally you asked about doing this while the screen is off. For that you'll want a "Foreground" Service and Partial wake lock enabled, the docs give better examples than I ever could:

https://developer.android.com/training/scheduling/wakelock

https://developer.android.com/guide/components/foreground-services

Answer 2

i come from javascript background, IMO the basic idea is we need something like debouncing. use the register broadcaster as mentioned by @danielricardo:

<receiver android:name=".VolumeButtonReceiver">
    <intent-filter>
        <action android:name="android.media.VOLUME_CHANGED_ACTION" />
    </intent-filter>
</receiver>

paste this in as receiver class, rename variables acc to your needs:

public class VolumeButtonReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals("android.media.VOLUME_CHANGED_ACTION")) {
            int volumeState = intent.getIntExtra("android.media.EXTRA_VOLUME_STATE", -1);
            if (volumeState == 1) { // Volume button down
                Intent i = new Intent(context, LongPressService.class);
                i.putExtra("volumeButtonAction", 0);
                context.startService(i);
            } else if (volumeState == 0) { // Volume button up
                Intent i = new Intent(context, LongPressService.class);
                i.putExtra("volumeButtonAction", 1);
                context.startService(i);
            }
        }
    }
}

create a long press service:

public class LongPressService extends Service {
    private boolean isVolumeButtonLongPress = false;
    private Handler handler = new Handler();
    private long pressStartTime = 0;

    private Runnable longPressRunnable = new Runnable() {
        @Override
        public void run() {
            if (isVolumeButtonLongPress) {
                long pressDuration = System.currentTimeMillis() - pressStartTime;
                if (pressDuration >= 1000) {
                    int volumeButtonAction = getIntent().getIntExtra("volumeButtonAction", -1);
                    if (volumeButtonAction == 0) {
                        myCustomFunctionDown();
                    } else if (volumeButtonAction == 1) {
                        myCustomFunctionUp();
                    }
                }
            }
        }
    };

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (intent != null) {
            int volumeButtonAction = intent.getIntExtra("volumeButtonAction", -1);
            if (volumeButtonAction != -1) {
                isVolumeButtonLongPress = true;
                pressStartTime = System.currentTimeMillis();
                handler.postDelayed(longPressRunnable, 1000); // Debounce threshold
            }
        } else {
            handler.removeCallbacks(longPressRunnable);
            isVolumeButtonLongPress = false;
        }

        return START_STICKY;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    private void myCustomFunctionDown() {
        // Call your custom function for volume down long press here
    }

    private void myCustomFunctionUp() {
        // Call your custom function for volume up long press here
    }
}

Answer 3

As I understand your question, you want to:

1. Detect long presses in the background (some other apps are still running, and the screen is ON?)
2. Detect long presses while the SCREEN is OFF

for booth case, a MEDIA PLAYER is ACTIVE

As it is writen in Android documentation

In previous version of Android, detecting touch events while the screen is off is not possible in Android due to security reasons.

But there are some exceptions, like music players apps, not all media players.

But actually, Touch event is easily detected in some phone like Pixel 5.

it is possible to detect touch events while the screen is off using a Service and a WakeLock. So you have to check the docs, for what version of android you are working on.

If you are using recent android, You may try this code:

public class VolumeButtonReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals("android.media.VOLUME_CHANGED_ACTION")) {
            int streamType = intent.getIntExtra("android.media.EXTRA_VOLUME_STREAM_TYPE", -1);
            if (streamType == AudioManager.STREAM_MUSIC) {
                int oldVolume = intent.getIntExtra("android.media.EXTRA_PREV_VOLUME_STREAM_VALUE", -1);
                int newVolume = intent.getIntExtra("android.media.EXTRA_VOLUME_STREAM_VALUE", -1);
                if (newVolume < oldVolume) {
                    // Volume button was long-pressed
                }
            }
        }
    }
}

This code creates a BroadcastReceiver that listens for the android.media.VOLUME_CHANGED_ACTION intent. When this intent is received, it checks whether the volume stream type is STREAM_MUSIC, which corresponds to the media volume.