package cgeo.geocaching.sensors;
import cgeo.geocaching.utils.AndroidRxUtils;
import cgeo.geocaching.utils.Log;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import io.reactivex.Observable;
import io.reactivex.ObservableEmitter;
import io.reactivex.ObservableOnSubscribe;
public class MagnetometerAndAccelerometerProvider {
private MagnetometerAndAccelerometerProvider() {
// Utility class, not to be instantiated
}
public static Observable<Float> create(final Context context) {
final SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
final Sensor accelerometerSensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
final Sensor magnetometerSensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
if (magnetometerSensor == null || accelerometerSensor == null) {
return Observable.error(new RuntimeException("no magnetic or accelerometer sensor"));
}
final Observable<Float> observable = Observable.create(new ObservableOnSubscribe<Float>() {
private final float[] lastAccelerometer = new float[3];
private final float[] lastMagnetometer = new float[3];
private boolean lastAccelerometerSet = false;
private boolean lastMagnetometerSet = false;
private final float[] rotateMatrix = new float[9];
private final float[] orientation = new float[3];
@Override
public void subscribe(final ObservableEmitter<Float> emitter) throws Exception {
final SensorEventListener listener = new SensorEventListener() {
@Override
public void onSensorChanged(final SensorEvent sensorEvent) {
if (sensorEvent.sensor.equals(accelerometerSensor)) {
System.arraycopy(sensorEvent.values, 0, lastAccelerometer, 0, sensorEvent.values.length);
lastAccelerometerSet = true;
} else if (sensorEvent.sensor.equals(magnetometerSensor)) {
System.arraycopy(sensorEvent.values, 0, lastMagnetometer, 0, sensorEvent.values.length);
lastMagnetometerSet = true;
}
if (lastAccelerometerSet && lastMagnetometerSet) {
SensorManager.getRotationMatrix(rotateMatrix, null, lastAccelerometer, lastMagnetometer);
SensorManager.getOrientation(rotateMatrix, orientation);
emitter.onNext((float) (orientation[0] * 180 / Math.PI));
}
}
@Override
public void onAccuracyChanged(final Sensor sensor, final int i) {
/*
* There is a bug in Android, which apparently causes this method to be called every
* time the sensor _value_ changed, even if the _accuracy_ did not change. Do not have any code in here.
*
* See for example https://code.google.com/p/android/issues/detail?id=14792
*/
}
};
Log.d("MagnetometerAndAccelerometerProvider: registering listener");
sensorManager.registerListener(listener, accelerometerSensor, SensorManager.SENSOR_DELAY_NORMAL);
sensorManager.registerListener(listener, magnetometerSensor, SensorManager.SENSOR_DELAY_NORMAL);
emitter.setDisposable(AndroidRxUtils.disposeOnCallbacksScheduler(new Runnable() {
@Override
public void run() {
Log.d("MagnetometerAndAccelerometerProvider: unregistering listener");
sensorManager.unregisterListener(listener, accelerometerSensor);
sensorManager.unregisterListener(listener, magnetometerSensor);
}
}));
}
});
return observable.subscribeOn(AndroidRxUtils.looperCallbacksScheduler).share();
}
public static boolean hasMagnetometerAndAccelerometerSensors(final Context context) {
final SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
return sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD) != null &&
sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) != null;
}
}