When I was implementing the shake-to-shuffle feature in Pair-Up game, I googled for a similar code-snippet but didn’t have much luck. Eventually I came across this hidden code in Android Developer Guide which talks about using the phone motion sensor to program:
http://developer.android.com/guide/samples/ApiDemos/src/com/example/android/apis/os/Sensors.html
Alas! It can be done! But I just need a very simple function to detect if there’s a shake action. So my actual code is a lot simpler:
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// Need to implement SensorListener public class ShakeActivity extends Activity implements SensorListener { // For shake motion detection. private SensorManager sensorMgr; private long lastUpdate = -1; private float x, y, z; private float last_x, last_y, last_z; private static final int SHAKE_THRESHOLD = 800; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ...... // other initializations // start motion detection sensorMgr = (SensorManager) getSystemService(SENSOR_SERVICE); boolean accelSupported = sensorMgr.registerListener(this, SensorManager.SENSOR_ACCELEROMETER, SensorManager.SENSOR_DELAY_GAME); if (!accelSupported) { // on accelerometer on this device sensorMgr.unregisterListener(this, SensorManager.SENSOR_ACCELEROMETER); } } protected void onPause() { if (sensorMgr != null) { sensorMgr.unregisterListener(this, SensorManager.SENSOR_ACCELEROMETER); sensorMgr = null; } super.onPause(); } public void onAccuracyChanged(int arg0, int arg1) { // TODO Auto-generated method stub } public void onSensorChanged(int sensor, float[] values) { if (sensor == SensorManager.SENSOR_ACCELEROMETER) { long curTime = System.currentTimeMillis(); // only allow one update every 100ms. if ((curTime - lastUpdate) > 100) { long diffTime = (curTime - lastUpdate); lastUpdate = curTime; x = values[SensorManager.DATA_X]; y = values[SensorManager.DATA_Y]; z = values[SensorManager.DATA_Z]; float speed = Math.abs(x+y+z - last_x - last_y - last_z) / diffTime * 10000; if (speed > SHAKE_THRESHOLD) { // yes, this is a shake action! Do something about it! } last_x = x; last_y = y; last_z = z; } } } } |
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