Hinge angle sensor API

The hinge angle is a value from 0 to 360:

• 0 - device is closed (screens are facing each other, and not visible)
• 90 - device is an "L" shape, also known as the laptop posture or book posture depending on orientation
• 180 - device is flat
• 360 - device is folded so that the screens are facing away from each other and only one screen is operating

Tip

This code sample is written for the hinge angle sensor on the Surface Duo.

The Jetpack Window Manager has a DeviceState API that provides information about posture (eg. closed, open, half-open) that works on devices from multiple manufacturers.

Code example

Kotlin

The hinge angle can be measured using Android's sensor manager configured with the Hinge Angle sensor name.

private val HINGE_ANGLE_SENSOR_NAME = "Hinge Angle"

private var mSensorManager: SensorManager? = null
private var mHingeAngleSensor: Sensor? = null
private var mSensorListener: SensorEventListener? = null

// call setupSensors from onCreate
private fun setupSensors() {
    mSensorManager = getSystemService(SENSOR_SERVICE) as SensorManager
    val sensorList: List<Sensor> = mSensorManager!!.getSensorList(Sensor.TYPE_ALL)
    for (sensor in sensorList) {
        if (sensor.getName().contains(HINGE_ANGLE_SENSOR_NAME)) {
            mHingeAngleSensor = sensor
        }
    }
    mSensorListener = object : SensorEventListener {
        override fun onSensorChanged(event: SensorEvent) {
            if (event.sensor == mHingeAngleSensor) {
                val angle = event.values[0].toInt()
                //TODO something with angle
            }
        }

        override fun onAccuracyChanged(sensor: Sensor?, accuracy: Int) {
            //TODO (if required)
        }
    }
}

override fun onPause() {
    super.onPause()
    if (mHingeAngleSensor != null) {
        mSensorManager?.unregisterListener(mSensorListener, mHingeAngleSensor)
    }
}

override fun onResume() {
    super.onResume()
    if (mHingeAngleSensor != null) {
        mSensorManager?.registerListener(
            mSensorListener,
            mHingeAngleSensor,
            SensorManager.SENSOR_DELAY_NORMAL
        )
    }
}

Java

Exposed via Hinge Angle sensor and using SensorEventListener().

private static final String HINGE_ANGLE_SENSOR_NAME = "Hinge Angle";

private SensorManager mSensorManager;
private Sensor mHingeAngleSensor;
private SensorEventListener mSensorListener;

// call setupSensors from onCreate
private void setupSensors() {
    mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    List<Sensor> sensorList = mSensorManager.getSensorList(Sensor.TYPE_ALL);

    for (Sensor sensor : sensorList) {
        if (sensor.getName().contains(HINGE_ANGLE_SENSOR_NAME)) {
            mHingeAngleSensor = sensor;
        }
    }

    mSensorListener = new SensorEventListener() {
        @Override
        public void onSensorChanged(final SensorEvent event) {
            if (event.sensor == mHingeAngleSensor) {
                int angle = (int) event.values[0];
                //do something with angle
            }
        }

        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {
            //TODO
        }
    };
}

@Override
protected void onPause() {
    super.onPause();
    if(mHingeAngleSensor !=null) {
        mSensorManager.unregisterListener(mSensorListener,mHingeAngleSensor);
    }
}

@Override
protected void onResume() {
    super.onResume();
    if(mHingeAngleSensor !=null) {
        mSensorManager.registerListener(mSensorListener, mHingeAngleSensor, SensorManager.SENSOR_DELAY_NORMAL);
    }
}