SwipeDetectorIt should set as ontouch event of a View

ActivitySwipeDetector.java

import android.app.Activity;
import android.view.MotionEvent;
import android.view.View;

public abstract class ActivitySwipeDetector implements View.OnTouchListener {

 private Activity activity;
 static final int MIN_DISTANCE = 100;
 private float downX, downY, upX, upY;

 public ActivitySwipeDetector(final Activity activity) { 
  this.activity = activity;
 }

 public abstract void onRightToLeftSwipe(float distanceX);

 public abstract void onLeftToRightSwipe(float distanceX);

 public abstract void onTopToBottomSwipe(float distanceY);

 public abstract void onBottomToTopSwipe(float distanceY);

 public boolean onTouch(View v, MotionEvent event) {
  switch(event.getAction()){
  case MotionEvent.ACTION_DOWN: {
   downX = event.getX();
   downY = event.getY();
   //   return true;
  }
  case MotionEvent.ACTION_UP: {
   upX = event.getX();
   upY = event.getY();

   float deltaX = downX - upX;
   float deltaY = downY - upY;

   // swipe horizontal?
   if(Math.abs(deltaX) > MIN_DISTANCE) {
    // left or right
    if(deltaX <  0) { this.onLeftToRightSwipe(deltaX); return true; }
    if(deltaX > 0) { this.onRightToLeftSwipe(deltaX); return true; }
   }
//   else { Logger.logout( "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE); }

   // swipe vertical?
   if(Math.abs(deltaY) > MIN_DISTANCE){
    // top or down
    if(deltaY <  0) { this.onTopToBottomSwipe(deltaY); return true; }
    if(deltaY > 0) { this.onBottomToTopSwipe(deltaY); return true; }
   }
//   else { Logger.logout("Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE); }

   //     return true;
  }
  }
  return false;
 }
}