ViewPager detect when user is trying to swipe out of bounds

Question

I am using the ViewPager consisting of 6 pages to display some data. I want to be able to call a method when the user is at position 0 and tries to swipe to the right (backw

Answer 1

Thanks a lot to @Flavio, although i had to do some changes to his code because the callbacks methods were firing twice, also I added code to check if there was any registered listener, to avoid app crashing when there is no listener registered. This is the code I used to make it work, with both onSwipeOutAtStart and onSwipeOutAtEnd:

public class CustomViewPager extends android.support.v4.view.ViewPager {

    float mStartDragX;
    OnSwipeOutListener mOnSwipeOutListener;

    public CustomViewPager(Context context) {
        super(context);
    }

    public CustomViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setOnSwipeOutListener(OnSwipeOutListener listener) {
        mOnSwipeOutListener = listener;
    }

    private void onSwipeOutAtStart() {
        if (mOnSwipeOutListener!=null) {
            mOnSwipeOutListener.onSwipeOutAtStart();
        }
    }

    private void onSwipeOutAtEnd() {
        if (mOnSwipeOutListener!=null) {
            mOnSwipeOutListener.onSwipeOutAtEnd();
        }
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        switch(ev.getAction() & MotionEventCompat.ACTION_MASK){
            case MotionEvent.ACTION_DOWN:
                mStartDragX = ev.getX();
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev){

        if(getCurrentItem()==0 || getCurrentItem()==getAdapter().getCount()-1){
            final int action = ev.getAction();
            float x = ev.getX();
            switch(action & MotionEventCompat.ACTION_MASK){
                case MotionEvent.ACTION_MOVE:
                    break;
                case MotionEvent.ACTION_UP:
                    if (getCurrentItem()==0 && x>mStartDragX) {
                        onSwipeOutAtStart();
                    }
                    if (getCurrentItem()==getAdapter().getCount()-1 && x