Android power save mode listener?

Question

How can an Android listener be created to perform a task just before entering power save mode? Also: what are some of the low power options that can be controlled by this ta

Answer 1

The answer above(for API 21 and above) is not exactly right. You should register a receiver in your activity or service like this:

BroadcastReceiver powerSaverChangeReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        checkPowerSaverMode();
    }
 };

IntentFilter filter = new IntentFilter();
filter.addAction("android.os.action.POWER_SAVE_MODE_CHANGED");
registerReceiver(powerSaverChangeReceiver, filter);

The reason for this is that receivers in manifest are not triggered by this broadcast.

ACTION_POWER_SAVE_MODE_CHANGED

Intent that is broadcast when the state of isPowerSaveMode() changes. This broadcast is only sent to registered receivers.

I have tested this and it works.

Answer 2

How can an Android listener be created to perform a task just before entering power save mode?

There is no broadcast Intent for this. The closest is ACTION_SCREEN_OFF. The device will likely fall asleep in the near future after you receive this broadcast. And, you can only listen for this broadcast using a BroadcastReceiver registered via registerReceiver() in an activity or service or other Context.

Also: what are some of the low power options that can be controlled by this task?

I have no idea what this means, sorry.

Answer 3

Since Lollipop (API 21) there is PowerManager#ACTION_POWER_SAVE_MODE_CHANGED broadcast intent.

So you need just to receive it:

---

AndroidManifest.xml:

<receiver android:name=".observers.PowerSaveModeReceiver">
    <intent-filter>
        <action android:name="android.os.action.POWER_SAVE_MODE_CHANGED"/> 
    </intent-filter>
</receiver>

---

PowerSaveModeReceiver.java:

public class PowerSaveModeReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(final Context context, final Intent intent) {
        if (BuildConfig.DEV_LOGS)
            Log.d(this.getClass().getName(), String.format("onReceive(context = [%s], intent = [%s])", context, intent));

        final PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        if (pm.isPowerSaveMode()) {
            // do something
        } else {
            // do some else
        }
    }
}