Android : Get the screen rotation from a BroadcastReceiver

Question

I have a AlarmManager that execute an Intent Broadcast every 5min :

AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setExact(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 300000, PendingIntent.getBroadcast(context, 0, new Intent(context, Sensors.class), 0));

Inside the BroadcastReceiver's onReceive method, I need to know the device orientation (0°, 90°, 180°, 270°) :

int orientation = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getOrientation();

Everything works fine. But when I minimize or close the app, the screen's rotation always returns 0° (orientation of android home screen), even if the device is lying horizontally.

How can I know the device's rotation from a BroadcastReceiver, independently of the app or device's status?

Answer 1

I finally used the accelerometer to solve this problem :

SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);

if (sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) != null) {
final SensorEventListener sensorEventListener = new SensorEventListener() {
    public void onSensorChanged(SensorEvent event) {
        sensorManager.unregisterListener(this);

        int orientation;

        // Vertical
        if (Math.abs(event.values[1]) > Math.abs(event.values[0]) && Math.abs(event.values[1]) > Math.abs(event.values[2]))
            if (event.values[1] > 0)
                orientation = 0; // Head Up
            else
                orientation = 180; // Head Down

        // Horizontal
        else if (Math.abs(event.values[0]) > Math.abs(event.values[1]) && Math.abs(event.values[0]) > Math.abs(event.values[2]))
            if (event.values[0] > 0)
                orientation = 90; // Left
            else
                orientation = 270; // Right

        // Flat
        else
            orientation = 0;
    }

    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
};

sensorManager.registerListener(sensorEventListener, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_FASTEST);
}