[android] 가속도 센서를 이용한 흔듦(Shake) 감지

import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
 
public class ShakeActivity extends Activity implements SensorEventListener
{
 
    private long lastTime;
    private float speed;
    private float lastX;
    private float lastY;
    private float lastZ;
    private float x, y, z;
 
    private static final int SHAKE_THRESHOLD = 800;
    private static final int DATA_X = SensorManager.DATA_X;
    private static final int DATA_Y = SensorManager.DATA_Y;
    private static final int DATA_Z = SensorManager.DATA_Z;
 
    private SensorManager sensorManager;
    private Sensor accelerormeterSensor;
 
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
        accelerormeterSensor =
            sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    }
 
    @Override
    public void onStart() {
        super.onStart();
        if (accelerormeterSensor != null)
            sensorManager.registerListener(this, accelerormeterSensor,
            SensorManager.SENSOR_DELAY_GAME);
    }
 
    @Override
    public void onStop() {
        super.onStop();
        if (sensorManager != null)
            sensorManager.unregisterListener(this);
    }
 
    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
 
    }
 
    @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            long currentTime = System.currentTimeMillis();
            long gabOfTime = (currentTime - lastTime);
            if (gabOfTime > 100) {
                lastTime = currentTime;
                x = event.values[SensorManager.DATA_X];
                y = event.values[SensorManager.DATA_Y];
                z = event.values[SensorManager.DATA_Z];
 
                speed =
                    Math.abs(x + y + z - lastX - lastY - lastZ)
                    / gabOfTime * 10000;
 
                if (speed > SHAKE_THRESHOLD) {
                    // 이벤트발생!!
                }
 
                lastX = event.values[DATA_X];
                lastY = event.values[DATA_Y];
                lastZ = event.values[DATA_Z];
            }
 
        }
 
    }
}