Replace

onboardPopupWindow.showAtLocation(this,Gravity.CENTER,0,0);

with

v.post(new Runnable() {
    public void run() {
        onboardPopupWindow.showAtLocation(v,Gravity.CENTER, 0, 0);
    }
});

I want to show my popupwindow in the middle of the screen. I’m calling it in OnCreate from the MainActivity. I cannot understand how I can get the parent view that showAtLocation is asking for :
public void showAtLocation(android.view.View parent, int gravity, int x, int y)

what I have is:

     List<Fragment> list=new ArrayList<>();
        list.add(new PageFragment1());
        list.add(new PageFragment2());
        list.add(new PageFragment3());


        LayoutInflater inflater = (LayoutInflater)this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View v = inflater.inflate(R.layout.onboarding, null);


        pager=v.findViewById(R.id.pager);
        pagerAdapter=new Onboard_SlidePageAdapter(getSupportFragmentManager(),1,list);
        pager.setAdapter(pagerAdapter);

        onboardPopupWindow = new PopupWindow(v,500, RelativeLayout.LayoutParams.WRAP_CONTENT, true);
        onboardPopupWindow.setElevation(10);

        onboardPopupWindow.showAtLocation(this,Gravity.CENTER,0,0);

I’m aware that I cannot pass “this” but there is no this.getView() or similar