moving player right or left depending on swipe

Question

In my Player.java class, I want to incorporate a function that moves my player according to the left or right swipes. I also used time in seconds in order to vary the movement in an cyclic way:

'''
class MyGestureDetector extends SimpleOnGestureListener {
 @Override
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
 Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT-4:00"));
 Date currentLocalTime = cal.getTime();
 DateFormat date = new SimpleDateFormat("KK:mm");
 date.setTimeZone(TimeZone.getTimeZone("GMT-4:00"));
 String localTime = date.format(currentLocalTime);
 try {
 if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
 return false;
 // right to left swipe
 if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
 X-=K;
 int currentSeconds = cal.get(Calendar.SECOND);
 Y=Y*Math.cos(18.currentSeconds);
 } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
 X+=K;
 int currentSeconds = cal.get(Calendar.SECOND);
 Y=Y*Math.cos(18.currentSeconds);
 }
 } catch (Exception e) {
 // nothing
 }
 return false;
 }
'''

After some research, this is the class I included in player.java. So my question is: Is there a more efficient way to detect swiping directions(without creating any additional class) and what is your opinion about the code structure knowing that the objective is to change X according to swipe direction.

Thank you.

Answer 1

I changed some local variables and make them static variables, why ? because these are created and destroyed if you use serveral times the method onFling. The main Idea is to improve the performance and decrease the space your method uses.

Also I refactorized some pieces of code

class MyGestureDetector extends SimpleOnGestureListener {
 private static DateFormat date = new SimpleDateFormat("KK:mm");
 private static Calendar cal; 
 MyGestureDetector() {
 date.setTimeZone(TimeZone.getTimeZone("GMT-4:00"));
 }
 @Override
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
 cal = Calendar.getInstance(TimeZone.getTimeZone("GMT-4:00"));
 String localTime = date.format(cal.getTime());
 try {
 if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
 return false;
 // right to left swipe
 if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
 X -= K;
 Y *= Math.cos(18*cal.get(Calendar.SECOND)); //18 * currentSeconds i think
 } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
 X += K;
 Y *= Math.cos(18*cal.get(Calendar.SECOND));
 }
 } catch (Exception e) {
 // Perhaps if the program does nothing or have an unexpected behavior
 // you are silencing the cause (it has happened to me)
 e.printStackTrace();
 }
 return false;
 }

Hope it helped.