Android: How to handle right to left swipe gestures

Question

I want my app to recognize when a user swipes from right to left on the phone screen.

How to do this?

Answer 1

OnSwipeTouchListener.java:

import android.content.Context; import android.view.GestureDetector; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener;  public class OnSwipeTouchListener implements OnTouchListener {      private final GestureDetector gestureDetector;      public OnSwipeTouchListener (Context ctx){         gestureDetector = new GestureDetector(ctx, new GestureListener());     }      @Override     public boolean onTouch(View v, MotionEvent event) {         return gestureDetector.onTouchEvent(event);     }      private final class GestureListener extends SimpleOnGestureListener {          private static final int SWIPE_THRESHOLD = 100;         private static final int SWIPE_VELOCITY_THRESHOLD = 100;          @Override         public boolean onDown(MotionEvent e) {             return true;         }          @Override         public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {             boolean result = false;             try {                 float diffY = e2.getY() - e1.getY();                 float diffX = e2.getX() - e1.getX();                 if (Math.abs(diffX) > Math.abs(diffY)) {                     if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {                         if (diffX > 0) {                             onSwipeRight();                         } else {                             onSwipeLeft();                         }                         result = true;                     }                 }                 else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {                     if (diffY > 0) {                         onSwipeBottom();                     } else {                         onSwipeTop();                     }                     result = true;                 }             } catch (Exception exception) {                 exception.printStackTrace();             }             return result;         }     }      public void onSwipeRight() {     }      public void onSwipeLeft() {     }      public void onSwipeTop() {     }      public void onSwipeBottom() {     } } 

Usage:

imageView.setOnTouchListener(new OnSwipeTouchListener(MyActivity.this) {     public void onSwipeTop() {         Toast.makeText(MyActivity.this, "top", Toast.LENGTH_SHORT).show();     }     public void onSwipeRight() {         Toast.makeText(MyActivity.this, "right", Toast.LENGTH_SHORT).show();     }     public void onSwipeLeft() {         Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();     }     public void onSwipeBottom() {         Toast.makeText(MyActivity.this, "bottom", Toast.LENGTH_SHORT).show();     }  });