original Viewpager2 can scroll left&right to change page. And I want to add "down to up scroll" to use 'startActivity'
I tried like this...but
Viewpager2 viewpager;
viewpager.getChildAt(0).setonTouchListener(new View.onTouchListener() {
     @Override
     public boolean onTouch(View v, MotionEvent event) {
           gestureDetector.onTouchEvent(event);
           return true;
     }
});
It cannot work original viewpager's left&right scroll. I want to save original's, and add just another scroll. How can i do?
#I searched about onInterceptTouchEvent, DispatchTouchEvent... I cannot find how to use.
 
    